▎ 摘　　要

In this work, hydroxyapatite/graphene oxide modified screen-printed electrode (SP-HAp/GO) were investigated for L-tryptophan (Trp) detection using linear sweep voltammetry (LSV) technique. HAp/GO composite was prepared by growth of HAp on GO in the simulated body fluid. Surface wettability, surface morphology and chemical functional group of the modified electrodes were determined by contact angle measurement, scanning electron microscope and Fourier transform infrared spectrometer, respectively. Contact angle of the electrode modified with HAp/GO composite is about two- and three-times larger than those of GO-modified electrode (SP-GO) and bare electrode (SP), respectively. SP-HANGO and SP show rough surface with cracks and pore-like structures, whereas SP-GO forms dense and smooth surface. After electrochemical determination of Trp, the linear range (7-1,000 mu M) and limit of detection (LOD similar to 5.5 mu M) obtained from HAp/GO-modified electrode are better than those of bare (25-1000 mu M, LOD similar to 17.5 mu M) and GO-modified (10-1000 mu M, LOD similar to 7.0 mu M) electrodes. The information from this study may be useful for rapid Trp determination and for development of electrode materials used in bio-molecule sensors. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.