Recent Progress in Dual-Channel Probes for Zn ²⁺ Detection: Innovations in Bioimaging and Environmental Monitoring (2022-2025)

The detection of Zn²⁺ is of paramount importance due to its essential biological functions and significant environmental implications. Recent advances in fluorometric and colorimetric dual-channel sensors have markedly improved Zn²⁺ detection by achieving high selectivity, nanomolar-level sensitivity, and reliable signal output in complex matrices. Reported probes commonly exhibit low limits of detection, rapid response times, and strong discrimination against competing metal ions. These systems exploit simultaneous fluorescence and colorimetric responses, enabling ratiometric analysis that minimizes background interference and improves quantitative accuracy. This review critically summarizes recent developments in organic, inorganic, and hybrid Zn²⁺ probes, highlighting how structural modifications directly influence sensing mechanisms, signal amplification, and stability. In bioimaging applications, many probes demonstrate high cell permeability, low cytotoxicity, and precise visualization of intracellular Zn²⁺ fluctuations, allowing successful imaging of Zn²⁺ in living systems. These advances have enabled deeper insights into zinc-related processes in cancer progression, neurodegenerative disorders, and enzyme regulation. From an environmental perspective, dual-channel probes have shown effective Zn²⁺ monitoring in water, soil, and food samples, with excellent percent recoveries typically exceeding 90% and strong correlation with standard analytical techniques. Integration with portable devices and advanced imaging platforms further demonstrates their potential for real-time, <i>in situ</i> analysis.