WO2002094442A1

WO2002094442A1 - Biosensor chip/dispenser arrangement and method for dispensing a solution to be dispensed using said dispenser device on a biosensor chip

Info

Publication number: WO2002094442A1
Application number: PCT/DE2002/001562
Authority: WO
Inventors: Roland Thewes; Eugen Unger
Original assignee: Infineon Technologies Ag
Priority date: 2001-05-22
Filing date: 2002-04-29
Publication date: 2002-11-28
Also published as: DE10124988A1; EP1392437A1

Abstract

The dispenser arrangement comprises a substrate (100). The substrate (100) has an upper and lower surface. The dispenser arrangement also comprises a dispenser device (103) for receiving a solution to be dispensed (104). The dispenser device (103) is arranged at a distance above the upper surface of the substrate (100) in such a way that the solution to be dispensed (104) can be dispensed above a given area (101) of the upper surface of the substrate (100). The substrate is electrically contacted in such a way that an electric potential can be generated between the given area and the dispenser device. The electric potential generated between the given area and the dispenser device makes it possible to control the direction in which the solution is dispensed towards said given area.

Description

description

Biosensor chip dispensing arrangement and method for dispensing a solution to be dispensed using the dispensing arrangement on a biosensor chip

The invention relates to a biosensor chip dispensing arrangement and a method for dispensing a solution to be dispensed using the dispensing arrangement on a biosensor chip

Bio- / chemo-arrays miniaturized on substrates serve the detection of certain molecules in solutions to be examined. The sensors are in large numbers on a semiconductor substrate, e.g. a silicon chip that certain electronic

Provides functions, realizable or on a substrate made of glass, plastic, or another substrate material. The high degree of parallelization enables a number of different examinations to be carried out simultaneously, e.g. Examinations for the presence of different substances (i.e. molecules to be detected) in a given liquid to be examined. This property results in a variety of applications for such sensor array chips with a corresponding evaluation system, for example in medical diagnostics, in the pharmaceutical industry, for example for high-throughput screening processes ("High Throughput Screening" (HTS)), in the chemical industry, in the Food analysis, as well as in environmental and food technology.

The basic principle of many known sensors is that so-called catcher molecules, for example with, are initially known in a position-specific manner on a substrate made of a suitable material Microdispensing techniques are applied and immobilized in various ways. 7 schematically shows such a substrate 700 with n positions 701, on each of which different capture molecules are immobilized. Such a substrate 700 is usually first brought into contact with the liquid to be examined at all positions for diagnosis (for example, to test a liquid to be examined for the presence of different molecules to be detected). Such contacting usually takes place by flooding the entire substrate 700 with the liquid to be examined. If the catcher molecules can bind to a molecule present in the liquid to be examined in a specific binding reaction according to the key-lock principle, according to which only those molecules in the liquid to be examined are bound by the catcher molecules for which the latter have a binding specificity, the molecule is specifically bound in the liquid to be examined by the capture molecules. If this is not the case, the molecule in the liquid to be examined is not bound by the capture molecule. Subsequent evaluation of the respective positions 701 of the substrate 700 then reveals whether a molecule or which molecule was present in the liquid to be examined.

Such substrates 700 are often used to detect nucleic acids in liquids to be examined. As described above, this takes place in that both the catcher molecule and the molecule to be detected in the liquid to be examined are both nucleic acids, ie DNA or RNA, with a specific binding being the complete or at least for hybridization of both nucleic acid strands requires sufficient complementarity between these two molecules.

However, other combinations between catcher molecules on the substrate 700 and molecules to be detected in the liquid to be examined are also possible. For example, nucleic acids can be used as capture molecules for peptides or proteins that bind specifically to nucleic acids. It is also known to use peptides or proteins as capture molecules for others

To use capture peptide or capture protein binding proteins or peptides. Of very great importance to the pharmaceutical industry is the use of low molecular weight (i.e. less than about 1,700 g / mol molecular weight) chemical compounds as capture molecules for these low molecular weight binding proteins or peptides and vice versa, i.e. the use of proteins and peptides as capture molecules for low-molecular compounds which may be present in a liquid to be examined.

It is known to use an optical detection method or an electronic detection method to detect the binding that has taken place between the capture molecule applied to the substrate and the molecule to be detected that is present in the liquid to be examined.

In a known optical method, a fluorescent marking substance (“label”) is specifically bound to the molecules present in the solution to be examined, which can be excited to glow when exposed to, for example, UV light. As a rule, this bond is a chemically covalent bond. Now the substrate after the Contacting the liquid to be examined and after a further rinsing step in which existing but not bound molecules in the liquid to be examined are removed with light can be determined on the basis of the knowledge of the location of the respective capture molecules at which positions of the Specific binding has occurred substrate and at which positions no specific binding has occurred. On the basis of the exact knowledge of the capture molecules used, it can be concluded that there are certain molecules in the liquid to be detected, or that none of them exist.

In comparison to a known electrical detection method, the optical detection method has the particular disadvantage that a relatively complicated and expensive optical system must be used for the evaluation. This makes e.g. the use of such an optical detection method in a doctor's office.

It is also known for the detection of the binding that has been made to use an electrical detection. Examples of such an electrical detection method are known from [1], [2], [3], [4], [5], [6], [7] and [8].

In both optical and electrical detection methods, capture molecules are immobilized on predetermined areas of a substrate. As a rule, this immobilization takes place by applying a solution containing these capture molecules to the predetermined area of the substrate by means of dispensing technology. The capture molecules present in this solution can then react with the respective predetermined area of the substrate to be immobilized on this. In optical detection methods, the predetermined area is often any area on the substrate which is discrete from other areas on the substrate, the nature of which is often identical to that of the rest of the substrate. In the case of electrical detection methods, the predetermined area is often an exposed electrode on the surface of the substrate or an electrode which is coated with another material, for example with the material of the rest of the substrate surrounding the electrode.

The following explains how the dispensing of a solution containing capture molecules to be immobilized is ideally applied to a predetermined area of a substrate by means of known dispensing technology.

In FIGS. 3A and 3B are a substrate 300, a predetermined area 301 of the substrate 300, a dispensing device 302 (here a nozzle), a solution 303 to be dispensed, large guide projections 304, and a cavity 306, which is above the predetermined area 301 is formed by the large guide projections 304.

3A and 3B show the case where the guide protrusions 304 are made relatively large so that they are able to completely absorb the dispensed volume of the solution 303. Figure 3A shows a drop of solution 303 that is being dispensed from nozzle 302. FIG. 3B shows the result after the solution 303 has been dispensed from the nozzle 302. It should be noted that the solution 303 in FIG

Area 301 completely wetted, which is the ideal case. In FIGS. 3C and 3D, a substrate 300, a predetermined area 301 of the substrate 300, a dispensing device 302 (here a nozzle), a solution 303 to be dispensed, small guide projections 305, and a cavity 306 that pass through the predetermined area 301 the small guide projections 304 is formed.

3A and 3B show the case that smaller guide protrusions 305 than that in Figs. 3A and 3B are provided. Figure 3C shows the drop of solution 303 as it is being dispensed from nozzle 302. 3D shows the case after dispensing the drop of solution 303 from the nozzle 302 such that this drop is now between the guide projections 305 above the predetermined range, but the volume of the drop of solution 303 in FIG. 3D is due of the small guide protrusions 305 cannot be fully received by them. For this reason, the drop of solution 303 extends upward beyond the guide protrusions 305, the surface tension of the solution 303 tending to maintain a generally spherical shape of the drop of the solution 303 above the predetermined area 301. It should be noted that the predetermined area 301 shown in Fig. 3D is complete, i.e. is evenly wetted by the drop of solution 303, which is the ideal case.

However, such an ideal case cannot usually be realized with conventional chip arrangements with sensor electrodes. Fig. A shows a substrate 800, a predetermined area 801 on the substrate 800, a solution 802 to be dispensed, large guide projections 803, an air bubble 804 enclosed during the dispensing between the solution 802 and the predetermined area 801, and by the 8B shows a substrate 800, a predetermined area 801 on the substrate 800, a solution 802 to be dispensed, small guide projections 805, an air bubble 804 enclosed during the dispensing between the solution 802 and the predetermined area 801, and cavity 806 formed by the small guide projections 805.

FIG. 8A corresponds to FIG. 3B, but an air bubble 804 is enclosed between the solution 802 and the predetermined 801 during the dispensing. Since the dispensing often takes place with very small volumes in the applications described above (for example with volumes in the nanoliter range), the air bubble 804 cannot move upwards in order to be discharged into the atmosphere surrounding the solution 802. For this reason, the air bubble 804 below the solution 802 remains in contact with the predetermined area 801, so that this area of the predetermined area 801 cannot contact any catcher molecules to be immobilized in the solution 802. Thus, none are to be immobilized

Capture molecules are immobilized on that area of the predetermined area 801 that lies below the air bubble 804, while capture molecules to be immobilized on the area of the predetermined area 801 that directly contacts the solution 802 are immobilized in the solution 802.

Thus, incomplete wetting of the predetermined area 801 with the solution 802 leads to the undesirable state that after the immobilization phase, a partial area of the predetermined area 801 has immobilized capture molecules, while another partial area of the predetermined area 801 has no immobilized capture molecules. In the later detection procedure, such a, uneven Immobilization of capture molecules on the specified area 801 leads to undesired measurement artifacts.

Another disadvantage with such dispensing methods in the prior art is that because of the small volumes used in such dispensing methods, the dispensing itself is often very imprecise with regard to the desired dispensing location. As explained above, such dispensing methods in the prior art are often carried out with very small volumes, for example with volumes in the nanoliter range. The volume of the solution to be dispensed is therefore often experienced per se because of its weight, a weight that is approximately as great as the force due to the air resistance that such a volume experiences during the dispensing. After exiting, for example, a nozzle in such a dispensing method, therefore, before the volume of the solution to be dispensed is at rest due to this air resistance, this volume can move to the side of the desired trajectory of this volume between the nozzle and the substrate, which means the exact placement of the volume of the dispensing solution on a specific location of the substrate difficult.

Furthermore, in [9] a micro portioner for liquids is known with a means for generating an electrical one

Potential difference between the outlet opening of a capillary and a location opposite it outside the capillary, the means being set up such that drops emerging from the capillary are torn off by means of the electrical potential difference.

Further devices for applying a liquid to a substrate are described in [10], [11], [12] and [13]. The invention is therefore based on the problem of improving the spatial accuracy with which a volume of the solution to be dispensed can be dispensed onto a substrate.

This problem is solved with a biosensor chip dispensing arrangement and a method for dispensing a solution to be dispensed onto a predetermined area of a substrate using the dispensing arrangement on a biosensor chip with the features according to the independent patent claims.

A biosensor chip dispenser arrangement has a substrate. The substrate has an upper surface and a lower surface. Furthermore, the dispensing arrangement has a dispensing device for receiving a solution to be dispensed. The dispensing device is arranged at a distance above the upper surface of the substrate such that the solution to be dispensed can be dispensed above a predetermined area of the upper surface of the substrate, the predetermined area of the upper surface of the substrate being set up in such a way that catcher molecules are applied to it are immobilizable. Here, the substrate is electrically contacted such that an electrical potential can be generated between the predetermined area and the dispensing device. The electrical potential generated between the predefined area and the dispensing device enables the direction of the dispensing of the solution to be dispensed to the predefined area to be controlled.

The biosensor chip dispensing arrangement according to the invention has the advantage that by applying an electrical Potential between at least the predetermined area of the substrate and the dispensing device, a volume of the solution to be dispensed is actively electrostatically drawn towards the target position, that is, the predetermined area of the substrate. Thus, the trajectory of a very small volume of the solution to be dispensed from the dispensing device is determined by the electrostatic field lines existing between the predetermined area of the substrate and the dispensing device, as a result of which the volume of the dispensed device migrates sideways

Solution outside the intended trajectory of the volume of the solution to be dispensed is reduced and therefore the location-specific accuracy with which the volume of the solution to be dispensed can be applied to the substrate is increased.

Furthermore, the active, electostatic drawing of the volume of the solution to be dispensed to a certain predetermined area reduces the risk that an air bubble is enclosed between the volume of the solution to be dispensed and the predetermined area of the substrate during dispensing. The volume of the solution to be dispensed is effectively drawn onto it by the field lines between the dispensing device and the predetermined area of the substrate, so that the volume of the solution to be dispensed clings closely to the predetermined area, i.e. completely and evenly wets the predetermined area of the substrate.

According to an embodiment of the invention

Biosensor chip dispensing arrangement, the electrical contacting of the substrate is set up in such a way that the electrical potential is applied to the entire surface of the substrate can be. In this scenario, between the entire upper surface of the substrate and the dispensing device, there is a potential for controlling a volume of the solution to be dispensed from the nozzle to the substrate, and the predetermined area of the substrate to which the solution to be dispensed is to be dispensed, represents a conceptually delimited subdivision of the entire upper surface of the substrate. Accordingly, the predetermined area according to this exemplary embodiment carries the same electrostatic charge as the entire upper surface of the substrate.

With a potential applied to the entire surface of the substrate, two options are preferably provided with regard to the structure of the substrate.

In the first possibility, the substrate itself consists of an electrically conductive material, and the electrical contact is a direct electrical contact between the substrate itself and a voltage source coupled to the substrate. Possible electrically conductive materials from which the substrate could consist are, for example, polysilicon or different metals such as gold.

Since in this embodiment the potential can be applied to the entire surface of the substrate, field lines between the dispensing device and the upper surface of the substrate come not only between the predetermined area of the substrate to which the solution to be dispensed is to be dispensed and the dispensing device, but also between other areas on the top surface of the substrate and the dispensing device. In this In this case, the flight path of the dispensed volume of the solution to be dispensed is determined by the shortest field line to the upper surface of the substrate. In the case of a dispensing device oriented perpendicular to the upper surface, this shortest field line is the field line which runs perpendicular to the predetermined area on the upper surface of the substrate. For this reason, it is important in such an embodiment to position the lateral position of the dispensing device as precisely as possible above the predetermined area of the substrate to which the solution to be dispensed is to be dispensed, so that the field lines determining the trajectory of the solution to be dispensed between the dispensing device and the predetermined area of the substrate is that field line from the plurality of field lines that is the shortest.

In a second exemplary embodiment, in which the potential is applied to the entire surface of the upper surface of the substrate, the substrate consists of a non-electrically conductive material and the electrical contact is an indirect electrical contact between the substrate and an electrically conductive body coupled to a voltage source , In this embodiment, the volume of the solution to be dispensed is not dispensed directly on the electrically conductive material, but rather on the non-electrically conductive material of the substrate. A preferred, non-electrically conductive material is silicon dioxide or silicon nitride. Preferred, electrically conductive materials from which the body coupled to the voltage source can be created include all metals with high electrical conductivity. For example, aluminum, gold, platinum, Copper, tungsten or palladium can be used as the material for the electrically conductive body.

According to an embodiment of the invention, this electrically conductive body connected to a voltage source is arranged within the substrate between the upper surface and the lower surface of the substrate.

According to another exemplary embodiment of the invention, the electrically conductive body connected to a voltage source is arranged below the lower surface of the substrate.

According to a further exemplary embodiment of the invention, the electrical contacting is created in such a way that the electrical potential can be applied to only a single predetermined region of the substrate. According to this exemplary embodiment of the invention, there are only field lines between the predetermined region of the substrate and the dispensing device, which symbolically represent an electric field that pulls a volume of the solution to be dispensed towards the substrate. No other potential or a potential repelling the volume of the solution to be dispensed is applied to other areas of the substrate that are not the predetermined area of the substrate. Since field lines, along which the solution to be dispensed is drawn towards the substrate, only exist between the desired predetermined area of the substrate and the dispensing device, the exact positioning of the dispensing device above the predetermined area of the substrate is not as important as in this exemplary embodiment of the invention both Embodiments of the invention in which the potential is applied to the substrate over the entire surface.

The substrate preferably consists of a non-electrically conductive material and the predetermined region of the substrate is an electrode which is coupled to a voltage source. According to such an embodiment of the invention, the electrode, that is to say the predetermined region of the substrate, is one of a plurality of electrodes on the upper surface of the substrate, on the position-specific relative to the other electrodes on the surface of the substrate, the volume of which is to be dispensed Solution attracting potential can be created.

According to a further exemplary embodiment of the invention, the electrode can be arranged not only above the surface of the substrate, but also below the upper surface of the substrate. According to such an embodiment, the solution to be dispensed is not dispensed directly onto the electrode itself, but rather onto the electrically non-conductive material of the substrate.

According to a particularly preferred exemplary embodiment of the invention, the electrode, which represents the predetermined region of the substrate, has gold. The use of gold not only enables high electrical conductivity, but also the immobilization of capture molecules applied to the electrode by means of a known gold-sulfur coupling.

In all of the preceding exemplary embodiments, a suitable, non-electrically conductive material is silicon dioxide or silicon nitride. Depending on the purpose However, other materials, for example polymeric materials such as polyethylene, polypropylene, polyethylene-polypropylene block copolymers, polystyrene, aluminum oxide, titanium oxide, and tantalum oxide can be used.

According to one embodiment of the invention, the dispensing device is a nozzle. The nozzle is preferably set up in such a way that the solution to be dispensed can be dispensed in volumes up to one nanoliter. For microdispensing purposes, for example, piezo micro nozzles are preferred.

In a further exemplary embodiment of the invention, the dispensing device, for example a nozzle, contains capture molecules to be immobilized. Because the solution to be dispensed is dispensed onto a certain predetermined area of the substrate, the capture molecules contained in the solution to be dispensed are applied in a location-specific manner to the predetermined area of the substrate, so that they can be immobilized on the substrate.

This presupposes that the nature of the specified area is such that a chemical, i.e. covalent, bond between the capture molecule to be immobilized and itself is possible. Depending on the structure of the substrate, a capture molecule contained in the solution to be dispensed can therefore be immobilized on either an electrically conductive material or a non-electrically conductive material.

According to a further exemplary embodiment of the invention, a dielectric layer is arranged above the upper surface of the substrate, so that the dielectric layer covers the upper surface of the substrate and if present, covers the electrode located on the top surface of the substrate. Although the electrode which may be located on the surface of the substrate is thereby covered, it is protected from external influences by such a dielectric layer. Whether a dielectric layer is applied to the upper surface of the substrate depends, for example, on how the capture molecules to be immobilized are to be immobilized or also how the electrical potential between the predetermined area of the substrate and the

Dispensing device of the dispensing arrangement is to be generated.

Such a dielectric layer, which can be applied to the upper surface of the substrate and, if present, to the electrode arranged on the upper surface of the substrate, can have silicon dioxide or silicon nitride.

According to a further embodiment of the invention, on the upper surface or, if present, on the

Dielectric layer arranged laterally upwardly extending guide projections.

Such guide projections have guide surfaces that lead inwards to the predetermined area. Such

Guide projections can be used to collect the solution to be dispensed in a targeted manner above the predetermined area of the substrate. The effect of the guide projections is particularly important in those cases in which incorrect placement of the volume of the solution to be dispensed is to be avoided laterally above the predetermined area of the substrate. This could be the case, for example, in the embodiment of FIG Case in which a potential can be applied to the entire surface of the substrate, so that between the

Dispensing device and the substrate several field lines can influence the trajectory of a volume of the solution to be dispensed. This could lead to an undesired "flowing away" of the volume of the solution to be dispensed from the predetermined area on the surface of the substrate. Such "missing" should therefore be avoided.

In a method for dispensing a solution to be dispensed onto a predetermined area of a substrate using the dispensing arrangement as explained above, the dispensing device and / or the substrate are moved relative to one another in such a way that, after the movement has been completed, the dispensing device is resting above the predetermined area comes. The predetermined area of the substrate is set up in such a way that capture molecules can be immobilized on it. In other words, the surface of the substrate in the predetermined area itself or an additional layer applied to the substrate in the predetermined area is set up in such a way that capture molecules can be immobilized on it. An electrical potential is applied between the predetermined area of the substrate and the dispensing device. The

Dispensing device is caused to dispense a volume of the solution to be dispensed. The potential existing between the dispensing device and the predetermined area of the substrate is allowed to act on the dispensed volume of the solution to be dispensed, so that a volume of the solution to be dispensed is controlled in the direction of the predetermined area. Embodiments of the invention are shown in the figures and are explained in more detail below.

Show it

Fig.l is a schematic representation of a

Embodiment of the biosensor chip dispensing arrangement according to the invention, in which a potential can be applied to the substrate over the entire surface;

2 shows an embodiment of the biosensor chip dispensing arrangement according to the invention, in which different potentials to different areas of the substrate are specific to the position

Substrate can be created;

3 shows a schematic representation of various

Biosensor chip dispensing arrangements according to the prior art;

4 shows a schematic representation of a

Embodiment of the biosensor chip dispensing arrangement according to the invention, in which a potential can be generated over the entire surface along the substrate by means of a body located in the substrate;

5 shows an embodiment of the biosensor chip dispensing arrangement according to the invention, in which a

Potential over the whole area along the substrate can be seen by means of a body located below the substrate;

6 shows an embodiment of the biosensor chip dispensing arrangement according to the invention, in which different potentials can be applied to different predetermined areas of the substrate and in which a dielectric layer is applied above the upper surface of the substrate;

7 shows an addressable substrate with a plurality of predetermined areas according to the prior art;

8 shows a schematic illustration of incomplete wetting of a predetermined area of a substrate using a dispensing arrangement according to the prior art.

1 shows a substrate 100, predetermined areas 101 of the substrate 100, a voltage source 102, a

Dispensing device 103 (here a nozzle 103), a solution 104 to be dispensed, field lines 105 along which the solution 104 to be dispensed is drawn towards the substrate 100, and an earthing device 106.

In the exemplary embodiment shown in FIG. 1, the substrate 100 is made of an electrically conductive material, so that the substrate 100 is directly, ie directly, coupled to a voltage source 102 in order to generate an electrical potential on the entire surface of the substrate 100. The substrate 100 has a plurality of predetermined regions 101, of which, viewed electrically, each predetermined region 101 is electrically separated from the surrounding upper surface of the substrate 100. The solution 104 to be dispensed contained in the nozzle 103 is in electrical contact with the nozzle 103. Since the nozzle 103 is grounded due to the grounding 106, the solution 104 to be dispensed contained in the nozzle 103 is also grounded. For this reason, there is between the upper surface of the substrate 100 and the predetermined areas 101 of the substrate 100 and the solution 104 to be dispensed, an electrical potential which is symbolically represented by the plurality of field lines 105. Since there is not only an electric field between the desired, here the central, predetermined area 101 and the solution 104 to be dispensed, but also between the nozzle 103 and the upper surface, the surrounding areas of the substrate 100 and the other predetermined areas 101 of the substrate 100 , The nozzle 103 should be positioned directly above the desired, here the central, predetermined area 101 of the substrate 100, so that the dispensed volume of the solution 104 to be dispensed along the shortest field line, here the field line 107, to the desired predetermined area 101 of the substrate 100 can be controlled.

2 shows a substrate 200, a positively charged, predetermined area 201 of the substrate 200, a dispensing device 202 (here a nozzle 202), a solution 203 to be dispensed, field lines 204, along which the solution 203 to be dispensed is drawn towards the substrate 200 field lines 205 along which the solution 203 to be dispensed is repelled from the substrate 200, a plurality of negatively charged predetermined regions 206 of the substrate 200, and an earth 207.

The substrate 200 consists of a non-electrically conductive material, for example of SiO ₂ , so that the predetermined regions 201, 206 of the substrate 200 are arranged and remain electrically insulated from one another. For this reason, different potentials can be applied to different predetermined areas 201, 206 of the substrate 200. In the embodiment shown in FIG. 2, it is desirable to dispense the solution 203 to be dispensed onto the predetermined area 201, wherein no solution 203 to be dispensed is to be dispensed onto the predetermined areas 206 of the substrate 200. If a volume of the solution 203 to be dispensed emerges from the nozzle 202, this is drawn to the predetermined region 201 of the substrate 200 due to the attractive electrical potential existing between the predetermined region 201 of the substrate 200 and the nozzle 202 along the field lines 204. In this case, the field lines 205 along which the solution 203 to be dispensed is repelled from the substrate 200 prevent the volume of the solution 203 to be dispensed from moving to other locations, for example to the predetermined areas 206 or to another location on the surface of the substrate

200, is drawn. For this, every given area should

201, 206 of the substrate 200 are individually coupled to a voltage source (not shown here). Accordingly, a position-specific potential is applied to a specific predetermined area of the substrate 200, here to the predetermined area 201, controlled by means of a computer and the individual couplings existing between the predetermined areas 201, 206 and the voltage source (not shown).

4 shows a substrate 400, a plurality of predetermined areas 401 on the upper surface of the substrate 400, a voltage source 402, a dispensing device 403 (here a nozzle 403), a solution 404 to be dispensed, field lines 405, along which the solution 404 to be dispensed is attracted towards the substrate 400, a body 406 made of electrical conductive material, a ground 407 and the shortest field line 408 between the nozzle 403 and the substrate 400.

In the exemplary embodiment shown in the figure, the substrate 400 consists of non-electrically conductive material and the predetermined regions 401 on the upper surface of the substrate 400 are to be understood as electrical regions of the upper surface of the substrate 400. As already explained above for FIG. 1, it is therefore important that the nozzle 403 must be positioned exactly above the desired predetermined area of the substrate 400, that is to say above the predetermined area 401 central in FIG. 4, so that the Volume of the solution 404 to be dispensed can be controlled along the shortest field line 408 between the nozzle 403 and the substrate 400 to this desired predetermined area 401 of the substrate 400.

As can be seen from the plus signs in FIG. 4, is introduced between the upper surface of the substrate 400 and the lower surface of the substrate 400

Body 406 a potential can be generated over the entire surface of the upper surface of the substrate 400. The body 406 is directly coupled to a voltage source 402 and is preferably made of metals with a high conductivity, such as aluminum, copper, gold, platinum, tungsten or palladium.

5 shows a substrate 500, a plurality of predetermined areas 501 on the upper surface of the substrate 500, a voltage source 502, a dispensing device 503 (here a nozzle 503), a solution 504 to be dispensed, field lines 505, along which the solution 504 to be dispensed is attracted toward the substrate 500, a body of electrically conductive material 506 below the lower surface of the Substrate 500, a ground 507 and a shortest field line 508 between the nozzle 503 and the substrate 500.

The body 506 shown in FIG. 5 is located under the lower surface of the substrate 500. Otherwise, the explanation for FIG. 4 applies accordingly to FIG. 5.

6 shows a substrate 600, a desired predetermined area 601 to which a solution 603 to be dispensed is to be dispensed, a dispensing device 602, field lines 604, along which the solution 603 to be dispensed is drawn towards the substrate 600, field lines 605, along which the solution 603 to be dispensed is repelled from the substrate 600, a plurality of predetermined areas 606 to which the solution 603 to be dispensed is not to be dispensed, a grounding 607 and a dielectric layer 608 on the upper surface of the substrate 600. The explanation of FIG applies accordingly to Fig. 6.

FIG. 6 differs from FIG. 2 in that a dielectric layer 608 is applied to the upper surface of the substrate 600. Accordingly, capture molecules which are contained in the solution 603 to be dispensed are not dispensed directly onto the predetermined area 601 (which is preferably an electrode in themselves), but rather are dispensed onto the dielectric layer 608 above the predetermined area 601.

The dielectric layer 608 could preferably consist of the same, non-electrically conductive material as the substrate 600. A suitable, non-electrically conductive material for this purpose, as already explained for FIG. 2, is silicon dioxide or silicon nitride. The applied dielectric layer 608 can be provided to protect the predetermined areas 601, 606 of the substrate 600, so that catcher molecules contained in the solution 603 to be dispensed are not dispensed directly on the conductive material of the respective predetermined area 601, 606, but on the dielectric layer 608 above the respective predetermined area 601, 606. In this regard, it may also be advantageous not to form the dielectric layer 608 flush with the material of the substrate 600, so that the dielectric layer 608 after the dispensing of different capture molecules on the respective predetermined areas 601 , 606 for further evaluation or detection can be separated from the substrate 600 with its predetermined areas 601, 606. This has the advantage that the position specificity of the predetermined areas 601, 606 of the substrate 600 results in a corresponding position specificity of the solution 606 dispensed in each case on the dielectric layer 608. Such a specific position transfer from the respective predefined areas 601, 606 of the substrate 600 to the dielectric layer 608 has the advantage that, using ever new dielectric layers 608, the dispensing arrangement, consisting of the substrate 600, the predefined areas 601, 606, the nozzle 602 and the grounding 607 can be used repeatedly.

7 and 8 have already been explained in the introductory part in the light of the prior art. The following references were cited in this document:

[1] M. Paeschke et al. , Electroanalysis 1996, 7, No. 1, p. 1-8

[2] R. Hintzsche et al. , "Microbiosensors using electrodes made in Si-technology", in "Frontiers in Biosensorics I

- Fundamental Aspects ", F. W. Scheller et al. Ed., 1997, Birkhauser Verlag Basel

[3] WO 93/22678

[4] DE 196 10 115 AI

[5] US Serial No 60/007840

[6] Peter Van Gerwen et al., Transducers '97, p. 907-910

[7] Christian Krause et al. , Langmuir, Vol. 12, No. 25, 1996 p. 6059-6064

[8] V. M. Mirsky, Biosensors & Bioelectronics 1997, Vol. 12 No. 9-10, pp. 977-989

[9] DE 24 54 104 AI

[10] US 3,914,312

[12] DE 42 29 005 AI

[13] US 4,740,799 LIST OF REFERENCE NUMBERS

100 substrate

101 Specified areas

102 voltage source

103 dispensing device (here a nozzle)

104 Solution to be dispensed

105 field lines along which the solution 104 to be dispensed is drawn towards the substrate 100

106 grounding

107 Shortest field line between the nozzle 103 and the substrate 100

200 substrate

201 positively charged, predefined areas

202 dispensing device (here a nozzle)

203 Solution to be dispensed

204 field lines along which the solution 203 to be dispensed is drawn towards the substrate 200

205 field lines along which the solution 203 to be dispensed is repelled by the substrate 200

206 Negatively charged, predetermined areas

207 grounding

300 substrate

301 Specified areas

302 dispensing device (here nozzle)

303 Solution to be dispensed 304 Large guide tabs 305 Small guide tabs

306 Cavity formed by the guide projections

400 substrate

401 Specified areas 402 voltage source

403 dispensing device (here nozzle)

404 Solution to be dispensed

405 field lines along which the solution 404 to be dispensed is drawn towards the substrate 400

406 body made of electrically conductive material 407 grounding

408 Shortest field line between nozzle 403 and substrate 400

500 substrate

501 predefined areas

502 voltage source

503 dispensing device (here nozzle)

504 Solution to be dispensed

505 field lines along which the solution 504 to be dispensed is drawn towards the substrate 500

506 body made of electrically conductive material

507 grounding

508 Shortest field line between nozzle 503 and substrate 500

600 substrate

601 Positively charged, specified area

602 dispensing device (here a nozzle)

603 Solution to be dispensed

604 field lines along which the solution 603 to be dispensed is drawn towards the substrate 600

605 field lines along which the solution 603 to be dispensed is repelled by the substrate 600

606 Negatively charged, predetermined areas

607 grounding

608 dielectric layer on the top surface of the substrate 600

700 chip / substrate

701 predefined areas

800 substrate

801 specified range

802 Solution to be dispensed

803 Great leadership

804 Air bubble trapped during dispensing

805 Small leadership tabs

806 Cavity formed by the guide projections

Claims

claims

1. Biosensor chip dispensing arrangement, with

A substrate that has an upper surface and a lower surface; and

A dispensing device for receiving a solution to be dispensed, which dispensing device is arranged at a distance above the upper surface of the substrate such that the solution to be dispensed is above a predetermined one

Area of the upper surface of the substrate can be dispensed, the predetermined area of the upper surface of the substrate being set up in such a way that capture molecules can be immobilized on it, • the substrate being electrically contacted such that an electrical potential exists between the predetermined area and the dispensing device can be generated so that the direction of dispensing the solution to be dispensed can be controlled towards the predetermined area.

2. Biosensor chip dispenser arrangement according to claim 1, in which the electrical contact is such that the electrical potential can be applied to the substrate over the entire surface.

3. The biosensor chip dispensing arrangement as claimed in claim 2, in which the substrate consists of an electrically conductive material, and the electrical contact is a direct electrical contact between the substrate and a voltage source coupled to the substrate.

4. biosensor chip dispenser arrangement according to claim 2, in which the substrate consists of a non-electrically conductive material, and the electrical contact is an indirect electrical contact between the substrate and an electrically conductive body coupled to a voltage source.

5. Biosensor chip dispenser arrangement according to claim 4, wherein the body connected to a voltage source

Inside the substrate between the upper surface and the lower surface of the substrate; or

Is arranged below the lower surface of the substrate.

6. The biosensor chip dispenser arrangement as claimed in claim 1, in which the electrical contact is such that the electrical potential can be applied to a single predetermined region of the substrate.

7. The biosensor chip dispenser arrangement as claimed in claim 6, in which the substrate consists of a non-electrically conductive material, and the predetermined region of the substrate is an electrode which is coupled to a voltage source.

8. biosensor chip dispenser arrangement according to claim 7, wherein the electrode

On the top surface of the substrate; or

Is arranged below the upper surface of the substrate.

9. biosensor chip dispenser arrangement according to claim 7 or 8, wherein the electrode comprises gold.

10. Biosensor chip dispensing arrangement according to one of claims 4, 5, 7, 8 or 9, in which the non-electrically conductive material comprises silicon dioxide, silicon nitride, polyethylene, polypropylene, polyethylene-polypropylene block copolymers, polystyrene, aluminum oxide, titanium oxide or tantalum oxide ,

11. Biosensor chip dispensing arrangement according to one of the preceding claims, in which the dispensing device is a nozzle.

12. The biosensor chip dispenser arrangement according to claim 11, in which the nozzle is set up in such a way that the solution to be dispensed can be dispensed in volumes of up to 0.1 nl or less.

13. Biosensor chip dispenser arrangement according to one of the preceding claims, in which the solution to be dispensed contains capture molecules to be immobilized on the predetermined area.

14. Biosensor chip dispenser arrangement according to one of the preceding claims, in which a dielectric layer is arranged above the upper surface of the substrate, so that the dielectric layer covers the upper surface of the substrate and, if present, the electrode arranged on the upper surface of the substrate ,

15. The biosensor chip dispenser arrangement as claimed in claim 14, in which the dielectric layer comprises silicon dioxide or silicon nitride.

16. Biosensor chip dispensing arrangement according to one of the preceding claims, in which on the upper surface or, if present, on the dielectric layer laterally extending guide projections are arranged on the side of the predetermined area.

17. A method for dispensing a solution to be dispensed onto a predetermined area of a substrate using the dispensing arrangement according to one of the preceding claims on a biosensor chip, the predetermined area of the substrate being set up in such a way that capture molecules can be immobilized on it, in which the dispensing device and / or the substrate are moved relative to one another in such a way that after the movement has been completed, the dispensing device comes to rest above the predetermined range;

• in which an electrical potential is applied between the predetermined area and the dispensing device;

In which the dispensing device is caused to dispense a volume of the solution to be dispensed; and • in which the potential existing between the dispensing device and the predetermined area is allowed to act on the dispensed volume of the solution to be dispensed, so that the volume of the solution to be dispensed is controlled in the direction of the predetermined area.

18. The method according to claim 17, in which the dispensing arrangement has a plurality of predetermined areas on the substrate, to which alternating potentials are applied in each case.