INCREASING THE SENSITIVITY AND METROLOGICAL RELIABILITY OF A DIFFERENTIAL CONDUCTOMETRIC BIOSENSOR SYSTEM

Abstract

The differential method of conductometric measurements does not fully solve the problem of the influence of changes in the background electrical conductivity of the working buffer solutions on the results of conversion of the biosensor responses. The variation in the background electrical conductivity of the buffer solution upon addition of the highly conductive analyte acts as a common mode interference and causes the additive error. Here we present a new measurement method and structure of the device for quantification of the analytes that provide a significant decrease in the measurement error associated with a change in the background electrical conductivity caused by the introduction of the analyte to the working solution prior to the generation of the informative signal. A block diagram of the device and a vector model of the balancing process of its measuring circuit are presented. The advantages of the developed method and biosensor analyzer for application within the possible changes of the transducer parameters and measurement conditions are demonstrated. References 28, figures 4.

Keywords

• differential conductometric biosensors
• impedance
• measurement
• common mode interferences
• equivalent electrical model