4-Amino-6-hydroxy-2-mercaptopyrimidine capped gold nanoparticles as fluorophore for the ultrasensitive and selective determination of l-cysteine

摘要: Abstract The present study reports the highly sensitive and selective determination of l -cysteine (Cys) using 4-amino-6-hydroxy-2-mercaptopyrimidine capped gold nanoparticles (AHMP-AuNPs) by spectrofluorimetry. AHMP-AuNPs were synthesized wet chemical method characterized UV–visible, HR-TEM, XRD, FT-IR, zeta potential They show emission maximum at 781 nm while exciting 520 nm a large stock shift (261 nm) with narrow profile besides good photostability. On adding 1.75 μM Cys to AHMP-AuNPs, wine red color was changed purple new absorption peak appeared 670 nm. This is due aggregation it confirmed HR-TEM. band does not change less than micromolar concentration Cys. However, intensity enhanced even in presence picomolar Based on enhancement intensity, determined. fluorophore showed an extreme selectivity toward 10,000-fold all other -amino acids. specific interaction via Au–S bond because only amino acid contains –SH group when compared A linearity observed from 10 130 pM detection limit found be 110 fmol L −1 ( S / N  = 3). successfully used for real samples.