Deposited gold nanocrystals enhanced porous PTCA–Cys layer for simultaneous detection of ascorbic acid, dopamine and uric acid

This work described a two-step conjugate synthesis of a porous nanostructured materials (PTCA–Cys) composed of 3,4,9,10-perylenetetracarboxylic acid (PTCA) and l-cysteine (Cys) and then the sensor prepared by the deposited gold nanocrystals (DpAu) immobilized in this nanostructure film was developed. The interesting PTCA–Cys layer not only could provide SH-functionalized interface but also easily forms a stable thin film on the electrode surface with the porous nanostructure, thus, it is very beneficial to electrode modification. Furthermore, with the DpAu film onto PTCA–Cys modified electrode, the proposed sensors exhibited the excellent catalytic activity and the high selectivity toward the oxidation of AA, DA and UA. Moreover, scanning electron microscopy, cyclic voltammetry and different pulse voltammetry were employed to characterize the sensors. Under the optimal conditions, the linear response range for simultaneous detection of AA, DA, and UA were 20–700 μM, 2–402 μM and 0.4–252.4 μM, respectively, and the detection limits were 6.40 μM, 0.67 μM and 0.12 μM (S/N = 3). More importance, the proposed method offers promise for simple, rapid and cost-effective analysis of small biomolecules.