A dual-functional fluorescent probe based on coumarin derivative for highly sensitive and intelligent detection of Zn2+/Cu2+ and cell imaging

Fluorescent molecules are widely used in detection of molecules and ions, medical diagnosis and bio-imaging because of their advantages such as non-damage, less interference, good specificity and sensitivity. Zinc and copper ion (Zn²⁺/Cu²⁺) are important micro-nutrients and pollutants to require rapid determination and monitoring. In this work, a fluorescent probe L with fast response, good stability and wide pH ranges starting from inexpensive and readily available substrates was synthesized via a simple synthetic process. Based on fluorescence emission enhancing or quenching, probe L can sensitively detect Zn²⁺ and Cu²⁺ with the lowest detection limits of 4.99 × 10^-7 and 3.56 × 10^-10 mol/L, respectively. The mechanisms on Zn²⁺ and Cu²⁺ recognition had been further disclosed by spectral analysis, density functional theory calculations and single crystal. An intelligent sensing system based on probe L hydrogel chip and smartphone had conveniently been constructed to carry out rapid and portable determination of Zn²⁺and Cu²⁺. Moreover, probe L can also be applied to fluorescence imaging of live cells and detection of water samples, indicating that probe L may have good application potential in environmental analysis and biomedicine.