Amplified Electrochemical Response of Phenol by Oxygenation of Tyrosinase Coupling with Electrochemical‐chemical‐chemical Redox Cycle. Issue 9 (6th June 2019)

• Record Type: Journal Article
• Authors: Guo, Liping; Du, Hui; Zhao, Huiying; Li, Jian
• Is Part Of: Electroanalysis. Volume 31:Issue 9(2019)
• Page Start: 1728
• Page End: 1735
• Publication Date: 2019-06-06
• Subjects: Electrochemical signal amplification -- Redox cycling -- Sulfonated polyaniline -- Tyrosinase -- Phenol; Electrochemical analysis -- Periodicals; Chemistry, Analytical -- Periodicals; Electrochemistry -- Periodicals; 543.4
• DOI: 10.1002/elan.201900174
• Languages: English
• ISSNs: 1040-0397

Abstract

Abstract: In this work, an novel electrochemical‐chemical‐chemical (ECC) redox cycle was designed in an enzyme‐based sensor for acquiring additional signal amplification. The tyrosinase (Tyr) was entrapped in a sulfonated polyaniline−chitosan (SPAN−CS) composite which was used as a redox capacitor on a glass carbon electrode. Firstly, the substrate, phenol was catalyzed to catechol and further catalyzed to o‐benzoquinone by Tyr. Next, in the presence of Ru(NH3 )6 Cl2, the reduced state of SPAN(SPANred ) was reacted with o‐benzoquinone to form it's oxidized state (SPANox ) and catechol, then SPANox was reduced back to SPANred by Ru(II) in the solution. Finally, the amplified anodic current of catechol was obtained on electrode through above ECC redox cycle system. In addition, the ECC redox cycling led to a high signal‐to‐background ratio. The voltammetric response showed excellent analytical performance to phenol over two linear range of 3.5 to 200.0 nmol L −1 and 200.0 to 2000.0 nmol L −1 with a high sensitivity of 2204 μA mM −1 . The detection limit was obtained to be 0.8 nmol L −1 (S/N=3). Furthermore, the proposed approach exhibited good repeatability, stability and specificity, and could offer practicality in the detection of phenol in tap water. Abstract :