A novel dual-response chemosensor for bioimaging of Exogenous/Endogenous hypochlorite and hydrazine in living cells, Pseudomonas aeruginosa and zebrafish

Hypochlorite (ClO−) and hydrazine (N2H4) were poisonous to the biological environment. Accurate and sensitive identification of ClO− and N2H4 in biological and environmental systems was essential to reveal their various physiological and pathological functions. Herein, a dual-response chemosensor, HNTBA, was developed for quantitative monitoring and visualization of ClO− and N2H4 in vitro and in vivo via fluorescence turn-on strategy. With the addition of ClO−/N2H4, fluorescence “OFF–ON” response was obtained for the sensor as a result of specific ClO−/N2H4-triggered CC bond cleavage reaction with converted to the corresponding aldehyde and hydrazone, which responding mechanism was verified by DFT calculation. Additionally, HNTBA features rapid response (<30 s) and low limit of detection (nanomole), high sensitivity and selectivity toward ClO−/N2H4 over other analytes, which allow it to be used for quantification of ClO−/N2H4 in a simulated physiological condition. Fluorescence imaging using HNTBA sensor was taken to monitor the exogenous/endogenous ClO− levels in hPDLCs and RAW 264.7 cells in a concentration-dependent manner. Notably, HNTBA exhibits high effectiveness for early assessment of the treatment response of ClO−-mediated in cells with N-acetylcysteine (NAC) and lipopolysaccharide (LPS). Moreover, HNTBA can be used to visualize N2H4 in live cells from blue channels with good performance. The outstanding sensing performances of HNTBA sensor enabled fast tracking of ClO− and N2H4 in Pseudomonas aeruginosa and zebrafish with fluorescence light up, and it could be further applied to a paper strip. The results demonstrate that HNTBA was a powerful tool to monitor ClO− and N2H4 in biosystems and environmental.