Turning waste into wealth: Nitrogen-doped carbon quantum dots derived from fruits wastes for sensing.

Hydrothermal treatment of m-phenylenediamine and grape seed powder has been adopted to synthesize nitrogen-doped carbon quantum dots (N-CQDs). The prepared N-CQDs possessed outstanding optical properties and high quantum yield. Based on the combined effect of static quenching effect and inner filter effect of permanganate (MnO4 - ) to N-CQDs and the redox reaction occurred between MnO4 - and L-ascorbic acid (L-AA), an "off-on" fluorescent strategy with N-CQDs has been proposed for the detection of MnO4 - and L-AA. The proposed fluorescent probe was fast, sensitive and selective to MnO4 - and L-AA under mild conditions. Meanwhile, the satisfied results of the proposed strategy for the detection of MnO4 - and L-AA in real samples indicated its practicability.