Determination of trace chlorine dioxide based on the plasmon resonance scattering of silver nanoparticles

A plasmon resonance scattering (PRS) method for chlorine dioxide is reported based on the oxidization of silver nanoparticles (NPs) by it, in pH 9.1 ammonia-ammonium nitrate buffer solutions. Silver NPs exhibit strong PRS signals at 470nm, and can be oxidized by ClO(2), which results in PRS quenching at 470nm. It was found that the PRS quenching intensity is proportional to the concentration of chlorine dioxide over the range of 0.0011-0.185microg/mL, with a detection limit (3sigma) of 0.00050microg/mL and the correlation coefficient of 0.9995. The method is simple, rapid and cost effective. It was applied to the determination of chlorine dioxide in drinking water, with satisfactory results.