Mediatorless Impedance Studies with Titanium Dioxide Conjugated Gold Nanoparticles for Hydrogen Peroxide Detection

Abstract

An impedimetric-based biosensor constructed using gold nanoparticles (AuNP) entrapped within titanium dioxide (TiO₂) particles for hydrogen peroxide (H₂O₂) detection is the main feature of this research. The matrix of the biosensor employed the surface of TiO₂, which was previously modified with an amine terminal group using 3-Aminopropyltriethoxysilane (APTS) at a low temperature to create a ready to immobilise surface for the biosensor application. Hemoglobin (Hb), which exhibits peroxidase-like activity, was used as the bioreceptor in the biosensor to detect H₂O₂ in solution. The analysis was carried out using an alternative impedance method, in which the biosensor exhibited a wide linear range response between 1 × 10⁻⁴ M and 1.5 × 10⁻² M and a limit of detection (LOD) of 1 × 10⁻⁵ M without a redox mediator.