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Ultra-weak chemiluminescence (CL) from the reaction of iodide and KMnO was strongly enhanced by carbon nanodots (CNDs) in an acidic medium. The CL intensity was directly proportional to the concentration of iodide in the solution. Therefore, a flow-injection CL system with high sensitivity, selectivity and reproducibility is proposed for the determination of iodide. The proposed method exhibited advantages over a linear range of 3.0 × 10 -1.0 × 10 mol/L and had a detection limit of 3.5 × 10 mol/L. The method was successfully applied to the evaluation of iodide in food samples with recoveries of between 96 and 103%. The relative standard deviations were 2.1 and 4.1% for intra- and inter-assay precision, respectively.

A rapid and sensitive chemiluminescence (CL) method has been found for the determination of isonaphthol. Carbon dots (CDs), synthesized by the ultrasonic method using glucose as carbon precursor, could significantly catalyze the CL reaction between luminol and KMnO4 at extremely low concentrations in an alkaline medium. Moreover, the CL intensity of the CD–luminol–KMnO4 system was further enhanced in the presence of isonaphthol. Based on this finding, a novel CL method for the determination of isonaphthol was developed. Under optimum experimental conditions, CL intensity was proportional to the concentration of isonaphthol in the range 0.1–10.0 μM. The detection limit was 23.0 nM. The method was successfully applied for the determination of trace isonaphthol in water samples. The possible CL mechanism was investigated.

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Graphene oxide (GO), one of the water-soluble derivatives of graphene, could initiate strong chemiluminescence (CL) emission of luminol in the absence of any oxidant, and then the CL intensity was inhibited by puerarin (PUE), a main component in the traditional Chinese medicine Gegen. Based on this, a novel CL method was established for the determination of PUE. This method showed a linear relationship between the CL signal and the logarithm of PUE concentration in the range 0.01-6.00 μM. The limit of detection was 2.83 nM and the relative standard deviation (RSD) was 1.94% for 11 determinations of 0.4 μM PUE. This method was successfully used for the determination of PUE in Gegen and human urine samples. The possible CL reaction mechanism was investigated by UV-vis, fluorescence, and CL spectra, as well as by some chemical experiments.