Polysulfone Hydrogel Nanocomposite Alkaline Phosphatase Biosensor for the Detection of Vanadium

摘要

Several biosensors based on the immobilization of alkaline phosphatase (ALP) at different transducers have been reported in literature. In this work, a gold electrode covalently modified with a hydrogel (Au-HGL) was used as a platform for the immobilization of ALP enzyme to produce Au-HGL/ALP biosensor. The biosensor construction was evaluated by Raman spectroscopy, cyclic voltammetry (CV), and atomic force microscopy (AFM). The analytical performance of the biosensor was assessed by square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS), and amperometry. The calibration curve displayed a dynamic linear range of 0.5-30 mu M with a detection limit (LOD) and quantification limit (LOQ) of 0.23 mu M and 0.76 mu M, respectively. Determination of vanadium in commercial Centrum (R) tablet using the proposed biosensor was satisfactory when compared to other analytical methods. The proposed Au-HGL/ALP biosensor exhibited high sensitivity to vanadium in an aqueous medium with a good reproducibility (n = 4) and a relative standard deviation (RSD) of 8.0%.