Chiral Fe x Cu y Se nanoparticles as peroxidase mimics for colorimetric detection of 3, 4-dihydroxy-phenylalanine enantiomers

Abstract

L-3,4-dihydroxy-phenylalanine (L-dopa) is the most widely used drug in Parkinson’s disease treatment. However, development of cost-effective and high-throughput sensors to accurate enantioselective discrimination of L-dopa and D-dopa remains challenging to date. Herein, on the basis of the peroxidase-mimic activity of chiral Fe x Cu y Se nanoparticles, we demonstrated a novel colorimetric sensor for determination of chiral dopa. The surface chiral ligand, L/D-histidine (L/D-His), endowed the nanozymes with enantioselectivity in catalyzing the oxidation of dopa enantiomers. According to the values of k cat/K m, the efficiency of L-His modified nanoparticles (L-Fe x Cu y Se NPs) towards L-dopa was 1.56 times higher than that of D-dopa. While, D-His can facilely reverse the preference of the nanozyme to D-dopa. On the basis of high catalytic activity and enantioselectivity of L-Fe x Cu y Se NPs in oxidation of L-dopa, the L-Fe x Cu y Se NPs-based system can be utilized for detection of L-dopa. The linear ranges for L-dopa determination were 5 μM–0.125 mM and 0.125 mM–1 mM with a detection limit of 1.02 μM. Critically, the developed sensor has been successfully applied in the quality control of clinical used L-dopa tablets. Our work sheds light on developing simple and sensitive chiral nanomaterials-based sensors for drug analysis.