A dopamine sensor based on a methoxypolyethylene glycol polymer covalently modified glassy carbon electrode

Abstract

A dopamine (DA) sensor based on a methoxypolyethylene glycol (MPEG) polymer covalently modified glass carbon electrode (GCE) was fabricated by an electroadsorption method. The electrochemical behavior of the sensor towards the catalytic oxidation of DA in pH 5.0 phosphate buffer solution (PBS) was investigated by cyclic voltammetry. The modified electrode obviously enhanced the current response and decreased the overpotentials for the oxidation of DA. Using differential pulse voltammetry, the sensor gave a linear response to DA over the concentration range of 2.0-140 μM with a detection limit (S/N = 3) of 4.68 × 10(-8) M. It was found that MPEG can complex DA through hydrogen bonding interaction between ethylene oxide units of the polymer and the protonated dopamine in acidic PBS and preconcentrate it in the film, which improved the detection limit and sensitivity of DA. The DA sensor exhibits good sensitivity, selectivity and stability, and has been applied for the determination of DA in dopamine hydrochloride injection solution.

A metal-catalyst free, flexible and free-standing chitosan/vacuum-stripped graphene/polypyrrole three dimensional electrode interface for high performance dopamine sensing

“…Both anodic and cathodic peak potentials (E pa and E pc ) shi negatively with increasing pH, indicating the existence of proton transfer at the CHI/VSG/PPy electrode in the redox reaction of DA. 22 A linear relationship is observed for the plot of E pa versus pH (inset of Fig. 3a), with a slope of À55 mV pH À1 which is very close to the theoretical value of À59 mV pH À1 , indicating that equal numbers of electrons and protons are involved in the electrochemical reaction of DA at the CHI/VSG/PPy electrode.…”

A facile one-step synthesis of Fe2O3/nitrogen-doped reduced graphene oxide nanocomposite for enhanced electrochemical determination of dopamine

“…Currently, large numbers of nanomaterials were employed to modify bare electrode for DA detection [6][7][8][9][10]. Hu [8] fabricated a DA sensor based on Au@carbon dots-chitosan composite.…”

Detection of Dopamine by a Biomimetic Electrochemical Sensor Based on Polythioaniline‐Bridged Gold Nanoparticles

“…Several methods have been elaborated for DA determination, including electrochemical methods, the most widely used being amperometry and voltammetry. In addition, the accelerated development of research in the field of composite materials with special properties has sped up developments in the field of electrochemical sensors and biosensors …”