A Portable Sensing System for Impedance based Detection of Biotoxin Substances

摘要

The study describes the development of a portable autonomous biosensing platform for impedance based detection of biotoxin substances. The platform implements a label-free approach, which is based on detection of the biosensor interfacial changes due to a bio recognition reaction. The interfacial changes are sensed by means of Electrochemical Impedance Spectroscopy in a frequency range from 10 Hz to 100 kHz. The platform comprises of an electrochemical biosensor, portable low-noise mix signal hardware and associated software incorporating signal processing algorithms for extraction biotarget concentration from the biosensor response. The biosensor is realized as an on-chip package-free three electrode micro electrochemical cell consisted of a counter electrode (CE), a reference electrode (RE) and a working electrode (WE) patterned on a single silicon chip. WE represents an array of 40 μm diameter gold disks with 400 μm center-to-center distance, which were undergone of corresponding surface modification for antibody immobilisation. The developed system was validated by an example of T-2 toxin detection. Performed calibration in the range of 0 - 250 ppm of T2 toxin concentrations confirmed that the system can provide successful detection of the toxin at the levels below 25 ppm.