Composite of a Stabilizer-Free Trimetallic Prussian Blue Analogue (PBA) and Polyaniline (PANI) on 3D Porous Nickel Foam for the Detection of Nitrofurantoin in Biological Fluids

Abstract

Herein, a facile and highly effective nonenzymatic electrochemical sensing system is designed for the detection of the antibacterial drug nitrofurantoin (NFT). This electrocatalyst is a combination of a trimetallic Prussian blue analogue and conductive polyaniline coated onto a three-dimensional porous nickel foam substrate. A comprehensive set of physicochemical analyses have verified the successful synthesis. The fabricated electrochemical sensor exhibits an impressively low limit of detection (0.096 nM) and quantification (0.338 nM, S/N = 3.3), coupled with a wide linear range spanning from 0.1 nM to 5 mM and a sensitivity of 13.9 μA nM −1 cm −2 . This excellent performance is attributed to the collaborative effects of conducting properties of polyaniline (PANI) and the remarkable redox behavior of the Prussian blue analogue (PBA). When both are integrated into the nickel foam, they create a significantly enlarged surface area with numerous catalytic active sites, enhancing the sensor's efficiency. The sensor demonstrates a high degree of specificity for NFT, while effectively minimizing responses to potential interferences such as flutamide, ascorbic acid, glucose, dopamine, uric acid, and nitrophenol, even when present in 2−3-fold higher concentrations. Moreover, to validate its practical utility, the sensor underwent real sample analysis using synthetic urine, achieving outstanding recovery rates of 118 and 101%.