A near infrared fluorescent probe for detection and bioimaging of zinc ions and hypochlorous acid

It is of great significance to monitor zinc ions (Zn2+) and hypochlorous acid (HClO) conveniently in disease diagnosis and environmental protection. Herein, we successfully prepared a near-infrared fluorescent probe based on dicyanoisophorone derivative and methyl hydrazate by Schiff base reaction for effective detection of Zn2+ and HClO. After binding with Zn2+ at a molar ratio of 1:1, the fluorescence intensity (λex = 482 nm, λem = 653 nm) of the probe was significantly enhanced, thus achieving quantitative detection and optical cell imaging of Zn2+. The complexation constant (K) of the probe with Zn2+ was 2.34 × 104 M-1. The response time of the probe for Zn2+ was less than 20 s and the detection limit was 15.3 nM. Moreover, this probe also showed a specific response to HClO. After interacting with HClO, the fluorescence intensity of the probe was increased significantly with a red shift of the emission wavelength from 670 nm to 705 nm (λex = 550 nm). The response time and the detection limit of probe for HClO were 4 min and 1.39 μM, respectively. The probe was successfully applied for visual bioimaging of Zn2+ and HClO inside living cells. The recoveries of Zn2+ and HClO using the probe in actual water samples were satisfactory.