Preparation of sulfur-doped carbon quantum dots from scallion and its application for fluorescence sensing of rifampicin

Abstract

Sulfur-doped carbon quantum dots (S-CQDs) with fluorescence quantum yield of 21.3% were entirely established through a facile, low-budget and friendly preparation strategy. The carbon and sulfur sources were scallion and 2-mercaptopyrimidine. The as-fabricated S-CQDs implied a significant emission signal around 449 nm at the excitation wavelength of 376 nm. Surprisingly, rifampicin could quench the emission signal around 449 nm of S-CQDs. According to the above fluorescence change phenomenon, we exploited a fluorescence platform for the measurement of rifampicin. Additionally, the fluorescence weakening mechanisms of the S-CQDs were discussed. A wide linear range of 0.5–100 μM and detection limit of 0.083 μM were obtained based on the fluorescence data. Gratifying experimental results were obtained when this platform was applied to detect rifampicin in actual samples.