Enhancement of periodate-hydrogen peroxide chemiluminescence by nitrogen doped carbon dots and its application for the determination of pyrogallol and gallic acid

• Nitrogen doped carbon dots (N-CDs) were disposed from histidine as a sole source by hydrothermal way.
• The ultra-weak chemiluminescence from KIO4–H2O2 was strongly enhanced by N-CDs.
• The mechanism of N-CDs-enhanced CL was revealed as catalytic effect along with CRET, and electron and hole annihilation process.
• The N-CDs enhanced CL system was used for the determination of pyrogallol and gallic acid.

A new sensitized chemiluminescence (CL) was developed to broaden the analytical application of KIO4–H2O2 system. The nitrogen doped carbon dots (N-CDs) dramatically boosted the CL intensity of KIO4–H2O2 system which was further enriched by basic medium. In light of EPR analysis, free radical scavenging studies and CL spectra the detail mechanism for the enhancement was conferred in the presence of N-CDs and NaOH. The results suggested that CL of KIO4–H2O2 system in the presence and absence of N-CDs and NaOH proceeds via radical pathway. The enhanced CL was used for the determination of pyrogallol and gallic acid in range of 1.0×10−4–1.0×10−7 M with 4.6×10−8 and 6.1×10−8 M limit of detection respectively. The relative standard deviation (RSD) at a concentration of 10−5 for gallic acid and pyrogallol was 1.4% and 2.3% respectively (n=11). The attained results unveil that the present method is sensitive, faster, simpler and less costly compared to other methods and could be applied to determine polyphenols in real samples.

The mechanism of the N-CDs-enhanced KIO4–H2O2 CL was revealed as decomposition-assisted catalytic effect along with chemical resonance energy transfer (CRET) and electron and holes induction and annihilation process, based on studies of CL emission spectra, electron spin resonance spectra, UV–vis absorption, fluorescence spectra and free radical scavenging studies.Figure optionsDownload as PowerPoint slide