Electrochemically Polymerized DL‐Phenylalanine‐Deposited Graphene Paste Electrode for the Detection of Rutin

Abstract The sensitive, economical, green, and simple voltammetric sensor for the detection of the redox behaviour of rutin (RT) was prepared by the electrochemical polymerization approach. The constructed polymerized DL‐phenylalanine (DL‐PN) modified graphene paste electrode (MGPE) and bare graphene paste electrode (BGPE) were elucidated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopic (EIS) and field emission scanning electron microscopic (FE‐SEM) approaches. The analysis of RT in phosphate‐buffered saline (PBS) of pH 6.5 was demonstrated by the application of a modified electrode (Poly(DL‐PN)MGPE) with higher electrocatalytic activity and active sites as compared to BGPE. The important electrochemical parameters such as the influence of PBS, pH, scan rate, and concentration of RT on Poly(DL‐PN)MGPE were evaluated. The variation of scan rate and PBS pH assessment discloses that the RT redox nature at Poly(DL‐PN)MGPE surface has proceeded via pH‐dependant and adsorption‐controlled pathways. The Poly(DL‐PN)MGPE senses RT in the range from 0.2 to 10.0 μM with a lower limit of detection (LOD) value of 8.31 nM and a limit of quantification (LOQ) of 27.70 nM. The Poly(DL‐PN)MGPE shows excellent reproducibility, antifouling nature, repeatability, and stability for the detection of RT. Also, the Poly(DL‐PN)MGPE analytical applicability was discussed for RT detection in citrus fruit juice samples.