A Dual Fluorometric and Colorimetric Sulfide Sensor Based on Coordinating Self-Assembled Nanorods: Applicable for Monitoring Meat Spoilage

Psychrotrophic bacteria, commonly called spoilage bacteria, can produce highly toxic hydrogen sulfide (H2S) in meat products. Thus, monitoring the presence of hydrogen sulfide in meat samples is crucial for food safety and storage. Here, we report a unique chemical sensor based on supramolecular nanorods synthesized via copper ion induced self-assembly of N,N-bis[aspartic potassium salt]-3,4,9,10-perylenetetracarboxylic diimide (APBI-K). The self-assembled nanorods can specifically detect sulfide with a detection limit of 0.181 mu M in solution. The nanorods suspended in pure water show a turn-on fluorescence sensing behavior along with color change, acting as a dual fluorometric and colorimetric sensor. Spectroscopic investigation confirms the sensing mechanism due to copper ion displacement induced by the association with sulfide. Based on the high selectivity and sensitivity, supramolecular nanorod sensors were successfully employed to detect H2S in spoiled meat sample as well as dissolved H2S in water.