Sample carrier for electrical manipulation of liquid samples and for vibration spectroscopy on the samples

Description

Technical area

[0001] The invention relates to a method for producing a sample carrier and a sample carrier for electrical manipulation of liquid samples and for vibrational spectroscopy of the samples. Furthermore, the invention relates to a system for vibrational spectroscopy comprising a sample carrier and a vibrational spectroscope. Background of the invention

[0002] Bioassays or lab-on-a-chips are used to examine cells, especially bacteria and / or viruses. This method involves electrical manipulation of the cells on / in a microfluidic system, particularly a microfluidic chip suitable for vibrational spectroscopy. Dielectrophoretic chips are particularly used for Raman spectroscopy.

[0003] To date, these chips have been produced on an individual basis and consist of a planar substrate onto which electrodes are applied using lithographic processes. A polymer block, particularly polydimethylsiloxane (PDMS), is placed on this substrate, serving as a microfluidic chamber for the samples. To control the electrodes on the substrate layer, the substrate layer with the PDMS block is attached to a circuit board and electrically connected to it. Examples of such devices are US 2019 / 162655 A1 and WO 2018 / 200995 A2.

[0004] In this configuration, the number of available electrodes is determined by the size of the substrate. Thus, the number of sample chambers in the PDMS block that can be controlled by electrodes depends on the substrate. In-house production of the bioassay results in high production costs and cannot be mass-produced. Furthermore, using the PDMS block as a sample chamber can lead to cross-contamination between individual sample chambers of the PDMS block, as the PDMS block is primarily held in place by its hydrophobic properties. The inventors of the present invention have determined that this renders the existing bioassay unreliable and error-prone, complicating commercial application. Description of the invention

[0005] It is an object of the present invention to further develop the aforementioned approaches and thereby improve the study of cells, in particular the study of bacteria and viruses and their response to anti-infectives. In particular, it is an object of the present invention to provide an improved sample carrier, i.e., a bioassay, for improved Raman spectroscopic investigation of antibiotic resistance.

[0006] This object is achieved according to the invention by a sample carrier according to claim 1 and by a method for producing the sample carrier according to claim 15 and by a system according to claim 14. Further advantageous embodiments emerge from the dependent claims which refer back thereto.

[0007] A first aspect of the invention relates to a sample carrier for the electrical manipulation of liquid samples and for vibrational spectroscopy on the samples. The sample carrier comprises a substrate layer and a circuit board, wherein the circuit board is arranged on the substrate layer. The substrate layer has a plurality of electrodes for the electrical manipulation of liquid samples, wherein the circuit board has electrical leads to the electrodes of the substrate layer, and wherein the circuit board has a plurality of recesses, each of which, together with the substrate layer, forms a sample chamber. The electrodes are configured to generate an inhomogeneous electric field for dielectrophoresis.

[0008] A second aspect of the invention comprises a system for vibrational spectroscopy comprising a vibrational spectroscope and a sample carrier according to the invention. A third aspect of the invention relates to a method for producing a sample carrier for the electrical manipulation of liquid samples and for vibrational spectroscopy on the samples. The method comprises providing a substrate layer, applying a plurality of electrodes for the electrical manipulation of liquid samples to the substrate layer, providing a circuit board, applying electrical leads to the electrodes of the substrate layer to the circuit board, forming a plurality of recesses on the circuit board, and arranging the circuit board on the substrate layer, wherein the recesses each form a sample chamber together with the substrate layer, wherein the electrodes are configured to generate an inhomogeneous electric field for dielectrophoresis.

[0009] A sample carrier can be understood, in particular, as a vessel for holding liquid samples, wherein various structural features for analyzing these liquid samples are provided on and / or on the sample carrier, as will be explained in more detail below. The sample carrier is suitable for being introduced into a vibrational spectroscopic measuring device. Furthermore, the sample carrier is designed such that it can hold a plurality of liquid samples, making it possible to analyze this plurality of liquid samples using a vibrational spectroscope. The sample carrier can also be referred to as a bioassay. In its basic structure, the bioassay comprises a microfluidic chip, which enables sample manipulation by dielectrophoresis, as will be described below, particularly in the context of various exemplary embodiments.

[0010] Electrical manipulation can be understood as electrokinetic manipulation. In particular, it can be understood as manipulation based on dielectrophoresis. In dielectrophoresis, an inhomogeneous electric field is used to manipulate particles. The inhomogeneous electric field induces a dipole moment in the particles, which interacts with the applied field. The particles are thus subjected to a force and move into areas of high or low field strength depending on the field and the dipole moment. The force is proportional to the volume of the particles. Thus, particles can also be captured depending on their size. Dielectrophoresis is used, among other things, for the detection and sorting of bacteria and viruses within the sample carrier. In complex liquid samples, such asIn saliva, urine, or blood, the bacteria must first be separated from other components of the liquid sample, as these other components make identification more difficult. The bacteria are captured and held using dielectrophoresis, making them accessible for analysis. This allows the bacteria to be measured directly in the liquid sample in which they are contained. The previously described method steps and corresponding structural limitations are therefore considered part of embodiments of the invention.

[0011] Vibrational spectroscopy is an analytical measurement method based on the excitation of the normal vibrations of molecules. Vibrational spectroscopy methods include infrared spectroscopy and Raman spectroscopy. Vibrational spectroscopy is used, for example, to characterize compounds. It is used to identify known compounds, determine components of an unknown compound, determine the structure of a compound, determine concentration changes of components during a reaction, determine binding properties, and determine organic and inorganic substances, especially molecules. In particular, it can be used to identify bacteria and their response to antibiotics. A spectrum of a bacterium is sufficient to identify that bacterium. In particular, each bacterial species has a unique Raman signature.For example, in Raman spectroscopic testing to determine the susceptibility or resistance of bacteria to antibiotics, the growth curves of bacteria under the influence of antibiotics are measured. The previously described method steps and corresponding structural limitations are therefore to be considered part of embodiments of the invention.

[0012] Furthermore, the particles or cells in the sample carrier can also be used for fluorescence investigations or for general morphological investigations.

[0013] Liquid samples can be understood, in particular, as liquid media containing cells to be examined, especially bacteria and / or viruses. Bacteria can be cultivated in the sample carrier within the liquid samples and then analyzed directly in the sample carrier. Alternatively, the liquid samples, such as blood, urine, or saliva, can be taken externally and then applied to / into the sample carrier for analysis. For example, different antibiotics can be present in the sample chambers at different concentrations, into which the sample is added in order to subsequently examine the sample's reaction to the different concentrations or different antibiotics.

[0014] The sample carrier comprises a substrate layer and a circuit board. The substrate layer can be any material that is permeable to vibrational spectroscopy. In particular, the substrate layer is a transparent substrate layer made of plastic and / or glass. Depending on the selected substrate material, the background signals generated during sample data analysis are corrected, or the spectral band of the substrate differs sufficiently in wavenumber from the spectral band of the sample. Preferably, the substrate layer consists of a single, identical material.

[0015] A printed circuit board (PCB) can be a single-layer or multi-layer structure that supports electrically conductive structures and simultaneously serves as a sample receptacle. The PCB can be a commercially available PCB comprising electrically insulating and electrically conductive material. By using a PCB in the sample carrier, its industrial production can be simple, precise, automated, and cost-effective in large quantities. Unlike a PDMS block, the PCB can be mass-produced and is therefore particularly suitable for commercialization. Furthermore, the assembly process is simplified by simple assembly steps and commercially available fastening devices on the PCB.By using the circuit board, the previous bond wires that connect the PDMS block to the substrate and another circuit board can be avoided, thus allowing more reliable and longer-lasting components (than bond wires) to be used.

[0016] The circuit board is placed on the substrate layer, so that the top layer of the sample carrier represents the circuit board. The recesses on the circuit board extend through the circuit board at least to the substrate layer, so that the recesses are accessible for the introduction of liquid samples. This can be seen, for example, in the embodiments of the Figure 1The recesses in the circuit board can be designed as through-holes. This allows for easy production of the recesses. The recesses, together with the substrate layer, each form a sample chamber, i.e. there are preferably several sample chambers on the sample carrier. The number of sample chambers, also called wells, can preferably be in a range from 1 to 1600 sample chambers. In particular, the number of sample chambers is in a range from 6 to 1536. Preferably, the sample carrier comprises 384 sample chambers, in a 16 by 24 arrangement, according to a standard 354 well plate format. The denser wiring of the supply lines enables an increase in the number of sample chambers per area, since the wiring can be relocated from the substrate layer to the circuit board and more electrodes or electrode structures for controlling the sample chambers can be provided on the substrate layer.

[0017] According to an exemplary embodiment of the invention, the recesses extend both through the circuit board and at least partially through the substrate, so that the substrate also has recesses that are each associated with the recesses in the circuit board and, together with them, each constitute a sample chamber. This enables an increase in the sample volume.

[0018] Because a circuit board simultaneously serves to provide electrical leads and sample chambers, a higher number of sample chambers can be implemented, this can be exemplified in the embodiment of the Figure 2There is no longer any restriction regarding the number of electrodes, as the electrical leads can be arranged on the circuit board and no longer only on the substrate layer. By using the circuit board, the sample carrier becomes cheaper to manufacture overall, and this design now makes it suitable for large-scale production. This makes the sample carrier or bioassay more cost-effective. Furthermore, it is now possible to arrange more electrodes on the substrate layer, as the leads on the substrate layer can be omitted and arranged on the circuit board. This means that more and different electrode structures can be realized on the substrate layer.

[0019] According to an exemplary embodiment of the invention, the circuit board has a first main surface and a second main surface, wherein the first main surface is arranged opposite the second main surface, and wherein the electrical leads of the circuit board to the electrodes of the substrate layer are arranged both on the first main surface and on the second main surface.

[0020] By using a printed circuit board, it is possible to increase the number of electrical connections, in particular the supply lines, by arranging them on several, i.e. on the first and the second main surface. This means that more electrodes can be used for the examination, which at the same time results in an increase in the number of samples to be examined. The first main surface and the second main surface extend in a direction perpendicular to a direction in which the layers of the sample carrier are stacked on top of one another. Depending on the embodiment, the supply lines are arranged only on the first main surface or only on the second main surface, or the first main surface has more supply lines than the second main surface or exactly the other way around. Furthermore, the first and the second main surface can have the same number of supply lines.The number of supply lines depends on the number of electrodes to be controlled. In particular, one supply line is provided for each electrode. Additionally, supply lines for supplying electrical energy, current and / or voltage, can be provided on the first main surface and / or the second main surface.

[0021] According to an exemplary embodiment of the invention, the substrate layer consists of glass on or in which the electrodes are arranged.

[0022] The electrodes can be applied to or into the substrate layer using a lithographic process. The number of electrodes depends on the number of sample chambers, so that a corresponding electrode and / or electrode formation is provided for each sample chamber. If the substrate layer is made of glass, the sample carrier can be used for vibrational spectroscopy.

[0023] According to an exemplary embodiment of the invention, the glass is a quartz glass.

[0024] Quartz glass has the advantage of being made of pure silicon dioxide and, unlike other types of glass, contains no impurities that can produce interfering bands and thus affect vibrational spectroscopy. If a different transparent material is used, the results must be processed to filter out errors caused, for example, by scattering in the material caused by inclusions. These errors can be almost completely avoided when using quartz glass.

[0025] According to an exemplary embodiment of the invention, the electrodes of the substrate layer are designed as duopole, tripole, and / or quadrupole and for dielectrophoretic manipulation of the samples in the sample chambers. A quadrupole arrangement can, for example, be used in the embodiment of the Figure 5For the various electrode-pole arrangements, alternatingly poled electrodes are used. Specifically, for a quadrupole, two electrodes are arranged alternately to generate a positive electrical charge and two electrodes to generate a negative electrical charge. By arranging electrodes with different polarities, the liquid sample in the sample chambers can be dielectrically influenced.

[0026] According to an exemplary embodiment of the invention, one duopole, tripole, or quadrupole of electrodes is arranged on the substrate layer for each sample chamber. Thus, for a plurality of sample chambers, a plurality of duopoles, tripoles, or quadrupoles are arranged on the substrate layer. The number of duopoles, tripoles, or quadrupoles depends on the number of sample chambers.

[0027] According to an exemplary embodiment of the invention, the volume of each sample chamber is in the range of 0.5 to 50 µl. In particular, the volume of each sample chamber is in the range of 0.5 to 30 µl, in particular in the range of 0.5 to 10 µl, in particular from 0.5 to 5 µl inclusive. The smaller the volume of the sample chamber, the more sample chambers the circuit board can comprise and the more samples can be analyzed. According to an exemplary embodiment, the sample chambers can have different volumes.

[0028] According to an exemplary embodiment of the invention, a connecting layer is arranged between the circuit board and the substrate layer. The connecting layer is configured to connect the circuit board to the substrate layer. The connecting layer can extend partially or completely between the substrate layer and the circuit board. The connecting layer can connect the substrate layer to the circuit board selectively, i.e. at individual positions, or over the entire surface of the substrate layer and the circuit board. The connecting layer can, for example, only extend along the outer layer edges between the substrate layer and the circuit board, in such a way that the connecting layer encloses a space free of the connecting layer, which can comprise the sample chambers. Furthermore, the connecting layer can only be provided at individual positions between the substrate layer and the circuit board.For example, the bonding layer is only arranged at the outer corners between the substrate layer and the circuit board. The bonding layer can be designed to seal the sample chamber between the substrate layer and the circuit board, preventing cross-contamination between the individual sample chambers.

[0029] According to an exemplary embodiment of the invention, the connecting layer is an adhesive layer, wherein the adhesive layer has recesses, and wherein one recess of the adhesive layer is arranged for each recess of the circuit board. In particular, the connecting layer is a two-sided adhesive film.

[0030] According to a further exemplary embodiment of the invention, the connecting layer is a magnetic layer such that the substrate layer and the circuit board are magnetically connected to each other.

[0031] According to an exemplary embodiment of the invention, the recesses in the adhesive layer, together with a recess in the circuit board and the substrate layer, each form a sample chamber. In other words, the sample chamber extends through both the circuit board and the adhesive layer, enabling vibrational spectroscopy of the liquid sample. The recesses in the adhesive layer are assigned to the recesses in the circuit board, i.e., each individual recess in the circuit board is assigned a recess in the connecting layer, with the shape of the recesses in the adhesive layer corresponding to the shape of the recesses in the circuit board.

[0032] According to an exemplary embodiment of the invention, the substrate layer has multiple leads to the electrodes. The electrical leads can thus be arranged both on the substrate layer and on the circuit board. This increases the number of leads and allows more electrodes to be controlled. Thus, various electrode structures can be formed, which can be controlled differently. The number of samples to be analyzed can thus also be increased.

[0033] According to an exemplary embodiment of the invention, the electrodes of the substrate layer are arranged at least partially one above the other. An insulation layer can be arranged between the electrodes arranged one above the other to insulate the electrodes from one another, and furthermore, the electrical leads can be arranged at least partially on the substrate layer. According to this embodiment, the substrate layer has a plurality of electrodes which are arranged one above the other on one side of the substrate layer. The plurality of electrodes can be arranged in several layers on one side of the substrate layer, wherein the electrode layers are arranged directly one above the other and / or offset one above the other, depending on the selected electrode formation. The electrodes are arranged in particular on a side of the substrate layer which faces the printed circuit board, so that the electrodes orThe electrode layers are located between the substrate layer and the circuit board. Alternatively or additionally, the electrodes can also be arranged on the side of the substrate layer facing away from the circuit board. Furthermore, this embodiment can contain an additional layer between the superimposed electrodes on the substrate layer, wherein this layer is configured as an insulation layer and / or passivation layer. This insulation layer allows the superimposed electrode structures to be arranged directly on top of one another, thus preventing cross-over and short-circuiting of the various electrode structures.In an exemplary embodiment, the connecting layer described in the other embodiments can be used, for example, as the insulating layer, or the insulating layer can be an additional layer between the circuit board and the substrate layer, in particular between the connecting layer and the substrate layer. The insulating layer can, for example, be applied only partially between the electrode structures arranged one above the other, so that the insulating layer is only located between the electrode structures that would cross or overlap. By arranging the electrode structures, a plurality of electrical leads can also be shifted to the substrate layer, thus reducing the number of electrical leads and through holes on the circuit board.According to this embodiment, the remaining electrical leads on the circuit board can be relocated to the edge of the circuit board, so that, for example, only electrical leads and electrical contacts are required for electrically connecting the sample carrier to an analysis system, e.g., a frequency generator. A combination of this exemplary embodiment is possible with all other described embodiments.

[0034] According to an exemplary embodiment of the invention, the electrical leads of the printed circuit board extend at least partially through the printed circuit board. In particular, the electrical leads on the first main surface extend through the printed circuit board to the second main surface. In this embodiment, the first main surface represents a surface located on the side of the printed circuit board facing away from the substrate layer. The electrical leads on the second main surface can, for example, be brought into direct electrical contact with the electrodes of the substrate layer, since these do not have to extend through the printed circuit board. Alternatively, the electrical leads on the second main surface can extend within the printed circuit board, so that there are no elevations on the second main surface due to leads.This creates a planar second main surface of the circuit board, which can establish direct and secure contact with the substrate layer and / or the interconnect layer. By extending the electrical leads through the circuit board, bonding wires can be avoided and direct contact between the circuit board and the substrate layer is provided. This makes the sample carrier more reliable in its application.

[0035] According to an exemplary embodiment of the invention, the circuit board has a plurality of through-holes for the electrical leads, wherein the electrical leads extend through the through-holes to the electrodes of the substrate layer. In particular, the through-holes extend from the first main surface through the circuit board to the second main surface of the circuit board. According to one embodiment, the through-holes can have inner walls coated with electrically conductive material. This allows an electrical connection to be better provided by means of the through-holes. For example, conductive paste, in particular conductive silver, can be used for contacting and is introduced into the through-holes. The leads are thus realized through the through-holes by means of conductive paste.

[0036] According to an exemplary embodiment, the electrical leads are formed by at least one of an electrically conductive medium, an electrically conductive foil, an electrically conductive lacquer, an electrically conductive connector, and an electrically conductive clamp connection. The electrically conductive medium can, for example, be conductive silver, which is filled into the corresponding through-holes for the leads; the foils can, for example, be conductive adhesive foils. These electrical leads can be used to establish electrical contact between the substrate layer and the circuit board. Alternatively, these variants of the electrical leads can also be used to contact the circuit board with an external system, such as a frequency generator.Furthermore, contact pads can be provided on the circuit board and / or the substrate layer to connect the circuit board to an external system. For example, spring contact pins or other conductive spring elements can be used for contacting. The contact pads can be arranged on the bottom and / or top side of the circuit board. Alternatively or additionally, contact ports can also be arranged on the circuit board for connection to, for example, a frequency generator, whereby a plug connection is established between the circuit board and the function generator.

[0037] According to a further exemplary embodiment, an electrical connection or contact can be established between the substrate layer and an external system, such as the function generator. On the one hand, the substrate layer can extend beyond the circuit board in a direction perpendicular to a layer direction of the substrate layer and the circuit board. In other words, the substrate layer extends at least partially on one side in a direction perpendicular to the layer direction beyond the circuit board and / or the substrate layer is larger than the circuit board in this direction. On the region of the substrate layer extending beyond the circuit board, corresponding free-standing contact pads can be provided in order to provide contact by means of the variants described in the other embodiments. A contact can be connected to these contact pads in a materially bonded manner, for example via a flexible circuit board (e.g.A voltage source can be created using a foil (e.g., a film with applied conductor tracks). Alternatively, contact can be made directly on the substrate layer using spring contact pins.

[0038] Furthermore, the connecting layer also has holes and / or through-holes so that the electrical leads extend through the through-holes of the connecting layer when the connecting layer is arranged between the substrate layer and the circuit board.

[0039] According to an exemplary embodiment of the invention, when using the electrodes as a duopole, tripole, and / or quadrupole, the electrical leads do not overlap in a direction perpendicular to a layer direction of the substrate layer and the circuit board. This ensures that the different potentials of the electrodes do not influence each other and that a reliable, inhomogeneous field can be applied for dielectrophoresis. The term "layer direction" can be understood as a direction in which the circuit board, substrate layer, and connecting layer are layered or stacked on top of each other.

[0040] According to an exemplary embodiment of the invention, the sample carrier further comprises a seal arranged on the circuit board. The sample chambers are covered by this seal. In particular, the seal is arranged on the first main surface of the circuit board. The seal seals each sample chamber individually, so that contamination from external influences can be prevented by the seal. Furthermore, the user of the sample carrier can be protected from an infectious sample by the seal. In particular, the seal is designed to be removable, so that it can be removed or applied before and after and / or during the spectroscopic examination. This is important, for example, to protect against the toxicity of antibiotics in a bacteriophage sample.

[0041] According to an exemplary embodiment of the invention, the system comprises a detector for vibrational spectroscopy, wherein the detector is arranged on a side of the substrate layer opposite the circuit board. In other words, the detector is arranged below the sample carrier, on the side of the substrate layer. The vibrational spectroscope of the system is arranged on top of the sample carrier. Preferably, the detector is configured to perform Raman spectroscopy and / or infrared spectroscopy.

[0042] According to an exemplary embodiment, both the detector and the vibrational spectroscope are arranged on a side of the substrate layer opposite the circuit board. This means that the detector and vibrational spectroscope are arranged on the same side. For example, in an inverse Raman spectrometer, the sample is excited from below by a laser beam emitted by an objective lens. Some of the emitted photons are reflected back into the objective lens, are then deflected by a beam splitter, pass through a grating, and are detected by a detector, for example, a CCD detector.

[0043] According to an exemplary embodiment of the invention, the method further comprises providing a connecting layer and arranging the connecting layer between the substrate layer and the circuit board. In particular, the connecting layer is arranged between the substrate layer and the circuit board in such a way that they are mechanically connected to one another. Furthermore, the connecting layer can serve to seal the sample chambers. Short description of the drawings

[0044] For further explanation and better understanding of the present invention, exemplary embodiments are described in more detail below with reference to the accompanying drawings, without limiting the subject matter of the invention. They show: Fig. 1 shows a sample carrier according to an exemplary embodiment of the invention. Fig. 2 shows a sample carrier according to an exemplary embodiment of the invention. Fig. 3shows a sample chamber of a sample carrier according to an exemplary embodiment of the invention. Fig. 4 shows a system for vibrational spectroscopy comprising a sample carrier according to an exemplary embodiment of the invention. Fig. 5 shows a duopole arrangement and a sample chamber according to an exemplary embodiment of the invention. Fig. 6 shows a duopole arrangement according to an exemplary embodiment of the invention. Fig. 7 shows a pin array for contacting a sample carrier according to an exemplary embodiment of the invention. Detailed description of exemplary embodiments

[0045] Identical or similar components in different figures are provided with the same reference numerals. The representations in the figures are schematic and not to scale.

[0046] Figure 1illustrates a sample carrier 100 for the electrical manipulation of liquid samples and for vibrational spectroscopy on the samples according to an exemplary embodiment of the invention. The sample carrier 100 has a substrate layer 103 and a circuit board 101, wherein the circuit board 101 is arranged on the substrate layer 103. The substrate layer 103 has a plurality of electrodes 104, in particular electrodes 104a for applying negative charge and 104b for applying positive charge, for the electrical manipulation of liquid samples. The circuit board 101 has electrical leads 106 to the electrodes 104 of the substrate layer 103. Furthermore, the circuit board 101 has a plurality of recesses 105, which each form a sample chamber together with the substrate layer 103. The substrate layer 103 in Figure 1has a quadrupole electrode structure. To form a quadrupole, the electrodes 104a, 104b are arranged alternately, ie a quadrupole has four electrodes 104, in particular it has two electrodes 104a for applying negative charge and two electrodes 104b for applying positive charge. On the substrate layer 103 in Figure 1the electrodes 104 are arranged in a 5 by 9 matrix. In this arrangement, for example, 32 quadrupoles can be formed. For example, if the circuit board has recesses in the 384 well plate format, then the electrodes or the electrode structures are also arranged at intervals according to the 384 well plate format, so that each recess is assigned a corresponding electrode structure. The circuit board has a plurality of electrical leads 106 to the electrodes 104 of the substrate layer 103. Furthermore, the circuit board 101 has a first main surface 113 and a second main surface (not visible). The second main surface lies opposite the first main surface 113 and the electrical leads 106 to the electrodes 104 of the substrate layer 103 are arranged on both the first main surface 113 and the second main surface.The substrate layer 103 is transparent and consists of glass, in particular quartz glass. The electrodes 104 on the substrate layer 103 can be arranged at least partially one above the other, not shown in FIG. Figure 1. In this case, an insulation layer can be arranged between the superimposed electrodes 104 to insulate the electrodes 104 from one another, and furthermore, the electrical leads 106 can be arranged at least partially on the substrate layer. Thus, the substrate layer 103 would have a plurality of electrodes 104 arranged one above the other on one side of the substrate layer 103. The plurality of electrodes 104 can be arranged in several layers on one side of the substrate layer 103, wherein the electrode layers 104 are arranged directly above one another and / or offset from one another, depending on the selected electrode formation. The electrodes 104 are arranged in particular on a side of the substrate layer 103 that faces the circuit board 101, so that the electrodes 104 or the electrode layers are located between the substrate layer 103 and the circuit board 101.Alternatively or additionally, the electrodes can also be arranged on the side of the substrate layer 103 facing away from the circuit board 101. The insulation layer can be the connecting layer 102, or the insulation layer can be implemented as an additional layer (not shown) between the substrate layer 104 and the circuit board 101.

[0047] As in Figure 1As can be seen, the electrical leads for the positive charge are arranged on the first main surface 113. The electrical leads 106 for the negative charge can be arranged on the second main surface, which is not visible here. This means that the individual leads for the different charge potentials do not overlap, and an inhomogeneous field for dielectrophoresis can be reliably created. In particular, when the electrodes are used as a duopole, tripole, or quadrupole, the leads 106 do not overlap in a direction perpendicular to a layer direction of the substrate layer 103 and the circuit board 101. The electrical leads 106 of the circuit board 101 extend at least partially through the circuit board 101. In this sense, the electrical leads 106 on the first main surface 113 extend through the circuit board.In particular, the electrical leads 106 extend from the first main surface 113 through through-holes 107 to the second main surface. The through-holes 107 and 108 are provided in addition to the recesses 105 on the circuit board 101. By means of the through-holes 107 and 108, the electrical leads 106 on the circuit board 101 can be electrically connected to the electrodes 104 on the substrate layer 103. This connection can be established, for example, using a conductive paste, such as conductive silver. For this purpose, the through-holes for the electrical leads can have conductively coated inner walls to ensure better contact through the circuit board. The circuit board according to . Figure 1 It has 32 recesses, which together with the substrate layer form 32 sample chambers. Each sample chamber is assigned a quadrupole.

[0048] Furthermore, a connecting layer 102 is arranged between the substrate layer 103 and the circuit board 101. This connecting layer 102 is, for example, an adhesive layer. The adhesive layer is, for example, a double-sided adhesive film. The adhesive layer extends along the entire surface of the substrate layer 103, so that the substrate layer 103 is completely adhered to the circuit board. Furthermore, the connecting layer 102 has recesses 111, each of which is assigned to a recess 105 of the circuit board 101. Thus, the connecting layer 102 has Figure 132 recesses, each of which, together with a recess 105 in the circuit board 101 and the substrate layer 103, forms a sample chamber. In other words, the sample chamber extends through the circuit board 101 and through the connecting layer 102 to the substrate layer 103. Furthermore, the connecting layer 102 has holes or through-holes 112 for the electrical leads 106, which leads can extend through the circuit board 101 to the substrate layer 103 and thus also through the connecting layer 102. For each through-hole 108 and 107 in the circuit board 101, a corresponding through-hole 112 is provided in the connecting layer 102. The substrate layer 103 also has a plurality of leads to the electrodes 104. Furthermore, the circuit board has connections 109 and 110 for feeding in the electrical charge, in particular for feeding in alternating current.

[0049] Figure 2illustrates a sample carrier 200 according to another embodiment of the invention. The sample carrier 200 has the same configuration as the sample carrier in Figure 1Only the number of sample chambers and thus also the number of quadrupoles is different. The circuit board 101 of the sample carrier 200 comprises 40 recesses, each of which, together with the substrate layer 101 and the recesses 111 of the connecting layer 102, forms a sample chamber. Thus, there are 40 sample chambers in the sample carrier 200. Accordingly, 40 quadrupoles for electrical manipulation of the sample are formed on the substrate layer 103 by means of the electrodes 104a and 104b. The recesses are arranged in four groups, with each group being arranged in a 2 by 5 matrix. Each row is assigned a letter from A to D, and each column is assigned a number from 1 to 10. This allows the respective liquid sample to be assigned to the corresponding sample chamber. Thus, for example, the corresponding sample and sample chamber can be assigned from row a, line 3 during the vibrational spectroscopic analysis.Furthermore, connections 109 and 110 are provided for each group, allowing each group of sample chambers to be controlled differently with the associated electrodes 104. Depending on the circuit board 101 and substrate layer 103 configuration, the connection structure 102 has respective recesses 111 and through-holes 112 for the electrical leads 106.

[0050] Figure 3 illustrates a spectroscopic image of a recess 105 and thus a sample chamber containing a liquid sample 340. The sample 340 is trapped in the center of the sample chamber by dielectrophoresis, thus enabling vibrational spectroscopic analysis of the sample.

[0051] Figure 4illustrates a system 400 for vibrational spectroscopy according to an exemplary embodiment of the invention. The system 400 comprises a vibrational spectroscope 420 and a sample carrier 100 (200). Furthermore, the system comprises a detector 422 for vibrational spectroscopy, wherein the detector is arranged on one side of the sample carrier 100. The detector 422 is arranged on an underside of the sample carrier 100, i.e., the detector is arranged on the side of the substrate layer 103 and the spectrometer 420 is arranged on the side of the circuit board 101. In other words, the detector 422 is arranged on a side of the substrate layer 103 opposite the circuit board 101. In Figure 4In particular, 422 represents an objective turret to which various objectives are attached. The detector is arranged downstream of the objective turret and detects corresponding radiation through the selected objective. For example, in an inverse Raman spectroscope, both the detector and the spectroscope are arranged on the same side of the sample carrier 100, wherein the detector and the spectroscope are connected by means of the objective turret 422. In this embodiment, 420 represents a reflected light source, e.g., an LED, which can be used for morphological examinations. When using a reflected light source, a camera for the reflected light is additionally located on the side of the detector and the spectroscope.

[0052] The system further includes terminals 421 for supplying alternating current to the sample carrier. These terminals 421 are connected to terminals 109 and 110 of the sample carrier 100 via electrically conductive lines. The sample carrier 100 is held in the system by a sample carrier holder 423.

[0053] Figure 5 illustrates a duopole electrode arrangement, where Figure 5 the recess 105 with the liquid sample is shown. In the figure, the electrodes or the through holes 108 and 107 to the electrodes are shown circular. In the enlarged detail view in Figure 5 The sample 540 is shown inside the sample chamber. The sample chamber or the recess is shaped such that it can be Figure 5can be seen having 4 side arms, the four side arms forming a cross shape. In the duopole electrode arrangement, the electrodes 107 and 108 are not connected crosswise, i.e. two electrodes 107 of the same potential are arranged on one side of the recess 105 and two electrodes 108 of the other potential are arranged opposite them. With this electrode arrangement, the liquid sample 540 is not collected in the middle (as in a quadrupole arrangement), but in one or more of the four side arms of the sample chamber. Advantageously, more measuring points are obtained if the sample is distributed across the side arms. Furthermore, the duopole can be structurally arranged multiple times in a row without the need for more supply lines. This again increases the number of measuring points.

[0054] Figure 6illustrates a duopole electrode arrangement, with two electrodes 104b for supplying positive charge and one electrode 104a for supplying negative charge. Furthermore, Figure 6 the connections of the electrodes 104 to each other are shown. The electrodes of the same potential, ie electrodes 104a and electrodes 104b, are interconnected by means of electrode connections 660. Thus, the same potential is applied to several electrodes 104a, 104b simultaneously. In the enlarged detailed illustration in Figure 6 It is illustrated that the electrode leads run directly next to each other, but do not cross each other. Furthermore, the enlarged detail in Figure 6 3Duopole structures, each with two measuring points. When the sample is placed in the recess, the bacteria in the sample are evenly distributed in the liquid sample by the duopole arrangement. The applied electric field deflects the bacteria as they sink to the bottom of the sample chamber and (in this case, with the duopole) are trapped in the side arms. With the quadrupole, the bacteria are trapped in the center. Advantageously, the areas between the duopole regions are V-shaped, thus aligning the field lines in such a way that the trapping of bacteria in the side arms is improved. Furthermore, the individual duopole structures are spaced apart from one another to prevent mutual interference, such as mutual trapping of the bacteria.

[0055] Figure 7illustrates a pin array 731 according to an exemplary embodiment of the connection, wherein the pin array 731 is provided for electronically contacting the electrodes 104. The pin array 731 can be formed by means of a separate chip or a separate circuit board. Electrical pins 730, in particular spring contact pins, spring contact pins, or pogo pins, are used for contacting. The contact can be created by the pins 730 electrically connecting the circuit board 101 and the substrate layer 103; in this case, the conductive paste can be omitted. The pin array 731 can be arranged as an additional element on the sample carrier 100 or 200.

[0056] Additionally, it should be noted that "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. List of reference symbols

[0057] 100, 200 Sample carrier 101 Printed circuit board 102 Interconnect layer 103 Substrate 104 Electrodes (104a, 104b) 105 Circuit board cutouts 106 Leads 107 Through-hole 108 Through-hole 109 Connector 110 Connector 111 Interconnect layer cutout 112 Through-hole 113 First main surface 340 Sample 400 System 420 Vibrational spectroscope 421 Connector 422 Detector 423 Sample carrier holder 540 Sample 660 Electrode connection 730 Connection pins 731 Pin array

Claims

1. A sample carrier (100) for electrical manipulation of liquid samples and for vibrational spectroscopy of the samples, the sample carrier comprising a substrate layer (103), a printed circuit board (101), wherein the printed circuit board is arranged on the substrate layer, wherein the substrate layer comprises a plurality of electrodes (104) for electrical manipulation of liquid samples, wherein the printed circuit board (101) comprises electrical leads (106) to the electrodes of the substrate layer, and wherein the printed circuit board comprises a plurality of recesses (105), each of which, together with the substrate layer (103), forms a sample chamber, wherein the electrodes are configured to generate an inhomogeneous electric field for dielectrophoresis.

2. Sample carrier according to claim 1, wherein the electrodes (104) of the substrate layer (103) are arranged at least partially one above the other, wherein in particular an insulating layer is arranged between the electrodes (104) arranged one above the other to insulate the electrodes from one another, and wherein, in particular, the electrical leads (106) are arranged at least partially on the substrate layer (103).

3. Sample carrier according to any one of the preceding claims, wherein the printed circuit board (101) comprises a first main surface (113) and a second main surface, wherein the first main surface (113) is arranged opposite the second main surface, and wherein the electrical leads (106) of the printed circuit board to the electrodes (104) of the substrate layer are arranged both on the first main surface (113) and on the second main surface.

4. Sample carrier according to any one of the preceding claims, wherein the substrate layer (103) is made of glass on or in which the electrodes (104) are arranged, wherein the glass is in particular a quartz glass.

5. Sample carrier according to any one of the preceding claims, wherein the electrodes (104) of the substrate layer (103) are designed as duopol, tripole, and / or quadrupole and for dielectrophoretic manipulation of the samples in the sample chambers.

6. Sample carrier according to claim 5, wherein one duopol, tripole or quadrupole of electrodes (104) is arranged on the substrate layer (103) per sample chamber.

7. Sample carrier according to any one of the preceding claims, wherein a volume of each sample chamber is in the range from 0.5 to 50 µl.

8. Sample carrier according to any one of the preceding claims, wherein a connection layer (102) is arranged between the printed circuit board (101) and the substrate layer (103).

9. Sample carrier according to claim 8, wherein the connection layer (102) is an adhesive layer, wherein the adhesive layer comprises recesses (111), wherein one recess (111) of the adhesive layer is arranged per recess (105) of the printed circuit board.

10. Sample carrier according to claim 9, wherein the recesses (111) of the adhesive layer each form a sample chamber together with a recess (105) of the printed circuit board (101) and the substrate layer (103).

11. Sample carrier according to one of the preceding claims, wherein the electrical leads (106) of the printed circuit board (101) extend at least partially through the printed circuit board.

12. Sample carrier according to claim 11, wherein the printed circuit board (101) comprises a plurality of through-holes (107, 108) for the electrical leads, wherein the electrical leads (106) extend through the through-holes to the electrodes (104) of the substrate layer (103).

13. A sample carrier according to any one of the preceding claims, wherein the electrical leads (106) do not overlap in a direction perpendicular to a layer direction of the substrate layer (103) and the printed circuit board (101) when the electrodes (104) are used as duopol, tripole, and / or quadrupole.

14. System (400) for vibrational spectroscopy comprising a vibrational spectroscope (420), in particular a Raman spectroscope and / or an infrared spectroscope, and a sample carrier according to claims 1 to 13.

15. A method of manufacturing a sample carrier (100) for electrical manipulation of liquid samples and for vibrational spectroscopy on the samples, the method comprising providing a substrate layer (103), applying a plurality of electrodes (104) for the electrical manipulation of liquid samples to the substrate layer, providing a printed circuit board (101), application of electrical leads (106) to the electrodes of the substrate layer on the printed circuit board (101), forming a plurality of recesses (105) on the printed circuit board, arranging the printed circuit board on the substrate layer, wherein the recesses (105) each form a sample chamber together with the substrate layer, wherein the electrodes are configured to generate an inhomogeneous electric field for dielectrophoresis.