A Simple Interfacial Platform for Homogeneous Electrochemical Immunoassays Using a Poly(Vinylimidazole)-Modified...

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Hippuric acid (HA) is a major metabolite of toluene, an industrial solvent.
• Accurate detection of HA is crucial for monitoring toluene exposure and its health effects.
• Existing methods for HA detection can be complex and time-consuming.

Purpose of the Study:

• To develop a simple, one-step homogeneous detection method for hippuric acid (HA).
• To achieve high sensitivity and a wide linear range for HA analysis.
• To explore the potential application of this method for detecting other small organic molecules.

Main Methods:

• Fabrication of a modified indium tin oxide (ITO) electrode with poly(vinylimidazole) (PVI).
• Immobilization of redox-active pentacyanoferrate coordinated with Ni(II) ions via cyanide bridges.
• Utilizing a competitive binding assay between free HA and a mediator (Fe-HA) for HA antibody detection.

Main Results:

• The developed Ni-PVI-ITO electrode demonstrated sensitive detection of HA.
• Electrical signals were proportional to HA concentration in the range of 0.1 µg/mL to 1.0 mg/mL at low mediator concentrations.
• Characterization confirmed the electrode's properties using cyclic voltammetry, differential pulse voltammetry, FESEM, and XPS.

Conclusions:

• A facile and sensitive one-step method for HA detection was successfully developed.
• The modified electrode system shows promise for the analysis of small organic molecules.
• This approach offers a simplified alternative for monitoring toluene metabolite levels.