An ultrasensitive MnO2-S,O-doped g-C3N4 nanoprobe for turn-on detection of glutathione and cell imaging

The utilization of nanomaterial-based probes in detecting glutathione (GSH) and cell imaging has aroused extensive attention owing to the excellent properties of nanoprobes. Herein, we have synthesized manganese dioxide-S, O co-doped graphitic carbon nitride quantum dots (MnO2-S, O-CNQDs) nanocomposite by in situ synthesis of MnO2 nanosheets in S,O-CNQDs dispersion solution. It was found that GSH could specifically bind to MnO2-S, O-CNQDs so that the fluorescence of S, O-CNQDs could be recovered. As such, a turn-on MnO2-S, O-CNQDs nanoprobe can be fabricated and applied to rapidly determine trace amounts of GSH. Under the optimal conditions, MnO2-S, O-CNQDs shows sensitive response to GSH in the range 10-270 mu M with a detection limit of 0.307 mu M (S/N = 3). The developed MnO2-S, O-CNQDs probe has demonstrated great potential to detection of GSH in biological samples and glutathione injections. What is more, MTT assay indicates that MnO2-S, O-CNQDs has low biotoxicity. The non-fluorescence MnO2-S, O-CNQDs reacts with GSH to recover the fluorescence of S, O-CNQDs in HepG2 cells. Thus, the turn-on fluorescence change of MnO2-S, O-CNQDs offers a potentially useful tool to monitor GSH of cancer cells. [GRAPHICS] .

Automated summary

A MnO2-S, O-CNQDs nanoprobe was developed for rapid detection of trace amounts of GSH, showing potential biomedical applications and low biotoxicity. The non-fluorescence MnO2-S, O-CNQDs reacted with GSH to recover fluorescence, offering a useful tool for monitoring GSH in cancer cells.