A novel AIE peptide-based fluorescent probe for highly selective detection of mercury(II) ions and its application in food samples and cell imaging

A novel peptide-based fluorescent probe TPE-PGH was firstly developed based on aggregation-induced emission (AIE) effect. The fluorescence intensity of TPE-PGH was largely ignored in the low water fraction, whereas bright blue fluorescence was observed in the high water fraction. TPE-PGH achieved high selectivity and rapid detection of Hg2+, and has excellent sensitivity to detect Hg2+ with low LOD (58.1 nM). Interestingly, TPE-PGH provided a significant color changed from dark blue to bright cyan upon binding with Hg2+ ions under UV lamp (365 nm). In addition, TPE-PGH was able to simultaneously visualize Hg2+ in living cells with different fluorescence intensities based on excellent cells permeability and low toxicity. Further, TPE-PGH exhibited high precision (RSD < 4 %), and was successfully applied for detecting Hg2+ in real food samples, such as milk, soda drink, red wine, cucumber, tomato and carrot. Successful test strips responses also demonstrated that the potential of TPE-PGH for portable detection of Hg2+ in real samples. Especially, AIE based-test strips soaked in different Hg2+ concentrations was successfully utilized for semi-quantitative detection of Hg2+ using the RGB APP installed on a smartphone, which will provide a new approach for smart and portable detection of contaminated heavy metal ions in food samples.