Tyrosinase/Chitosan/Reduced Graphene Oxide Modified Screen-Printed Carbon Electrode for Sensitive and Interference-Free Detection of Dopamine

• Main Authors: Cheng-You Liu, Yi-Chieh Chou, Jui-Hsuan Tsai, Tzu-Ming Huang, Jian-Zhang Chen, Yi-Chun Yeh
• Format: Article
• Language: English
• Published: MDPI AG 2019-02-01
• Series: Applied Sciences
• Subjects: screen printing; electrochemical biosensor; tyrosinase; chitosan; dopamine; reduced graphene oxide
• Online Access: https://www.mdpi.com/2076-3417/9/4/622
• ISSN: 2076-3417

Tyrosinase, chitosan, and reduced graphene oxide (rGO) are sequentially used to modify a screen-printed carbon electrode (SPCE) for the detection of dopamine (DA), without interference from uric acid (UA) or ascorbic acid (AA). The use of tyrosinase significantly improves the detection’s specificity. Cyclic voltammetry (CV) measurements demonstrate the high sensitivity and selectivity of the proposed electrochemical sensors, with detection limits of 22 nM and broad linear ranges of 0.4⁻8 μM and 40⁻500 μM. The fabricated tyrosinase/chitosan/rGO/SPCE electrodes achieve satisfactory results when applied to human urine samples, thereby demonstrating their feasibility for analyzing DA in physiological samples.