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 MnO 2 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 (λ emi : 553 nm) as an energy donor and MnO 2 nanosheets as the energy acceptor. As BAs exist, diamine oxidase will catalyze BAs to generate hydrogen peroxide (H 2 O 2 ), which can reduce MnO 2 to Mn 2+ , resulting with the dissociation of MnO 2 nanosheets and the signal recovery of R6G. Under optimal conditions, the analytical method obtained a wide linear detection range of 10 ∼ 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.