Thioglycolic acid-capped gold nanoparticle/cytochrome p450-2e1 electrochemical biosensor for isoniazid

Abstract

Tuberculosis (TB) is one of the deadliest diseases in Africa and it is classified as a serious global health problem. A new threat associated with the disease is the emergence of multidrug-resistant TB (MDR-TB), which results from improper dose or non-compliance with a treatment regime. It is, therefore, important to determine a patient's rate of TB drug metabolism at a point-of-care, in order to enable appropriate dose prescription. This work presents a novel enzymatic nanobiosensor for real-time determination of isoniazid (INH), which is a highly prescribed drug for TB treatment. The nanobiosensor consists of a cytochrome P450-2E1 (CYP2E1) isoenzyme covalently attached to a screen printed or disk gold electrode (Au), functionalized with thioglycolic acid-capped gold nanoparticle (TGA-AuNP). The nanomaterial was green-synthesized with banana peel extract (BPE) as the reducing agent. It exhibited an ultraviolet-visible spectroscopy (UV–Vis) signature absorption band for AuNP at 536 nm and a direct bandgap energy (Eg) value of 2.00 eV. Fourier transform infra-red spectroscopy (FTIR) was used to confirm the reduction of Au3+ to Au0. High-resolution transmission electron microscopy (HR-TEM) and high-resolution scanning electron microscopy (HR-SEM) studies indicated that TGA-AuNPs were polydisperse and exhibited spherical morphology.