Characterization of poly(5-hydroxytryptamine)-modified glassy carbon electrode and applications to sensing of norepinephrine and uric acid in preparations and human urines

• Published in: Electrochimica acta 2013-03, Vol.92, p.341-348
• Main Authors: Shi, Peiying, Miao, Xiaoqing, Yao, Hong, Lin, Sijie, Wei, Biyu, Chen, Jianji, Lin, Xinhua, Tang, Yuhai
• Format: Article
• Language: English
• Subjects: 5-Hydroxytryptamine; Electro-polymerization; Electrochemical impedance spectroscopy; Electrodes; Glassy carbon; Human; Modified electrode; Norepinephrine; Uric acid; Urine; Voltammetry
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2013.01.033

A 5-hydroxytryptamine (5-HT) modified electrode was fabricated by electro-polymerization of 5-HT on a glassy carbon electrode (GCE) by cyclic voltammetry (CV) in 0.05M PBS (pH 7). The characterization of the modified electrode was carried out by atomic force microscopy (AFM), voltammetry and electrochemical impedance spectroscopy (EIS). The mechanism of electro-deposition of 5-HT at GCE was discussed based on electrochemical studies and quantum chemical calculations. The poly(5-HT)-modified electrode could separately detect NE and UA, even in the presence of 10-fold concentration of ascorbic acid (AA) and was applied successfully to the analysis of NE preparations and healthy human urines. Due to the favorable functionalized groups (NH2 and OH), electroactivity, biocompatibility and stability, the poly(5-HT) film could be a promising immobilization matrix for anchoring interested biological molecules in the fabrication of sensors and biosensors. [Display omitted] ► A poly(5-HT)-modified electrode was fabricated originally by CV. ► The electro-deposition mechanism of 5-HT at GCE was proposed. ► The polymer film shows favorable electrocatalytic properties to NE and UA. ► The modified GCE was applied to the sensing analysis of real samples. A poly(5-hydroxytryptamine) (poly(5-HT)) modified electrode was fabricated by electropolymerization of 5-hydroxytryptamine (5-HT) on a glassy carbon electrode (GCE) by cyclic voltammetry (CV) in 0.05M PBS (pH 7). The characterization of poly(5-HT)-modified electrode was carried out by atomic force microscopy (AFM), voltammetry and electrochemical impedance spectroscopy (EIS). Results showed that a brown and heterogeneous film was formed on the surface of the modified electrode. The mechanism of electro-deposition of 5-HT at GCE was discussed. The modified electrode showed good affinity and electrocatalytic properties to some species, such as norepinephrine (NE) and uric acid (UA). Furthermore, the poly(5-HT)-modified electrode could separately detect NE and UA, even in the presence of 10-fold concentration of ascorbic acid (AA). The modified electrode could be stored stable for at least 2 weeks in 0.05M PBS (pH 4) at 4°C. Owing to its favorable electroactivity, biocompatibility and stability, the prepared poly(5-HT) film could be considered as an immobilization matrix candidate for anchoring of interested biological molecules in the fabrication of biosensors. In addition, the poly(5-HT)-modified GCE was applied successfull