A Novel Highly Sensitive Dual-Channel Chemical Sensor For Sequential Recognition Of Cu2+ And Cn- In Aqueous Media And Its Bioimaging Applications In Living Cells

A simple and unique dual-channel chemical probe (DH) was designed and synthesized, which not only realized sequential recognition of Cu2+ and CN- by colorimetric and fluorometric methods, but also realized fluorescence detection of CN-. When different cations (Co2+, Mg2+, Ni2+, Cd2+, Hg2+, Al3+, Ag+, Cu2+, Pb2+, Fe3+, Zn2+ and Ca2+) were added into the solution containing the probe molecule DH, only Cu2+ induced an observable change in the UV-vis and fluorescence spectra, indicating that the probe molecule can be applied for specific recognition of Cu2+. The anti-interference experiment of DH to Cu2+ showed that DH has good selectivity for detecting Cu2+, with a detection limit of 7.05 x 10(-7) M. In particular, the fluorescence "ON-OFF-ON" process can be recycled by sequentially adding Cu2+ and EDTA, and the fluorescence intensity remained unchanged after ten times. This observation suggested that DH can achieve reversible highly sensitive response to Cu2+ and EDTA, and can be used as a hypersensitive logic gate for Cu2+ detection. More interestingly, when different anions (CH3COO-, SO32-, H2PO(4)(-), ClO4-, NO3-, HSO4-, I-, Cl-, F-, Br-, N-3(-) and CN-) were added into the solution containing DH and Cu2+, only CN- induced color change of the solution from red to yellowish green, and the fluorescence intensity greatly enhanced, indicating that DH-Cu2+ has a specific response to CN-. The anti-interference experiment showed that DH-Cu2+ has good selectivity for CN-, with a detection limit of 8.11 x 10(-6) M. Moreover, the probe molecule DH can detect CN-, with a detection limit of 7.61 x 10(-6) M. Experimental and theoretical methods were applied to deeply study the detection mechanism of DH, present great potential in practical application for ion test strips and HeLa cell imaging reagents.