A near-infrared ratiometric fluorescent probe for simultaneous detection of hydrazine and hypochlorous acid in biological systems and its portable detection in environmental samples using a smartphone.

Hydrazine (NH) and hypochlorous acid (HClO) are significant chemicals that gain widespread applications in industrial fields. Excessive NH and HClO can cause severe environmental pollution and have toxic effects on living organisms. In this study, a near-infrared (NIR) dual-responsive fluorescent probe PTZ-BA was designed for the ratiometric detection of NH and HClO. PTZ-BA exhibited a remarkable near-infrared signal at 680 nm with a large Stokes shift of 275 nm, and it can simultaneously detect NH and HClO through different fluorescence channels without signal crosstalk. PTZ-BA possessed good selectivity, low detection limits, dramatic emission wavelength shift, short response time for the detection of NH and HClO. PTZ-BA could be employed for the quantitative analysis of NH and HClO in environmental soil and water samples, respectively. Furthermore, the functionalized nanofiber membranes and hydrogels were readily fabricated using this probe, enabling the portable on-site detection of gaseous NH and HClO with the help of smartphone. PTZ-BA could achieve the real-time tracking of NH and HClO in HeLa cells, onion cells and zebrafish. This research offers a versatile fluorescence detection platform for NH and HClO, holding a significant potential for environmental analysis and public health monitoring.