Herein, a novel and green method based on dielectric barrier discharge (DBD) plasma, used as an efficient generator of ˙OH, to synthesize silicon carbide nanoparticles (SiC NPs) was first proposed. Luminescent SiC NPs with excellent optical properties, water-solubility and stability were synthesized from 3-aminopropyl trimethoxysilane under simple reaction conditions (atmospheric temperature and pressure, with simple instruments, and convenient controls) over 1.5 h, compared with traditional methods. Through the characterization of the reactive oxygen species, it is clear that ˙OH generated from O₃ and H₂O₂ under alkaline conditions efficiently played the most vital part in the participation of the oxidation process. Studies demonstrated that the DBD system not only worked for the rapid generation of many reactive species, but also catalysed the complex process to enable rapid synthesis of SiC NPs. In addition, the synthetic mechanism, optical properties, morphology and composition of the SiC NPs were all studied in detail, and we applied the fluorescent SiC NPs to the specific detection of gold(III) ions in the aqueous phase, based on aggregation-induced fluorescence quenching. Furthermore, radical oxidation (˙OH oxidation) by the DBD system could be used in more synthetic methods of nanomaterials and has the potential to be applied to advanced oxidation processes in the environment.