Direct chemiluminescence of fluorescent gold nanoclusters with classic oxidants for hydrogen peroxide sensing

Direct chemiluminescence (CL) of fluorescent gold nanoclusters was observed for the first time upon oxidation with classic oxidants. The CL mechanism was investigated by the studies of CL spectrum, UV–vis absorption spectra and X-ray photoelectron spectra before and after the reaction. The excited state Mn(II)^∗, originating from the reduction of permanganate with gold nanoclusters, was suggested as the possible luminophor for the reaction. The potential analytical application was demonstrated by using hydrogen peroxide as an example, based upon the fact that hydrogen peroxide decreased the CL signal significantly. The decreased CL intensity was proportional to the concentration of hydrogen peroxide in the range 1.0 × 10⁻⁶–1.0 × 10⁻⁴ mol L⁻¹. The detection limit was 5 × 10⁻⁷ mol L⁻¹ and the relative standard deviation was 1.4% for 1.0 × 10⁻⁵ mol L⁻¹ hydrogen peroxide in 11 replicated measurements. This method was applied to the determination of hydrogen peroxide in water samples with satisfactory results.