Nitrogen-doped carbon quantum dots as fluorescent nanosensor for selective determination and cellular imaging of ClO.

The carbon nanomaterial based fluorescent probes have been widely applied in biological imaging. In the current research, we propose an interesting strategy for selective sensing of hypochlorite (ClO) by a water-soluble and highly fluorescent nanosensor based on the N-doped carbon quantum dots (CDs) which was fabricated by a facile and environmental friendly hydrothermal approach from polyvinyl pyrrolidone, L-arginine and tryptophan. The structural characteristics of the probe were measured by multitudinous methods which proved the nanometer spherical structure of the probe and the successfully N-doping. Fluorescent investigation demonstrated that the probe is not only highly stable under interferences of pH, ionic strength, and irradiation, but also significantly selective toward ClO amongst a variety of attractive bioactive species through the fluorescent quenching process which was correlative with the concentration of ClO and linearly in the range of 0.1-50 μmol·L with the sensitivity of 0.03 μmol·L. The probe can also be further illustrated in a prospective application for determination of ClO in environmental water through both solution response and filer paper sensing. Moreover, the positive biocompatibility and ignorable cytotoxicity made the probe a promising effective agent for detection and visualizing ClO in living cells which can facilitate the understanding the oxidative stress from the overexpressing ClO.