Rapid and selective diagnose of Sarcosine in urine samples as prostate cancer biomarker by mesoporous imprinted polymeric nanobeads modified electrode

The presence of sarcosine (SAR) in the human urine was recently suggested as a promising biomarker for prostate cancer (PCa) diagnostics. In this work, we have developed the electrochemical methods for selective determination of sarcosine (SAR) in urine samples, based on the modification of the carbon paste electrode (CPE) using uniform nano-scaled molecularly imprinted polymer (MIP). The uniform MIP nanobeads were prepared by a simple sol-gel method, using methacrylic acid as a functional monomer in a mixture of acetonitrile/water, as porogen. The usual problems related to the imprinting of the biologically polar compounds, especially; amino acids were solved by performance the present approach. After characterization, the as-synthesized MIP particles were used as chemical modifier for the construction of a modified CPE. The electrochemical behaviors and quantitative analysis of SAR were evaluated on MIP@CPE by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The modified sensor exhibits reproducible voltammetric responses with a relative standard deviation of 2.1 % and a highly selective affinity toward SAR in the presence of other co-existing and/or possible interferes. Under the optimized conditions, the peak current was found to be proportional to SAR concentration over a range of 5.0 mu M-1.1 mM, with an excellent correlation coefficient (R-2) of 0.9998 and an acceptable limit of detection (LOD; 0.38 mu M). The practical application of the designed sensor for PCa diagnosis was evaluated by its possible applicability for the determination of SAR in urine samples of the healthy human as well as the cancer patients.