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 mu mol.L-1 with the sensitivity of 0.03 mu mol.L-1. 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-. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, a water-soluble and highly fluorescent nanosensor based on N-doped carbon quantum dots (CDs) was successfully fabricated for selective sensing of hypochlorite. The nanosensor showed high stability under various interferences and exhibited significant selectivity towards ClO-. It could detect ClO- concentration in the range of 0.1-50 μmol.L-1 with a sensitivity of 0.03 μmol.L-1. Additionally, the nanosensor could be applied for determination of ClO- in environmental water and visualizing ClO- in living cells.