Fabrication, Calibration, and Recovery of Chemical Nanosensor Array for Ammonia Detection

Abstract

The low selectivity of nanosensors is one of their major obstacles for their wide deployment. To enhance the selectivity, nanosensor array made from zinc oxide (ZnO) nanowires and carbon nanotubes (CNTs) was assembled through dielectrophoresis (DEP). The fabricated nanosensor array was used to detect ammonia (NH3) in a well-controlled environment at room temperature. Because of their opposite material types, ZnO nanowire based sensor behaved oppositely to CNT based sensor. In this study, it is also demonstrated that DC biases can quickly recover both sensing elements. After collecting sensing signals from two transducers under different NH3 concentrations, the concentration of NH3 can be estimated through regression methods. It is shown that quadratic model with the lasso performs well on the collected data.