Fluorescence resonance energy transfer disposable sensor for copper(II)

A disposable sensor has been developed for the measurement of copper(II) concentration in aqueous solution based on a change in the fluorescence of porphyrazine 2,7,12,17-tetra-tert-butyl-5,10,15,20-tetraaza-21H,23H-porphine (TP). The sensor was constructed by spin-coating a polyester support with a PVC solution containing TP, a plasticizer, the chelating agent Zincon and the ion-pairing benzetonium chloride. The measurement principle is based on the radiationless resonance energy transfer (RET) from TP immobilized in membrane, and acting as fluorescence donor, to Zincon acting as an acceptor induced by copper(II). The absorption spectrum of the Zincon–Cu(II) complex presents adequate overlapping with the emission spectrum of TP, producing a useful analytical signal by the RET process. The disposable sensor responds to copper(II) irreversibly over a dynamic range from 0.039 to 14 mol L−1 (2.5–890 g L−1) with a sensor-tos T s ©