An optical material for the detection of trace SO in milk based on a copper complex.

A novel SO luminescent sensor (Cu-p-CPIP) was developed and the presence of SO caused an obvious fluorescence enhancement at 420 nm upon excitation at 330 nm, which could be distinguished with the naked eye under a UV lamp. Remarkably, the compound exhibited excellent selective and sensitive response to SO over other common anions with a micromolar limit of detection (0.442 μM) in DMSO/HO (v/v, 1:1) buffer. The absorbance intensity and the color of Cu-p -CPIP solution changed gradually with the increase of SO concentration. The proposed method was applied to the determination of SO in milk samples and the recoveries were 97.5-105%. The preparation of Cu-p -CPIP exhibited the quick, simple and facile advantages. The results showed that Cu-p -CPIP can be a good candidate for simple, rapid and sensitive colorimetric detection of SO in aqueous solution.