Electrochemical determination of mercury ions in different food samples using glassy carbon electrode modified with poly (crocin)

[Display omitted] •Electropolymerization of Crocin on the GCE surface was designed for the first time.•PCro/GCE was fabricated, characterized, and employed for mercury ion detection.•PCro/GCE performs well in terms of repeatability, reproducibility, and stability.•The modified electrode was used to detect Hg2+ in various food samples. In this study, a glassy carbon electrode (GCE) modified with poly (crocin) (GCE/PCro) was designed for Hg2+ detection through the differential pulse anodic stripping voltammetry (DPASV) technique as a novel electrochemical sensor. Herein, differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and field emission-scanning electron microscopy (FE-SEM) were carried out to characterize the electrodes. Under optimal conditions, the linear range for Hg2+ was obtained at 0.1 to 300 pM and 300 to 2000 pM and, also, the limit of detection (LOD) (S/N = 3) was achieved at 0.033 pM. The prepared sensor was found to exhibit the qualities of selectivity, stability, repeatability, and reproducibility ability. To demonstrate the introduced sensor ability for real application, the modified electrode was employed to measure Hg2+ in tea, shrimp, and fish samples with a good recovery ranging from 98.50 to 103.02 – depicting that the modified electrode possesses satisfactory practicability to detect Hg2+.