Harnessing UiO-66-NH2/LaFeO3 nanocomposite for electrochemical sensing of prednisone

Abstract

Prednisone is a synthetic corticosteroid that mimics cortisol by maintaining blood pressure, the immune system, and inflammatory processes. Its widespread presence in biological systems underscores its involvement in various physiological processes. However, long-term use of prednisone causes several side effects, so detection of prednisone is crucial. Electrochemical sensing has several advantages, including a simple apparatus, high sensitivity, high selectivity, mobility, and the ability to analyse on-site. A sensor capable of detecting prednisone with an enhanced current response has been developed using a UiO-66-NH2/LaFeO3 (ULFO) composite-modified glassy carbon electrode (GCE) for the detection of prednisone at a low detection limit of 0.08 µM. The linear detection range is considered from 0.1 µM to 50 µM. The sensitivity of the ULFO-modified glassy carbon electrode was found to be 0.041 μAμM-1. The morphological and physiological properties of the synthesized materials were investigated. Fourier Transform Infrared Spectroscopy (FT-IR) shows a broad band about 3300-3500 cm-1, which shows the stretching of the amino group. A band near 1650-1550 cm-1 (asymmetrical stretching) and 1400 cm-1 (symmetrical stretching) explains the presence of carboxylate groups. The Fe-O stretching vibration at 490 cm-1 shows the presence of the FeO6 octahedral structure. X-ray Diffraction (XRD) has been utilized to find the crystalline size of the composite (0.84 nm). X-ray photoelectron spectroscopy provided the features of partial hydroxylation of zirconium nodes, and Scanning Electron Microscopy reveals the shape of UiO-66-NH2 to be hexagonal and that of LaFeO3 to be spherical. The composite showed uniform distribution of UiO-66-NH2 on the LaFeO3 surface. The redox activity of the composite ULFO was determined using cyclic voltammetry and differential pulse voltammetry, and the repeatability, reproducibility, selectivity, and stability were evaluated.