Method and device for determining a concentration of ligands in an analysed sample

• US 20050239132A1
• Filed: 04/11/2003
• Published: 10/27/2005
• Est. Priority Date: 11/05/2002
• Status: Active Grant

• Current Assignee: Endress+Hauser Conducta Gesellschaft FUER Mess- und Regeltechnik mbH+Company KG (Endress+Hauser AG)
• Original Assignee: Endress+Hauser Conducta Gesellschaft FUER Mess- und Regeltechnik mbH+Company KG (Endress+Hauser AG)
• Inventors: Klapproth, Holger
• Granted Patent: US 8,685,644 B2
• Time in Patent Office: Days
• US Class Current: 435/7.100
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: G01N 2035/00158 Elements containing microarrays, i.e. "biochip"
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings

Abstract

The invention relates to a method for determining a concentration of ligands in an analyzed sample. The inventive method consists in immobilizing receptors specifically boundable with said ligands on a support. At least one measured value of the occupation of the support surface by the receptors is determined by means of a sensor for the surface occupation. Afterwards, the sample is put in contact with the receptors. At least one measured value of the frequency of liaisons between the ligands and the receptors is determined by means of at least one detector. The concentration of ligands in the sample can be determined with the aid of the measured values of the occupation of the surface and frequency of ligands/receptors liaisons.

Claims

1. Method for the determination of the concentration of ligands contained in a sample to be analyzed, whereby receptors that can enter into a specific bond with the ligands are immobilized on a support, whereby the sample is brought into contact with the receptors, whereby at least one measurement value representing the frequency of the bonds between the ligands and the receptors is measured, and on the basis of this measurement value the concentration of the ligands in the sample is determined, characterized by the fact that at least one measurement value of the surface occupation of the surface of the support with the receptors is determined, and that the concentration of the ligands is determined by means of the measurement values for the surface occupation and the frequency of the bonds.

2. Method as claimed in claim 1, characterized by the fact that the receptors are not bonded to ligands during the measurement of the surface occupation, and that the sample is brought into contact with the receptors, after the surface occupation of the surface of the support with the receptors has been determined.

3. Method as claimed in claim 1, characterized by the fact that after the immobilization of the receptors on the surface of the support, for the determination of the measurement value for the surface occupation, the electrical impedance is measured on the surface of the support, and that then the sample is brought into contact with the receptors and the at least one measurement value for the frequency of the bonds is determined.

4. Method as claimed in claim 1, characterized by the fact that after the immobilization of the receptors on the surface of the support for the determination of the measurement value for the surface occupation, the electrical field strength on the surface of the support is measured, and that then the sample is brought into contact with the receptors and the at least one measurement value for the frequency of the bonds is determined.

5. Device for the determination of the concentration of ligands contained in a sample to be analyzed, with a support on the surface of which receptors are immobilized which, when they come into contact with the ligands can enter into a specific bond with the ligands, and with at least one detector for the determination of at least one measurement value that represents the frequency of the ligand-receptor bonds, characterized by the fact that the device has at least one surface occupation sensor for the measurement of the surface occupation of the surface of the support with the receptors, and that the surface occupation sensor and the detector for the determination of the concentration of the ligand in the sample are connected with an evaluation device.

6. Device as claimed in claim 5, characterized by the fact that the at least one surface occupation sensor is an impedance sensor.

7. Device as claimed in claim 5, characterized by the fact that the at least one surface occupation sensor is a field effect transistor, and that the support preferably has a semiconductor substrate, into which the field effect transistor is integrated.

8. Device as claimed in claim 5, characterized by the fact that it has at least one optical radiation source for the excitation of the emission of luminescent radiation as a function of the bonding of the ligand to the receptors, in the radiation range of which the receptors are located, and that the at least one detector is realized for the determination of the luminescent radiation in the form of a radiation receiver, which is preferably integrated into the semiconductor substrate of the support.

9. Device as claimed in claim 5, characterized by the fact that a plurality of detectors are integrated in a matrix pattern into the semiconductor substrate, and that a plurality of surface occupation sensors are distributed over this matrix, preferably between the detectors.