Turn on fluorescent detection of biogenic amines in fish based on MnO2-coated and rhodamine 6G-loaded mesoporous silica nanospheres

Biogenic amines (BAs) in fish or fish products may render the food toxic, which allow to be used as an indication for microbial spoilage. Thus, it is crucial to construct a rapid and sensitive analytical method for detection of BAs. In this work, based on rhodamine 6G-loaded and MnO2 nanosheets-coated mesoporous silica nanospheres (MSNs), a highly sensitive fluorescence probe was designed and developed. Wherein, a signal on fluorescence was achieved by using R6G (lambda(emi): 553 nm) as an energy donor and MnO2 nanosheets as the energy acceptor. As BAs exist, diamine oxidase will catalyze BAs to generate hydrogen peroxide (H2O2), which can reduce MnO2 to Mn2+, resulting with the dissociation of MnO2 nanosheets and the signal recovery of R6G. Under optimal conditions, the analytical method obtained a wide linear detection range of 10 similar to 400 nM with a detection limit of 5.97 nM (S/N = 3, n = 3). As a proof-of-application study, the analytical method was verified by spiked fish samples with recoveries of 93.97 to 101.57 % and was accurate at 95 % confidence level, indicating its good performance in detection of BAs and promising applications in food safety.

Automated summary

A highly sensitive fluorescence probe based on rhodamine 6G-loaded and MnO2 nanosheets-coated mesoporous silica nanospheres was developed for the detection of biogenic amines (BAs) in fish or fish products. The probe utilized R6G as an energy donor and MnO2 nanosheets as an energy acceptor. The method showed a wide linear detection range and high sensitivity, and was successfully validated using spiked fish samples, demonstrating its potential application in food safety.