Nanowire Sensors Using an Electrical Resonance Approach for Vapor Detection

Abstract

Recent advances in our understanding of 1D nanomaterials are paving the way for developing novel platforms for sensors and devices based on multi-physics, multi-modal approaches. Here, we report a new way of detecting volatile organic compounds (VOC) using electrical resonance of a single platinum nanowire. The adsorption of molecular dipoles on a nanowire causes a measurable change in the dissipation and frequency of the electrical resonance. The dissipation at the resonance shows enhanced variations depending on the dipole moments of the adsorbates. Experimental results show the limit of detection (LOD) for sensing acetone, methanol, and ethanol by a nanowire sensor in the range of a few ppm. The LOD, however, can be improved by optimizing the electrical parameters of the nanowire. Furthermore, monitoring the dissipation variations at resonance as a function of temperature provides information on thermally induced polarization or depolarization of adsorbed chemical species. The temperature response of the nanowire at resonance could potentially be used to discriminate different vapor molecules based on differential calorimetry.