New Electrochemical Sensor Based on a Silver-Doped Iron Oxide Nanocomposite Coupled with Polyaniline and Its Sensing Application for Picomolar-Level Detection of Uric Acid in Human Blood and Urine Samples

Abstract

A simple and very sensitive electrochemical sensor for the detection of uric acid (UA) has been developed based on polyaniline (PANI) merged into a silver-doped iron oxide (Ag-FeO) nanocomposite-modified glassy carbon electrode. The synthesized ternary composite material (Ag-FeO@PANI) was characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray, High-resolution transmission electron microscopy, X-ray diffraction, and thermo gravimetric analysis analyses. The nanocomposite-modified electrode shows an exceptional electrocatalytic activity and reversibility to the oxidation of UA in a 0.1 M phosphate buffer solution (pH 7.0) compared to those in PANI and Ag-FeO. The detection limit of UA is found to be 102 pM with a linear dynamic range of 0.001-0.900 μM. The fabricated UA sensor also exhibits good selectivity, reproducibility, and long-time stability. The limit of detection and linear range attained for the synthesized composite are much greater compared to those of any other composite materials reported in the literature. The proposed method has been successfully applied for the selective detection of UA in various real samples such as human serum and urine with good recoveries. This platform that assimilates such electrocatalytic ternary nanocomposite with high performance can be widely employed for fabricating diverse sensors.

A Review on Iron Oxide‐Based Nanoarchitectures for Biomedical, Energy Storage, and Environmental Applications

“…For practical applications, it is important to expand the electrochemical biosensing measurements to real‐life samples, such as human blood and urine. Very recently, ternary iron oxide‐based nanocomposites have shown great potential for the electrochemical sensing of uric acid in both human blood and urine samples, with very low detection limit in the picomolar range . In the future, more in‐depth studies into the size, shape and composition tuning of these ternary nanocomposites may improve their potential application further.…”

Sol-Gel Mediated Greener Synthesis of γ-Fe2O3 Nanostructures for the Selective and Sensitive Determination of Uric Acid and Dopamine

“…It also renowned that the amide groups are have higher acceptor strength of the hydrogen bond than the ester group and it accelerates possible oxidation behavior of UA on the γ-Fe2O3 nanobelts modified GCE. It is also well known that the electrocatalytic oxidation nature of UA is irreversible at the bare GCE and the oxidation reaction of UA takes place via two electron (2e − ) and two proton (2H + ) process [44]. As The γ-Fe2O3 nanostructures/GCE reduces the anodic over potential of the UA with a very sharply increased peak current without the presence of reduction peak.…”

Raman Spectroscopy as an Assay to Disentangle Zinc Oxide Carbon Nanotube Composites for Optimized Uric Acid Detection

“…The development of electrochemical electrode composites for improved UA sensing is an active area of research [14][15][16][17][18][19][20]. The state-of-the-art UA sensing composite employs precious metals in its fabrication [21]. Due to 2 of 13 limitations of resources, sensors employing earth-rich materials that can be facilely fabricated are desirable.…”