Biosensor Instrumentation with attoFarad Resolution for Electrochemical Impedance Measurements at the Nanoscale

Keywords:
attinity biosensors, biomolecular detection, low noise, electrochemical impedance spectroscopy

Abstract:
A complete potentiostatic measurements systems and a single-chip front-end for detection of sub-pA currents are presented here. This instrumentation is aimed at the realization of affinity biosensors by means of impedimetric detection of conformational changes of the bio-macromolecules complexes binding to target analytes. Both implementations are based on an innovative integrator / differentiator topology which enables the achievements of ultra low noise sensitivity (7 e 3 fA/sqrt(Hz) respectively) over a continuous wide bandwidth (DC – 1MHz). The potentiostat system allows performing cyclic voltammetry, electrochemical impedance spectroscopy and impedance tracking in time domain on interfacial systems whose dimensions can range from millimetric down to sub-micrometric scale, with a resolution of tens of aF’s. Along with instrumentation design, the results of its thorough experimental characterization are illustrated.

Nanotech 2008 Conference Program Abstract