Yellow fluorescent carbon quantum dots for Ag+/GSH detection and differentiation between normal and cancer cells

Abstract

In this paper, a novel multifunctional fluorescent carbon quantum dot (CDs) was prepared by the solvothermal method in which o-phenylenediamine (OPD) was used as the carbon source, p-aminobenzoic acid (PABA) was used as the nitrogen source and ethanol was used as the reaction solvent. The prepared CDs possessed fluorescence “off” response toward silver ions (Ag+) with a minimum detection limit of 75 nM. Meanwhile, glutathione (GSH) as an amino acid could selectively restore the fluorescence performance of CDs quenched by Ag+ ions and showed good detection sensitivity (detection limit of 10 nM). Owing to the low cell toxicity and high biocompatibility, the application of CDs in cell imaging demonstrated that they could be used as a distinguishing recognition between normal cells (EC) and cancer cells (MCF-7) because of their highly precise sensing ability for GSH. All of the above indicated that the prepared CDs would have great application prospects in biological diagnosis and sensing.