An Aminobenzenethiol-Functionalized Gold Nanocolorimetric Sensor for Formaldehyde Detection.

The determination of formaldehyde is of paramount importance, as it is present in numerous locations throughout life. In this study, aminophenol-modified gold nanoparticles (ATP-AuNPs) with different relative positions of hydroxyl and amino groups were synthesized for the detection of formaldehyde. They were characterized by transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectroscopy and Fourier transform infrared (FTIR) spectroscopy tests. The results demonstrated that the position plays a crucial role in the composites, which exhibit good stability when the sulfhydryl group and amino group transition from the para position to the neighboring position. Furthermore, the para position was identified as the optimal configuration for formaldehyde detection. When it was used to detect formaldehyde in ultrapure and Li River water, the limit of detection (LOD) was calculated to be 1.03/1.15 mM, respectively. This work not only provides a novel ATP-AuNP sensor but also highlights its practical situations.