Overoxidized polypyrrole/overoxidized poly(3, 4-ethylenedioxythiophene)/graphene quantum dots-chitosan as enhanced electrochemical sensing platform for luteolin determination in peanut shells. (18th October 2022)

• Record Type: Journal Article
• Authors: Meng, Rongqian; Xue, Yanfeng; Guo, Lijun; Yang, Hong; Song, Yongbo; Li, Qiaoling; Niu, Yulan
• Is Part Of: New journal of chemistry. Volume 46:Number 43(2022)
• Page Start: 20610
• Page End: 20622
• Publication Date: 2022-10-18
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d2nj03738f
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : The GQDs-CS, oPPy and oPEDOT can serve as sensitizing elements to improve the sensing performance of a luteolin electrochemical sensor. Abstract : A novel electrochemical sensor was constructed based on an overoxidized polypyrrole/overoxidized poly(3, 4-ethylenedioxythiophene)/graphene quantum dots-chitosan composite film modified glass carbon electrode (oPPy/oPEDOT/GQDs-CS/GCE), for the accurate determination of luteolin in peanut shells. The oPPy/oPEDOT/GQDs-CS/GCE was prepared using layer-by-layer assembly methods. After incubation in NaOH–EtOH solution, the current of luteolin on the composite electrode increased from 0 to ∼30 μA, the R ct value decreased by ∼80 fold, and the specific surface area ( A ) increased by ∼7 fold. Based on a three-level four-factor Box–Behnken design (BBD), the optimal preparation conditions for the composite electrode were as follows: a mass ratio of CS to GQDs of 5, a polymerization cycle number for EDOT of 4, a polymerization cycle number for Py of 4, with the peak current increased to 43.21 μA (RSD = 3.51%, n = 3). A morphology with multi-channels and grooves was observed on the surface of the incubated composite film via SEM analysis. The additional –CN– and –SO/–SO2 groups formed were observed by XPS and FTIR analysis. The electrochemical sensor constructed exhibited good anti-interference ability, repeatability, and stability. The linear detection range recorded by the current responses of the composite electrode to luteolin was 0.01 to 10.0 μM ( R 2 = 0.991) and the limit of detection was 7.5 nM (S/N = 3). The observed content of luteolin in peanut shells was 0.769%, which was close to the results obtained from High Performance Liquid Chromatography (HPLC) analysis (0.808%). This agreement indicated that the constructed electrochemical sensor based on oPPy/oPEDOT/GQDS-CS/GCE was capable of accurate detection of luteolin in peanut shells.