Prussian Blue and Polyvinylpyrrolidone-Embedded Hollow Fiber Gradient Polysulfone Membrane for Uric Acid Biosensor Application

Abstract

Traditional biosensors have drawbacks such as temperature sensitivity and cross-reactivity. An innovative UA biosensor was developed. It combined Prussian Blue, carbon nanotubes, PVP with uricase oxidase in a polysulfone hollow fiber gradient membrane, forming a multilayer 3D structure. The optimal pH and temperature for the biosensor were determined to be 8.0 and 37°C, respectively. Electrochemical impedance spectroscopy (EIS) showed that the nanoparticles significantly reduced the working electrode's impedance, enhancing electron transfer. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the electrochemical behavior of UA oxidation. A distinct oxidation peak for UA was observed at 0.7 V. The sensor exhibited a sensitivity of 0.33 × 10⁻⁶ A/mM, a linear working range from 1.2 to 12 mM, and a detection limit of 0.424 mM. The porous structure of the membrane and the nanoparticles' synergistic effect contributed to high sensor stability. After continuous use for a week, the sensor maintained approximately 90% of its initial performance. This research demonstrates the effectiveness of our method in developing highly sensitive and stable biosensors for UA detection, providing a promising solution for accurate and reliable uric acid level monitoring.