Novel molecule design for surface modification enables highly selective DMMP detection with silicon nanoribbon FET sensors

Abstract

Sarin is a highly toxic nerve agent, and the potential threat of its misuse has driven extensive research into detecting its simulant, DMMP. Although silicon-based FET gas sensors offer advantages such as rapid response, high sensitivity, and compatibility with semiconductor processing, their use in DMMP detection remains limited. This is primarily due to the absence of effective modification molecules that can provide silicon materials with selective recognition capability for DMMP. Here, a novel molecule, HFIPPUT, incorporating terminal hexafluoroisopropanol (HFIP) and siloxane groups, is designed and synthesized. The HFIPPUT molecules are modified onto the surface of silicon nanoribbon (SiNR) FET devices through chemical bonding. The HFIP groups in the modified molecules facilitate highly selective and sensitive detection of DMMP by forming strong hydrogen bonds with the phosphoryl oxygen in DMMP molecules. The resulting HFIPPUT-SiNR FET gas sensor demonstrates a remarkable and rapid response to DMMP vapor across concentrations of 1–100 ppm at room temperature. Notably, the sensor exhibits exceptional selectivity for DMMP, outperforming other Si-based FET gas sensors. The results confirm the effectiveness of the molecular design strategy, enabling highly selective DMMP detection with Si-based FET devices and paving the way for using mature semiconductor processing technologies in detecting chemical warfare agents.