Ligand-modulated synthesis of gold nanoclusters for sensitive and selective detection of folic acid

Abstract Precisely changing the optical properties of gold nanoclusters (AuNCs) with different ligands offers a promising prospect for highly sensitive and selective drug sensing. In this study, AuNCs were synthesized d -tryptophan ( -Trp) its derivatives as ligands. Optical measurements showed that -Trp@AuNCs produced higher fluorescence intensity shorter emission wavelength than -Trp-derivatives-ligands protected AuNCs, indicating ligand-shell rigidity core-shell charge transfer affected their fluorescent properties. At excitation 370 nm, was 460 nm. The changes revealed high selectivity detecting folic acid due to static quenching inner filter effect. presence acid, remarkably quenched good linearity ranging from 6.3-100.0 μM R 2 = 0.997) detection limit 5.8 μM. proposed assay successfully utilized determine amount in human urine recoveries 94.3 107.3%. This work shows great potential real bio-samples. It also presents an effective strategy preparation enhanced efficiency by regulating shell transfer.