Rapid, Selective Fluorescent Determination of Copper (II) in Aqueous Solution and Living Cells Using a Dansyl-Based Click Probe.

A novel 1,2,3-triazole based dansyl fluorophore has been designed and synthesized for detecting Cu2+ as a fluorescent probe (P1). The probe P1 exhibited high sensitivity and selectivity for Cu2+ compared to other selected species in aqueous solution within a wide pH span (5 to 14), which showed that P1 may be applied in the entire alkaline pH window. The limit of detection (LOD) was measured to be as low as 5 × 10−7 mol/L for Cu2+. A 1:2 binding ratio and association constant of 4.6 × 104 M−1 between P1 and Cu2+ were determined. Additionally, rapid response to Cu2+ was demonstrated in less than 3 seconds and the linear concentration range was from 0.5 to 2.5 µmol/L. Moreover, probe P1 showed good biocompatibility and cell membrane permeability and was successfully applied for imaging Cu2+ in water samples and living cells, which demonstrates the application of P1 in complicated environments. [ABSTRACT FROM AUTHOR]