A Novel Microcantilever Device with Nano-Interdigitated Electrodes (Nano-IDEs) for Biosensing Applications

Abstract

We present a novel microcantilever device with nano-interdigitated electrodes (nano-IDEs) and selective functionalization of nano-IDEs for biosensing applications. The nano-IDEs play a role in precisely addressing capture molecules to a specific region on a microcantilever. This leads to a detectable surface stress due to the binding of target molecules. 70~500 nm-wide gold (Au) nano- IDEs are fabricated on a low-stress SiNx microcantilever with dimensions of 100~600 μm in length, and 15~60 μm in width, with a 0.5 μm thickness using electron beam lithography and bulk micromachining. 32~96 nm-thick streptavidin is selectively deposited on one side of nano-IDEs using cyclic voltammetry at a scan rate of 0.1 V/s with a range of -0.2~0.7 V during 1~5 cycles. The selective deposition of streptavidin is confirmed by fluorescence microscopy and atomic force microscopy (AFM).