Platinum-loaded mesoporous nickel phosphonate and its electrochemical application for sarcosine detection

In 2009, Sreekumar found that sarcosine, as an effective biomarker, can be used to identify prostate cancer. However, it is difficult to detect sarcosine in urine or plasma because of its low concentration. In this work, we describe a simple strategy for the preparation of sarcosine biosensor based on platinum-loaded mesoporous nickel phosphonate (Pt/MNP) and subsequently apply it to detect sarcosine. Mesoporous structure could increase the active sites on the MNP surface, which makes the Pt/MNP have excellent electrochemical performance for detecting hydrogen peroxide, one of the enzymatic products, and the sarcosine biosensor exhibited a superior electrochemical performance. The linear range of sarcosine biosensor is from 5 to 40 μM and the sensitivity is 123.51 μA mM^-1 cm^-2. The limit of detection is estimated to be 0.24 μM (S/N = 3). Additionally, the sarcosine biosensor based on Pt/MNP also shows an excellent performance in the anti-interference test and the real serum sample. This work manifests the potential application of Pt/MNP as a novel biosensor material for sarcosine detection, which could be extended to other oxidase-based detection systems.