A novel non-enzymatic sensor for prostate cancer biomarker sensing based on electrocatalytic oxidation of sarcosine at nanostructured NiMn2O4 impregnated carbon paste electrode

This work addresses the electrocatalytic activity of a binary metal oxide catalyst of NiMn2O4 for electroxidation of sarcosine, the well-known prostate cancer biomarker. The nanocatalyst described was prepared via hydrothermal synthesis route, followed by calcination at 800 degrees C. Field emission scanning electron microscopy and X-ray diffraction were applied to obtain information about the material morphology and structure. A carbon paste electrode modified with nano-NiMn2O4 showed unique catalytic activity in sarcosine electroxidation which led to a significant rise in oxidation current (about four times) in comparison with the blank electrode. However, the carbon paste electrodes containing single oxides of NiO and Mn2O3 exhibited no considerable enhancement in sarcosine signal. The cyclic voltammetry results indicated that the Mn3+/Mn4+ couple was responsible for sarcosine oxidation, and NiO may enhance the content of Mn(4+)species in NiMn2O4 material. The carbon paste-based NiMn2O4 electrode was applied in the sensitive determination of sarcosine in the concentration range of 0.01-5.0 mu M with the relative standard deviation of 3.49% (n = 5). The detection limit and quantification limit of the probe were determined to be 3.8 and 12 nM, respectively. The remarkable sensitivity and high selectivity of the method approved the sensor applicability in measurement of sarcosine content in urine samples. (C) 2021 Published by Elsevier B.V.

Automated summary

This study investigates the electrocatalytic activity of a NiMn2O4 binary metal oxide catalyst for the electroxidation of sarcosine. The carbon paste electrode modified with nano-NiMn2O4 showed unique catalytic activity, leading to a significant increase in oxidation current compared to the blank electrode. The method demonstrates remarkable sensitivity and high selectivity, making it potentially applicable for measuring sarcosine content in urine samples.