Sensor arrangement with electrically controllable arrays

• US 7,208,077 B1
• Filed: 04/14/2000
• Issued: 04/24/2007
• Est. Priority Date: 04/14/1999
• Status: Expired due to Term

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Bredehorst, Reinhard, Bernt, Helmut, Albers, Joerg, Hintsche, Rainer, Seitz, Rene
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US09/958,633
• Time in Patent Office: 2,566 Days
• Field of Search: 204/194, 204/400, 204/403.01, 204/403.03, 204/403.04, 204/403.13, 204/403.14, 204/406, 204/409, 435/4, 435/7.1, 205/777.5, 205/782
• US Class Current: 205/782
• CPC Class Codes: G01N 27/3277 being a redox reaction, e.g. detection by cyclic voltammetry voltammetry per se G01N27/42, G01N27/48

Abstract

An electric sensor array which is provided with several sensor positions that each have at least two microelectrodes. Molecular substances can be detected electrochemically and charged molecules can be transported or handled using the array. Measuring procedures can be effected, especially using two addressing procedures, in which sensor positions can be individually addressed and electrochemically or electrically controlled by pairing or in groups for voltage or impedance measurements. For biomolecular assays, affinity-binding molecules can be immobilized at the sensor positions, between the microelectrodes, or on auxiliary surfaces.

Claims

1. An electrically controllable sensor arrangement comprising a plurality of arrays, each adapted for one of an electrochemical detection of molecular substances, transport and handling of charged molecules, wherein

more than two sensor positions are provided on a substantially planar carrier (1), each sensor position provided as an array (4) of at least two microelectrodes, to form more than two arrays;

a first guided wiring configured for electrically addressing the arrays (4) on said carrier (1), and a second guided wiring extending substantially perpendicular with respect to said first guided wiring;

wherein said first guided wiring allows for several sensor positions to be addressed by selecting at least one of row and column, for said addressed sensor positions to be read out substantially in parallel, but individually in an electric addressing procedure;

a further guided wiring attributed to said carrier (1), coupled to the sensor positions for transmitting measured signals from said addressed sensor positions;

an electrical control arrangement having said second guided wiring, for electric control at said more than two arrays (4), such that said arrangement continuously supplies a polarization voltage to arrays that are no longer addressed after terminating the electric addressing procedure as to addressed arrays effected via said first guided wiring, and the second guided wiring attributed to said carrier (1) is part of said electric control arrangement for sensor positions not addressed for a reading;

said guided wirings for at least one of the following;

generating at least one of an electric direct field and alternating field at said arrays,

detecting different electrochemical reactions or properties individually at said arrays,

electrically reading out events having occurred at a sensor position between two electric addressing procedures of said same sensor position,

transporting affinity-binding molecules onto one of said arrays, to a particular carrier being present there or into a gel being present there, independent of optical properties, and for immobilizing said molecules there.

2. Sensor arrangement according to claim 1, wherein said planar carrier (1) comprises one of silicon, glass, ceramic and plastic.

3. Sensor arrangement according to one of claims 1 and 2, wherein an electrode surface of said microelectrodes (3,3a′

) comprises one of carbon and a precious metal film.

4. Sensor arrangement according to claim 1, wherein said first guided wiring allows for an individual electric addressing of each said array sensor position.

5. Sensor arrangement according to claim 1, having electronic circuits, wherein at each individual sensor position, microelectrodes are addressable by a respective one of said electronic circuits such that electrochemical events may be read out, and after said readout, potentials for an uninterrupted polarization are maintained, to not affect an electric double layer at microelectrodes wetted with a liquid.

6. Sensor arrangement according to claim 1, wherein integrated circuits are provided as changeover switches (12,13;

12′

,13′

), said integrated circuits being part of said arrangement for electric control (20,21;

16,17).

7. Sensor arrangement according to claim 1, wherein electrochemical events are serially read out at least partly from said microelectrodes of an individual array (4) over time spaced intervals between individual addressing procedures of said array (4), providing measurements attributed to said individual array, for at least one of recording, storage and summing up.

8. Sensor arrangement according to claim 1, wherein said arrays (4) are controllable in electrically grouped groups via said first guided wiring (14,15;

16,17), a respective group of arrays being individually controlled and comprising at least two arrays.

9. Sensor arrangement according to claim 1, wherein a measuring and storing unit (22,23;

22′

,23′

) is associated with said at least two sensor positions, said measuring and storing unit being arranged to store measurements from said microelectrodes, representing the events at a time, prior to reading the measurements out electrically in a subsequent addressing step.

10. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein surfaces of the microelectrodes and auxiliary microelectrodes are made of different materials.

11. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein each individual sensor position comprises at least one pair of ultramicroelectrodes and wherein the ultramicroelectrodes have one of identical and different geometries.

12. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein said microelectrodes are arranged in pairs as interdigital fingers, wherein the fingers are one of covered by dot-shaped microelectrodes and band structures, arranged in one of a spiral and a circular configuration.

13. Sensor arrangement according to claim 1, wherein said microelectrodes arranged in pairs comprise vertically stacked plural layers including band-shaped metal films separated by insulating layers.

14. Sensor arrangement according to claim 1, further comprising additional electrode surfaces besides said microelectrodes, arranged at said sensor positions and not showing microelectrodes behavior.

15. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein said sensor positions are covered by liquids and wherein at least certain of said sensor positions may be supplied with one of reagents, analytes and mixtures of analytes.

16. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein at individual sensor positions, affinity-binding molecules also having different specificity are immobilized on at least one of:

said individual sensor positions;

auxiliary metallic surfaces;

surfaces of the carrier; and

, compartment walls, for effecting one of voltage and resistance measurements using said microelectrodes.

17. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein at individual sensor positions, affinity-binding molecules linked on said microelectrodes are removable by one of desorption and electrochemical oxidation.

18. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein a voltammetric detection is effected using one of liquid analytes independent of particular components, surface-mounted gels, and adhering substances.

19. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein an impedimetric detection is effected in liquid analytes independently of particular components.

20. Sensor arrangement according to claim 1, for electrochemically detecting molecular assays and for transporting charged molecules, wherein at each sensor position, individual molecular binding events are detected electrochemically after specifically linking analytes of mixtures of substances to said affinity-binding molecules immobilized at said sensor positions.

21. Sensor arrangement according to claim 1, wherein absence of molecular binding events is detected individually at each said sensor position, after analytes of mixtures of substances have formed a specific bond with said affinity-binding molecules immobilized at said sensor positions.

22. Sensor arrangement according to claim 1, wherein after analytes of mixtures of substances have formed a bond with said affinity-binding molecules immobilized at said sensor positions, individual molecular binding events are detected at each sensor position by using said microelectrodes by recording at least one of a quality and a quantity of redoxactive reaction products of binding-specifically introduced enzyme markers.

23. Sensor arrangement according to claim 1, wherein said individual sensor positions are separable by volume-separating compartments, for realizing a position-specific, quantitative electrochemical detection.

24. Sensor arrangement according to claim 1, wherein said microelectrodes comprise a precious metal and further comprising immobilization surfaces for self-assembling monolayers of different thiol-modified affinity-binding molecules on different sensor positions.

25. Sensor arrangement according to claim 24, wherein said self-assembling monolayers are formed by providing a similar coating with bi-functional thiol-modified molecules on all sensor positions, said molecules being used in a second reaction step for linking affinity-binding molecules at each individual sensor position.

26. Sensor arrangement according to claim 24, wherein said affinity-binding molecules immobilized at least at certain of said individual sensor positions of said electrically controllable sensor arrangement are coated with a layer of hydrogels.

27. Sensor arrangement according to claim 26, wherein said affinity-binding molecules immobilized at said individual sensor positions are coated with a layer of hydrogels, said hydrogels covering all of the arrays of the sensor arrangement.

28. Sensor arrangement according to claim 1, wherein different affinity-binding molecules are introduced into compartments at said individual sensor positions and fixed, and wherein the affinity-binding molecules are associated with one of polymers, nanoparticles of metals, mineral substances and gelatinous substances.

29. Sensor arrangement according to claim 1, wherein affinity-binding molecules are introduced at individual sensor positions and immobilized in a layer of hydrogels.

30. Sensor arrangement according to claim 1, further comprising an electric fields generator adapted for coupling between pairs of the microelectrodes associated with the electric sensor array, for moving charged molecules according to electrophoretic principles.

31. Sensor arrangement according to claim 1, further comprising an electric alternating fields generator coupleable to apply electric alternating fields for removing linked analyte molecules from said individual sensor positions depending on binding strength and charge.

32. Sensor arrangement according to claim 1, wherein a detectable effect is caused during said electric addressing procedure by said first guided wiring in said carrier, associated with said addressed sensor position (100).

33. Sensor arrangement according to claim 32, wherein a detectable effect is caused during an electric control by said second guided wiring in said carrier, associated with said non-addressed sensor positions.

34. Sensor arrangement according to claim 1, wherein said control arrangement comprises a direct link of said microelectrodes of said sensor positions to at least one potential (E, F) operable to supply current via the direct link.

35. Sensor arrangement according to claim 34, wherein said control arrangement comprises substantially loss-free direct lines from two microelectrodes (6,6′

;

3,3′

) of a respective sensor position to a source of a potential difference (3,F) providing a current supply, and wherein said source of the potential difference is spaced from said sensor positions.

36. Sensor arrangement according to claim 1, wherein during an electric control, a detectable reaction is coupled at said non-addressed sensor positions to said second guided wiring in said carrier.

37. Sensor arrangement according to claim 1, wherein an alternating switch is attributed to each microelectrode of each array (4), for switching said electrodes (3,3′

) of said array between a guided measuring wiring (18,19) and said second guided wiring (20,21) for providing a conservation voltage as polarization voltage.

38. An electrically controllable sensor arrangement comprising a plurality of arrays (4), adapted for electrochemically detecting molecular substances and adapted for one of transporting and handling charged molecules, said sensor arrangement having

more than two sensor positions on a substantially planar carrier (1), each sensor position being provided as an array (4) of at least two microelectrodes;

a first guided wiring for electrically addressing each array (4) on said carrier (1) and for coupling at least one microelectrode selected from said microelectrodes to at least one measuring line (18,19), oriented substantially perpendicular to said first guided wiring;

a second guided wiring oriented substantially perpendicular to said first guided wiring, for supplying an electric polarization voltage, chargeable with current, to said arrays, wherein after terminating a respective addressing procedure, non-addressed arrays are substantially continuously supplied from the electric polarization voltage;

an alternating switch connected to each electrode of each array, for switching electrodes of a respective one of said arrays between a guided measuring wiring, thereby coupling to said guided measuring wiring for measurement, and said second guided wiring, thereby applying a conservation voltage from said polarization voltage.

39. A control method for a sensor arrangement comprising a plurality of arrays (4) of at least two microelectrodes each, said sensor arrangement being provided with a first arrangement for addressing each array on a carrier, comprising the steps of:

effecting an addressing procedure for reading selected ones of the arrays;

after termination of the addressing procedure, continuing to supply no longer addressed arrays with a substantially constant polarization voltage by an electric control; and

employing said addressing procedure and said continuing to supply with said polarization voltage to the arrays for at least one of

generating at least one of an electric direct field and alternating field at said arrays;

detecting different electrochemical reactions or properties individually at said arrays;

electrically reading out the events having occurred at a sensor position between two electric addressing procedures of said same sensor position; and

transporting affinity-binding molecules onto one of said arrays, to a particular carrier being present there or into a gel being present there, independent of optical properties, and for immobilizing said molecules there.

40. Control method according to claim 39, comprising maintaining said substantially constant polarization voltage even when current loads occur at said no longer addressed arrays within a time interval of electric control.

41. Control method according to claim 39, wherein at least two switch functions are attributed to each array (4) as a sensor position, switching said array between a pair of measuring lines and a second guided wiring and provide a conservation voltage.