A Reconfigurable and Portable Highly Sensitive Biosensor Platform for ISFET and Enzyme-Based Sensors

Abstract

This paper presents a portable low-cost biosensor platform for ion-sensitive field-effect transistor (ISFET) and enzyme-based sensors. To meet various demands of diagnosis, our portable platform is designed to perform cyclic voltammetry, amperometry, and linear sweep voltammetry for enzyme-based sensor and ISFET sensor. For compatibility with various sensors which require various electrical driving schemes, our system can be easily reconfigured by simple switches. In addition, with disposable printed-circuit-board packages, sensors can be easily replaced. Our platform was tested with various sensors in various measurement methods. In cyclic voltammetry test with a model analyte K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Fe(CN) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> , a graph provided by our system has 4.79% relative error at a current peak compared with the data acquired by a 18 times more expensive commercial system. In cyclic voltammetry and amperometry tests with the laccase enzyme-based sensors, our system achieved sensitivities of 341 and 500 μA/mM/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , respectively. By running a sensitive SiNW ISFET on our platform in linear sweep voltammetry, we could build a low-cost portable pH sensor system.