ABSTRACT As essential trace elements in the organism, Ag + plays crucial roles in living systems. Deficiency or excess of Ag + can induce various diseases. Notably, hypochlorite (ClO − ), as a critical component of reactive oxygen species, not only participates in fundamental metabolic processes such as thyroid hormone synthesis but also exerts a crucial function in immune regulation and antibacterial defense. In this study, a bifunctional probe ( BHZ ) based on benzimidazole was designed and constructed. In the presence of Ag + , the fluorescence wavelength of the probe experienced a slight redshift, accompanied by a decrease in fluorescence intensity. The mechanism is attributed to the ICT effect induced by the complexation of BHZ with Ag + , leading to changes in the fluorescence spectrum. Meanwhile, the probe selectively recognize ClO − via a fluorescence “OFF‐ON” response, and the weak blue light of the probe turned into strong green light upon addition of ClO − . The mechanism of ClO − recognition involves addition reaction between ClO − and the probe, thereby inducing structural modifications in the probe that consequently modulated its optical properties. The detection limits of probe BHZ toward Ag + and ClO − were 1.57×10 −8 M and 4.28 nM, respectively. Mass spectrometry was utilized to investigate the response mechanisms of the probe toward Ag + and ClO − . By combining the smartphone color recognition, the rapid and real‐time detection of Ag + by BHZ in real water samples was achieved by using fluorescence ratiometric recognition and test paper. Moreover, the probe BHZ has been effectively deployed for ClO − bioimaging in mice in vivo.
HUAI et al. (2026) studied this question.