Nanopaper-based photoluminescent enantioselective sensing of L-Lysine by L-Cysteine modified carbon quantum dots

The production and application of chiral nanomaterials are expanding to understand the nature of chiral interactions and to detect chiral molecules due to the chirality is a fundamental characteristics of life processes. With the new advances in optical sensors by combining the advantages of optical signaling unit and sensing platform, new avenues can be opened to produce simple and useful devices for chiral sensor applications. Here, we report construction of nanoscale chirality of carbon quantum dots (CQDs) by functionalization with L-cysteine and application for paper-based sensors. Within this respect, nanopaper made of cellulose nanofibers was prepared and the produced chiral carbon quantum dots (cCQDs) were embedded into nanopaper to gain photoluminescence properties. The chiral sensing behavior of cCQDs was investigated in solution phase and nanopaper. cCQDs exhibited an enantioselective response towards L-lysine among the tested enantiomers of amino acids with a LOD value of 0.30 mM and 0.97 mM for solution phase and nanopaper, respectively.