A β-nicotinamide adenine dinucleotide electrochemical sensor based on polyoxometalate built by the combination of electrodeposition and self-assembly

Abstract

• A NADH sensor was developed by electrodeposition combining the LbL method. • The current of NADH was greatly improved by this sensor. • The sensor exhibited wide linear range, low detection limit and high selectivity. • The combination of electrodeposition and LbL provided strong stability of sensor. β-nicotinamide adenine dinucleotide (NADH), as vital coenzyme involved, is expected to be accurately detected in Clinical diagnosis and treatment. Polyoxometalates (POMs) have unique redox capacity with good electrochemical reversibility and fast electron transfer ability, which makes them become favorite materials for sensors. Here by using alternating electrodeposition and self-assembly techniques, Keggin-type polyoxometalates (PMo 11 V) were modified on glassy carbon electrodes with the help of polyallylamine hydrochloride (PAH), to construct a sensitive and stable electrochemical sensor for detection of NADH. The proposed (PAH/PMo 11 V) 4 /GCE was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV) measurements and amperometrics method (i-t). The obtained electrode has high stability, good reproducibility, outstanding sensing capability for NADH, with a low detection limit of 1.9 × 10 -8 M, a wide linear range from 3.2 × 10 -7 to 8.2 × 10 -5 M and 1.1 × 10 -5 to 1.01 × 10 -3 M. This strategy, overcoming the drawbacks of POMs and solving the shortcomings that NADH requires high electrocatalytic potential, is simple in operation, low in cost, and could be widely used in electrochemisty field.