A novel dual-response fluorescence probe (XBT-CN) was developed by using a fluorescence priming strategy for quantitative monitoring and visualization of hydrazine (N₂H₄) and hypochlorite (ClO⁻). With the addition of N₂H₄/ClO⁻, the cleavage reaction of C=C bond initiated by N₂H₄/ClO⁻ was transformed into corresponding hydrazone and aldehyde derivatives, inducing the probe XBT-CN appeared a fluorescence “off-on” response, which was verified by DFT calculation. HRMS spectra were also conducted to confirm the sensitive mechanism of XBT-CN to N₂H₄ and ClO⁻. The probe XBT-CN had an obvious fluorescence response to N₂H₄ and ClO⁻, which caused a significant color change in unprotected eyes. In addition, the detection limits of XBT-CN for N₂H₄ and ClO⁻ were 27 nM and 34 nM, respectively. Interference tests showed that other competitive analytes could hardly interfere with the detection of N₂H₄ and ClO⁻ in a complex environment. In order to realize the point-of-care detection of N₂H₄ and ClO⁻, an XBT-CN@hydrogel test kit combined with a portable smartphone was developed. Furthermore, the portable test kit has been applied to the detection of N₂H₄ and ClO⁻ in a real-world environment and food samples, and a series of good results have been achieved. Attractively, we demonstrated that XBT-CN@hydrogel was successfully applied as an encryption ink in the field of information security. Finally, the probe can also be used to monitor and distinguish N₂H₄ and ClO⁻ in living cells, exhibiting excellent biocompatibility and low cytotoxicity.

We described the design, synthesis and antimicrobial activities of novel pleuromutilin derivatives with substituted piperazine substrate. Minimum inhibitory concentration (MIC) was used to evaluate the activity of the derivatives against six bacteria in vitro, and compound 8 was potent against Staphylococcus aureus and Staphylococcus epidermidis with the MIC value of 0.0625 μg/ml. 10a and 10 b showed similar activity to positive control drugs (tiamulin, erythromycin) against S. aureus with the MIC value of 0.125 μg/ml. The binding mode of compound 8 and tiamulin to the ribosome pocket showed the correlation between binding parameters and the antibacterial activity, and more bonds and stronger combination could effectively enhance the activity of compounds. Graphical Abstract