Bioinspired thiol functionalized carbon dots for rapid detection of lead (II) ions in human serum

Abstract

Recently, carbon dots (CDs) have attracted considerable attention because of their optical properties and biocompatibility. They have been used in various applications including biological labels, biosensors and ion detection. Herein, fluorescent CDs with thiol functional groups were prepared by a one-pot hydrothermal method using L-lysine and L-glutathione for the detection of lead (Pb2+) ions. The CDs were spherical in shape with an average diameter of 5 nm. They exhibited excitation-wavelength-dependent photoluminescence (PL) emission with excellent long-term PL intensity stability. The PL quenching of the CDs was used to detect Pb2+ ions, with high selectivity over various other metal ions. The limit of detection (LOD) for Pb2- ions was 2.2 pM in human serum.