Bioanalysis test kit and method for analyzing such a test kit

Abstract

The invention relates to a test kit which is designed for bioanalysis, in particular for an immunoassay. The test kit comprises at least one measuring sensor (M) for the quantitative detection of a substance and at least one reference sensor (R1, R2, R3) which is already supplied with the substance in a defined manner. In the method for analyzing a test kit, the measuring sensor (M) is read and a measurement value for a concentration, a substance quantity, or a mass is obtained, wherein the read value of the at least one measuring sensor (M) is scaled using the read values of the at least one reference sensor (R1, R2, R3), or a measured value which corresponds to the read value is obtained by means of a compensation curve which puts the read values of the reference sensors (R1, R2, R3) into relationship with the defined supply of the substance to the reference sensors (R1, R2, R3).

Claims

1. A test kit for bioanalysis, the test kit comprising: at least one measurement sensor coated with an antigen, an antibody, or the antigen and the antibody, such that the at least one measurement sensor is configured to quantitatively detect a substance via binding of the substance to the antigen, the antibody, or the antigen and the antibody; at least one reference sensor coated with the antigen, the antibody, or the antigen and the antibody, to which a defined concentration, amount, or mass of the substance is already bound, wherein the at least one reference sensor, the at least one measurement sensor, or the at least one reference sensor and the at least one measurement sensor are formed with acoustic resonators; and at least one reference compartment per reference sensor, the at least one reference sensor respectively being introduced therein, wherein the at least one reference compartment is separated from the measurement sensor in a fluid-tight manner during measurement.

2. The test kit of claim 1, wherein the at least one reference sensor comprises at least two reference sensors, the substance being supplied to a different extent to each of the at least two reference sensors.

3. The test kit of claim 1, further comprising: at least one measurement compartment per measurement sensor, the at least one measurement sensor respectively being introduced therein.

4. The test kit of claim 1, wherein the test kit is a pregnancy, drugs, or pregnancy and drugs test kit.

5. The test kit of claim 2, wherein the at least two reference sensors comprise three or more reference sensors, the substance being supplied to a different extent to each of the three or more reference sensors.

6. The test kit of claim 1, wherein the acoustic resonators are film bulk acoustic resonators.

7. The test kit of claim 1, wherein the at least one reference sensor is configured to implement a reference scale in the test kit.

8. The test kit of claim 1, wherein the at least one reference compartment is separated from the measurement sensor in a fluid-tight manner by a valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically shows a plan view of a test kit with a compartment with a measurement sensor formed with a plurality of acoustic resonators and with three compartments with one reference sensor each, the reference sensor being formed with a plurality of acoustic resonators, during the preparation for field use; and

(2) FIG. 2 schematically shows a plan view of the test kit according to FIG. 1 in the configuration during the field use.

DETAILED DESCRIPTION

(3) The test kit illustrated in FIG. 1 includes a sensor chip 10 that includes an array of acoustic resonators 20 in the form of film bulk acoustic resonators (FBARs). In a manner known per se, such acoustic resonators 20 may be used to detect the attachment of substances from a detuning of the resonant frequency. In the case illustrated in FIG. 1, 16 resonators form a sensor in each case. Here, three of such sensors formed by groups of resonators respectively form a reference sensor R1, R2, R3, and a fourth group forms the actual measurement sensor M.

(4) The reference sensors R1, R2, R3 and the measurement sensor M are separated from one another in a fluid-tight manner in each case by virtue of biocompatible compartments, formed with PBO, for example, being deposited on the chip surface by a wafer level process in a manner known per se. Each of the reference sensors R1, R2, R3 and the measurement sensor M are arranged in a single compartment in each case. A flow cell manufactured from PEEK by an injection molding is attached thereto in each case in a fluid-tight manner.

(5) Initially, the test kit is prepared for field use as follows (e.g., by the producer after production of the test kit in the illustrated case).

(6) Initially, the acoustic resonators 20 are functionalized. To this end, each compartment of the reference sensors R1, R2, R3 and of the measurement sensor M are attached to a fluid feed F via the respectively assigned flow cell. Initially, an assay-compatible buffer solution, a phosphate-buffered saline (PBS) in the illustrated exemplary embodiment, is supplied to each inlet E of the respective fluid feed F. Each compartment of the respective reference sensor R1, R2, R3 and of the measurement sensor M is rinsed by this buffer solution.

(7) Subsequently, both the resonators 20 of the reference sensors R1, R2, R3 and the resonators 20 of the measurement sensor M are functionalized (e.g., coated on the surface) with a catcher antibody.

(8) After another rinse step for each compartment of the respective reference sensor R1, R2, R3 and of the measurement sensor M, non-specific attachment surfaces of the sensor chip 10 (e.g., areas that do not form any functionalized areas of the resonators 20) are passivated. Albumin (hsa/bsa) is added in each case via the inlet E of the respective fluid supply F.

(9) After another rinsing step for each compartment of the respective reference sensor R1, R2, R3 and of the measurement sensor M, a defined concentration of the target substance is respectively supplied to each compartment of the reference sensors R1, R2, R3 (but not to the compartment of the measurement sensor M). A different concentration of the target substance is supplied to each of the reference sensors R1, R2, R3. Subsequently, the compartments assigned to the reference sensors R1, R2, R3 and the compartment assigned to the measurement sensor M are filled with a suitable amount of preserving solution. Consequently, the sensor chip 10 may be stored until the intended field use.

(10) In further exemplary embodiments without a dedicated illustration, additional compartments with further measurement and reference sensors are present. The additional compartments serve to measure further substances. In principle, the resonators may be functionalized by micro-spotters in further exemplary embodiments that are not presented separately below and not explained in detail here, and so, for example, individual resonators within one compartment may be functionalized for substances that differ from one another.

(11) For field use, the feeds F with corresponding inlets E are connected to a distributor V that has a common inlet G. Further, the feed F feeding the measurement sensor is provided with a 3-way valve 30, by which either the distributor V or a sample inlet S is fluid-connectable to the compartment of the measurement sensor M. Initially, the sensor chip 10 is activated during field use by virtue of the compartments of the reference sensors R1, R2, R3 and of the measurement sensor M initially being rinsed with buffer solution. Consequently, the preserving solution is completely removed.

(12) The measurement sensor M is fluidically decoupled by setting the 3-way valve 30, and the target substance is supplied to the measurement sensor M by the sample inlet S. The target substance is thus supplied to the measurement sensor M. The compartments assigned to the reference sensors R1, R2, R3 continue to be rinsed with the buffer solution.

(13) Subsequently, the antigen complex fitting to the catcher antibody is supplied to all compartments of the reference sensors R1, R2, R3 and of the measurement sensor M.

(14) Subsequently, and for the measurement, all chambers are then rinsed again with a buffer, both simultaneously and with the same flow, and the measurement of the displacement of the resonant frequency of the FBARs is carried out.

(15) Subsequently, the measurement values of the sensor chip 10 are evaluated. The corresponding to the preceding defined supply of the reference sensors R1, R2, R3 are related to the readout values of the reference sensors R1, R2, R3. Consequently, in the illustrated exemplary embodiment, the concentrations of the target substance, supplied to the reference sensors R1, R2 and R3 when preparing the sensor chip 10, are related to the frequency shift of the resonant frequency of the acoustic resonators 20 of the respective reference sensors R1, R2 and R3. The relationship, which is linear to very good approximation, is mapped using a compensation straight line. A frequency shift of the measurement sensor M may thus be converted into concentration of the target substance using the compensation straight line.

(16) In a further exemplary embodiment, which corresponds to the exemplary embodiment explained above, the supply of a reference sensor R1, R2, R3 is selected to have a concentration that corresponds to a limit value that is of importance, for example, for driving a vehicle, operating a machine or any other legal constraint. If the frequency shift of the measurement sensor M is compared to the frequency shift of this reference sensor, it is possible to directly deduce a concentration of the target substance above the limit value.

(17) The details of the functionalization of the compartments may remain hidden in the exemplary embodiments explained above. Consequently, a manipulation of the sensor chip 10 is effectively prevented, or else a manipulation may easily be detected.

(18) The elements and features recited in the appended claims may be combined in different ways to produce new claims that likewise fall within the scope of the present invention. Thus, whereas the dependent claims appended below depend from only a single independent or dependent claim, it is to be understood that these dependent claims may, alternatively, be made to depend in the alternative from any preceding or following claim, whether independent or dependent. Such new combinations are to be understood as forming a part of the present specification.

(19) While the present invention has been described above by reference to various embodiments, it should be understood that many changes and modifications can be made to the described embodiments. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting, and that it be understood that all equivalents and/or combinations of embodiments are intended to be included in this description.