Nonenzymatic Amperometric Sensors for Hydrogen Peroxide Based on Melanin-Capped Fe³⁺-, Cu²⁺-, or Ni²⁺-Modified Prussian Blue Nanoparticles

Abstract

Three novel non-enzymatic sensors based on the modification of a glassy carbon electrode with nanoparticles of Fe 3+ , Cu 2+ or Ni 2+ Prussian blue derivatives (PB) are proposed herein. The Fe 3+ -, Cu 2+ -and Ni 2+ -modified Prussian blue nanoparticles were supported in an environmentally-friendly chemical product known as melanin. The nanomaterials prepared were characterized by transmission electron microscopy (TEM) images, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The drop casting method was used to build the enzymeless sensors, which were able to catalyze the oxidation of hydrogen peroxide at +1.5 V. The calibration curves obtained by amperometry were linear in the range of 0.1 to 13.0 mmol L -1 . Several figures of merit were obtained in order to characterize the analytical electrochemical behavior of the as-prepared sensors. For instance, the detection limits achieved were 0.14, 0.32 and 0.57 µmol L -1 for the melanincapped modified Prussian blue nanoparticle sensor containing respectively Fe 3+ , Cu 2+ and Ni 2+ ions. These values are lower than the detection limits provided by other non-enzymatic sensors. The sensors were applied for the detection of hydrogen peroxide in tooth whitening gel. The results obtained were compared with those of the standard method.Index Terms-Non-enzimatic amperometric sensors, Prussian blue derivatives, nanoparticles, hydrogen peroxide, tooth whitening gel.

Micropatterned Silk-Fibroin/Eumelanin Composite Films for Bioelectronic Applications

“…Ever since the discovery of eumelanin as a naturally occurring amorphous semiconductor, there has been interest in eumelanin-based organic electronics, , Numerous studies have been reported for understanding the conduction mechanism of eumelanin along with its unique physical structure and photoprotective or antioxidant properties. ,,− It is known that the hydration state of eumelanin has a significant effect on its electrical properties. , Various melanin-based devices, such as sensors, − energy storage devices, ,, and OECTs, have been reported. Most electrochemical studies have been performed using melanin in ITO/glass and carbon paper or silicon as the substrate.…”