Actuating Gold Nanoparticle Chemiresistor Sensitivity and Selectivity for Sensing Carbonyl Compounds in Air

Poor sensitivity and selectivity are common challenges faced by gas sensing chemiresistors. This work demonstrates a new approach that uses designed thiol monolayers to functionalize gold nanoparticles (AuNPs) for sensing trace volatile carbonyl compounds. A thiol ligand fitted with a -urea group for molecular recognition of carbonyls dramatically increases both the sensitivity and selectivity of the derived AuNP sensor. The sensitivity for acetone detection surpasses all current chemiresistor limits of detection. The sensor works under ambient temperature and low humidity conditions, and shows a linear relationship between response and a broad carbonyl analyte concentration range of 0.1 ppb to 1000 ppm.