Intrinsic self-calibration electrostatic-controlled ratiometric fluorescence assay of histamine in human serum and canned tuna fish samples

Bimetallic nanoclusters protected by proteins have gained significant attention in the sensing field due to their aggregation-induced emission (AIE) property. However, their applications may be restricted by the effects of temperature, pH, ethanol, and metal ions. Therefore, the development of self-assembling technology could increase the potential applications of these materials. In this study, positively charged silicon nanoparticles (SiNPs) were mixed with negatively charged bovine serum albumin-protected silver doped gold nanoclusters (BSA@AgAuNCs) through an electrostatic interaction. The resulting system exhibited dual emissions at 610 nm ((BSA@AgAuNCs) and 460 nm (SiNPs) when excited at 370 nm. The mixing of SiNPs led to an increase in the fluorescence emission of BSA@AgAuNCs due to an aggregation-induced emission (AIE) enhancement. However, the addition of histamine, which is positively charged at pH 5.5, caused the SiNPs to be triggered and adsorbed onto the surface of BSA@AgAuNCs, resulting in their disaggregation and a decrease in their fluorescence emission. Simultaneously, the blue fluorescence emission of SiNPs at 460 nm was not affected and remained unchanged. Under optimized conditions, the fluorescence response (F460/F610) showed a linear increase with the concentration of histamine in the range of 0.01-80 mu M, with a detection limit (S/N = 3) of 3.0 nM. The probe demonstrated excellent sensitivity, selectivity, and reliability in quantifying histamine in complex matrices. The recoveries % values are in the range of 97-102% and 97.7-104.4% with RSD % in the range of 2.67-3.98% and 2.78-4.00% for human blood serum and canned tuna fish samples, respectively. This work presents new opportunities for the development of sensors based on self-assembling and dual emissive properties for (bio) sensing applications.