Method for improving the measurement accuracy of sensors, especially bio-sensors, which are used to determine the signals of fluorescence radiation

• US 20030157726A1
• Filed: 02/21/2002
• Published: 08/21/2003
• Est. Priority Date: 08/31/2000
• Status: Active Grant

• Current Assignee: PES Gesellschaft FUER Medizinische Diagnosesysteme mbH
• Original Assignee: PES Gesellschaft FUER Medizinische Diagnosesysteme mbH
• Inventors: Drobner, Franz, Blum, Uwe, Boll, Peter
• Granted Patent: US 6,656,742 B2
• Time in Patent Office: Days
• US Class Current: 436/172
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/648 using evanescent coupling or surface plasmon coupling for the excitation of fluorescence
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 2201/127 Calibration; base line adjustment; drift compensation
• CPC Class Codes: G01N 2201/12753 and storage
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing

Abstract

Fluorescing reference material is used for calibration purposes for improving the measurement accuracy of sensors, especially biosensors, which use fluorescence radiation for determination of signals, the sensors each comprising a waveguide having at least one wave propagation surface as assay, a reactant being supported on the reactant comprising a species of molecule and being bound to an analytical material within a test medium, the waveguide transmitting an output emission radiation signal when it receives a radiation access signal.

Claims

1. Method for improving the measurement accuracy of sensors, especially of biosensors, which use fluorescence radiation for the determination of the signals, comprising a waveguide with at least one wave propagation surface as assay, which contains a reactant, which consists of a species of molecule, which is bound to an analytical material within test medium, and consists of a fluorescing reference material, which is used for the calibration, the waveguide transmitting an output emission radiation signal when it receives a radiation access signal, wherein

at each sensor of a batch, a fluorescence standards strip is affixed as reference material, this strip being disposed at the sensor next to the assay or spatially separated therefrom

subsequently, for each affixed fluorescence standard strip (FS) of the sensor batch, the fluorescence signal (I_FS) is measured by means of a process fluorimeter and a correction factor (α

) of the fluorescence signal (I_FS) related to a nominal batch value (I_o), is formed for each sensor;

α

=I_FS/I_o

the internal correction value α

of the sensor is written on a data storage medium, which is affixed to each sensor, or filed in an appropriate data base;

subsequently, the assay is calibrated, sensors being taken at random from a batch of sensors and measured with calibrators with known concentrations of analyte, in order to determine the fluorescence signals as a function of the analyte concentration for each assay (J_Assey)

subsequently, the correction value α

is read from each data storage medium of the sensors or taken from the database and a ratio β

of the fluorescence intensity of the assay (J_Assay) to that of the fluorescence standards strip (J_FS) is formed

β

=α

(J_Assay/J_FS)

a calibration curve f(c) of the sensor is determined from the ratio β

for the individual analyte concentrations of each individual sensor of the batch and affixed to the sensor as information or read into a database,

for the measurement of an analyte concentration (c) of an unknown sample, the measured fluorescence signals from the assay (J′

_Assay) and from the fluorescence standards strip (J′

_FS) are related to one another and multiplied by the correction value α

of the sensor, in order to obtain the ratio β

, in order to determine the concentration of analyte (C) of the unknown sample from the magnitude of β and

of the lot-specific calibration curve f(c) enclosed with the sensor.