4-Aminothiophenol-Modulated Ag Growth on Au Nanoparticles for Detection of Nitrite

Nitrite (NO2–) in water and food is a potential threat to human health. The determination of nitrite content is very significant for people’s life safety. Here, 4-aminothiophenol (4-ATP)-modulated silver growth on gold nanospheres (GNSs) was designed to detect nitrite. It was verified that the exposed amino groups of 4-ATP molecules on GNSs can accelerate Ag overgrowth. On the contrary, the deamination reaction of 4-ATP with nitrite can reduce the Ag overgrowth rates. 4-ATP modified on GNSs can not only increase the spectrophotometry response of nitrite with a low limit of detection (LOD = 36 nM) but also obtain a wide and flexible detection range (0–60 μM). In addition, this method showed good selectivity to nitrite. The excellent optical response, the sharp contrast between the acceleration and deceleration of Ag growth, and the customizable basic setting of the sensing ligands can provide a universal design scheme for high-performance detection methods.