Electrochemical Immune-Determination of Alkaline Phosphatase Based on Gold Nanoparticle/Ti3C2Tx MXenes as the Sensing Platform by Differential Pulse Voltammetry (DPV)

The concentration of alkaline phosphatase (ALP) in serum is an important biomarker for human health, thus the development of a simple method for its determination is important. In this work, the gold nanoparticles/Ti3C2Tx (Au/Ti3C2Tx) MXenes nanohybrids were prepared via a simple self-reduction step and introduced as the sensing platform to immobilize ALP antibodies. Meanwhile, because ALP dephosphorylates 4-amino phenyl phosphate to produce electroactive 4-aminophenol (AP), a simple labeled-free immunosensor was constructed for ALP by recording the differential pulse voltammetry signal of AP. The detection conditions were optimized and the analytical performance was evaluated. Under the optimized conditions, a wide linear range (10.0 to 1500 U L−1) and low detection limit for ALP (4.0 U L−1) were achieved. Furthermore, the selectivity, stability and reproducibility of the immunosensor were investigated, demonstrating desirable results. The results show that the proposed immunosensor has potential applications for practical ALP determination.