Convenient Heme Nanorod Modified Electrode for Quercetin Sensing by Two Common Electrochemical Methods

Quercetin (Qu) is one of the most abundant flavonoids in the human diet. High concentrations of Qu can easily cause adverse effects and induce inflammation, joint pain and stiffness. In this study, Heme was used as a sensitive element and deposited and formed nanorods on a glassy carbon electrode (GCE) for the detection of Qu. The Heme/GCE sensor was characterized using scanning electron microscopy (SEM), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Under optimized conditions, the developed sensor presented a linear concentration ranging from 0.1 to 700 mu mol center dot L-1 according to the CV and DPV methods. The detection limit for the sensor was 0.134 mu mol center dot L-1 and its sensitivity was 0.12 mu A center dot mu M-1 center dot cm(-2), which were obtained from CV analysis. Through DPV analysis we obtained a detection limit of 0.063 mu mol center dot L-1 and a sensitivity of 0.09 mu A center dot mu M-1 center dot cm(-2). Finally, this sensor was used to detect the Qu concentration in loquat leaf powder extract, with recovery between 98.55-102.89% and total R.S.D. lower than 3.70%. The constructed electrochemical sensor showed good anti-interference, repeatability and stability, indicating that it is also usable for the rapid detection of Qu in actual samples.

Automated summary

A sensor utilizing Heme nanorods on a glassy carbon electrode was developed for the detection of Quercetin. The sensor showed good linear range and sensitivity, demonstrating excellent detection performance in real samples.