Miniaturised biosensor with optimized amperometric detection

Abstract

A method to optimize the amperometric detection in a microsystem consists in limiting the detection to times when the diffusion layer (18-20) of the analyte to detect remains smaller than the microchannel (7) height. The charge detected during the second part of the amperometric measurement (which corresponds to the integral of the measured current over the corresponding time period) can also be considered so as to remove the contribution of the capacitive current and, when applicable, of the current resulting from the reduction or oxidation of the analyte molecules present in a recess above the electrode at the beginning of the detection. A microfluidic amperometric sensor for performing the method comprises at least one microchannel (7) having at least one electrode (15-17), integrated in one wall of the microchannel, and having a characteristic length or radius which is smaller than half the microchannel height.

Description

field of invention [0001] This invention relates to amperometric sensors for the analysis and detection of biological and chemical compounds in small volume samples and methods of making and using such sensors. Background of the invention [0002] The miniaturization of analytical instruments has become very attractive in the field of analytical chemistry mainly for two different reasons, namely the reduction of the time required for each analysis and the reduction of sample and reagent volumes and the amount of waste. In recent years, many advances have been made in fabricating microfluidic devices and using them to develop various types of assays. [0003] One of the bottlenecks in miniaturization is to ensure the lower limit of detection despite the small volume of microfluidic devices and thus the low number of molecules present in these systems. Different detection methods have been successfully implemented, including optical, mass spectrometric, or electrochemical det...

AI Technical Summary

Problems solved by technology

The overall profile of the concentration evolves due to the depletion of the electroactive species at the electrodes, resulting in a weakening of the solution (current) and consequently a decrease in the measurable current

This limits the detection sensitivity and it is therefore an object of the present invention to provide electrochemical microsensors and methods capable of detecting the highest possible current by optimizing the geometry of the microsystem and / or the amperometric detection method

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