Optimization of reusable polysilicon nanowire sensor for salt concentration measurement

Abstract

Using a top-down technique, we fabricate reusable poly-Si nanowire sensors of various lengths for measuring salt concentration. The threshold voltage and resolution of these sensors correlate well with the nanowire length. Experimental results indicate that although the threshold voltage and resolution are proportional to the nanowire length, the sensitivity is inversely proportional to the length. Additionally, the smallest threshold voltage and the best resolution are 1.65 V and 0.023 ppm, respectively. Moreover, the proposed sensor can be reused more than 60 times with an acceptable performance. On the basis of these findings, we can conclude that the poly-Si nanowire sensor is applicable to biochemical detection with appropriate surface modification of the nanowire.