Dynamic reaction regulated surface-enhanced Raman scattering for detection of trace formaldehyde.

A simple and reliable method was developed by combining redox reaction with surface-enhanced Raman scattering (SERS) for the indirect detection of formaldehyde (FA). Silver nanoparticles (AgNPs) can be generated from the reaction between the silver ammonia solution containing silver nanoclusters (AgNCs@Tollens) and FA, which can improve the SERS signal of rhodamine 6G (R6G). The detection principle was based on the enhancement of the SERS signal of R6G caused by the increase in the intensity of localized surface plasmon resonance (LSPR) upon the reduction of AgNCs@Tollens by FA. This method exhibits high sensitivity and selectivity for the detection of FA with a linear range from 5 μM to 160 μM and a limit of detection (LOD) of 2.5 μM. The proposed method was successfully used for the detection of FA released from furniture panels with a recovery rate of 95-100%.