The construction and destruction of gold nanoparticle assembly at liquid-liquid interface for Cd sensing.

The analyte-induced aggregation of plasmonic nanoparticles (NPs) in the bulk solution have been widely employed in optical sensors. However, in trace detection, the slow diffusion kinetics of NPs and the ultralow concentration of analytes significantly limit the binding opportunity of the analytes, thus impose penalties on the sensitivity, reproducibility and response time of the sensors. Herein, we propose a novel sensing method with two working modes that based on the construction/destruction of NP arrays at the liquid-liquid interface (LLI).