Fe3O4-Nanoparticle-Modified Sensor for the Detection of Dopamine, Uric Acid and Ascorbic Acid

Abstract

A simple electrochemical sensor based on electrochemically synthesized Fe3O4 nanoparticles was constructed by an ink with the nanoparticles, isopropanol, NAFION and carbon Vulcan to detect dopamine, uric acid and ascorbic acid. The electrocatalytic activity of the nanoparticles for the oxidation of the analyte molecules was examined by means of cyclic voltammetry and square wave voltammetry. The parameters controlling the performance of the sensor were optimized, such as the amount of Fe3O4 nanoparticles (1, 2, 3, 5, 8, 10 mg), amount of binder (5, 10, 15 µL) and carbon Vulcan in the ink (4, 6, 8 mg). The temperature was maintained at 25 °C and the pH was 7.5 with buffer phosphate. The optimal sensor conditions were 8 mg magnetite, 4 mg carbon Vulcan and 5 µL of NAFION@ 117. The calibration curves for the three analytes were determined separately, obtaining linear ranges of 10–100, 20–160 and 1050–2300 µM and limits of detection of 4.5, 14 and 95 µM for dopamine, uric acid and ascorbic acid, respectively. This electrochemical sensor has also shown significant sensitivity and selectivity without interference from the three analyte molecules presented simultaneously in solution. This sensor was applied for the detection of these molecules in real samples.

Functionalized EGaIn Electrodes with Tunable Reduced‐Graphene‐Oxide Assembled EGaIn Core–Shell Particles for Soft and Deformable Electrochemical Biosensors

“…The aforementioned biomolecules are vital in human metabolic processes, and their abnormal levels have been associated with serious diseases such as Parkinson's disease, gout, and leukemia. [54][55][56] Consequently, the selective and simultaneous detection of AA, DA, and UA becomes essential for fast clinical diagnosis and health monitoring. However, achieving selective and simultaneous detection can be challenging due to their coexistence in biological fluids and their similar oxidation potentials.…”

Highly sensitive amperometric sensors based on laccase-mimetic nanozymes for the detection of dopamine

“…[11][12][13][14][15] A number of low-cost laccase-like nanozymes NZs possessing high catalytic activity have been described and used for the development of DA-sensitive sensors, in particular, nanoparticles of Ni, 16 Pd, 17 Co, 18 Au, 19 Cu, 20 different nanooxides and suldes (FePt-Fe 3 O 4 , Fe 3 O 4 , Au@Fe 3 O 4 , ZnFe 2 O 4 , MoS 2 ), some polymers, carbon nanomaterials (single-walled nanotubes, multi-walled nanotubes) and carbon-based materials functionalized with metal NPs. [21][22][23][24][25][26] Detection of DA by electrochemical methods is not an easy task and is complicated by other redox biomolecules that can be oxidized at similar potentials, such as ascorbic acid or uric acid. Despite the numerous advantages of electrochemical sensors, their application to assay the neurotransmitter in human samples faces serious challenges due to presence of interfering compounds.…”