Rapid and accurate detection of proteins in biological fluids is increasingly required in the biomedical environment. Actually, it is performed with conventional techniques, which are generally run by robotized platforms at centralized laboratories. In this work, molecular dynamics calculations and an experimental procedure were conducted to set up electrochemical sensors based on polypyrrol (PPy) molecular imprinted polymers (MIP) for proteins detection. Here, prostate-specific antigen (PSA) was selected as a template model. Computational calculations indicate that for any PPy conformation and any amino-acid location in the protein, PSA molecules remain strongly inserted in the PPy polymer without biological alterations. One from possible orientations, appeared to be most probable as it presents the lowest absorption energy (-363 kcal mol-1) and largest contact area (4034.1 Å2). The device was then elaborated by in situ electropolymerization of PPy films. MIP's thickness and extraction duration were optimized by chronoamperometry. Square wave voltammetry technique was investigated for PSA detection in standard solution in the concentration range of 3x10 -8 ng.ml-1- 300 ng ml-1. According to the Hill equation, the equilibrium dissociation constant Kdbetween PSA and its imprint was estimated at Kd = (1.02 ± 0.54) × 10-14 M, confirming the strong binding between the designed MIP and the protein as predicted by the computational study. PSA concentration values directly measured in 35 human serum samples were found closely correlated to those measured by the ELISA technique. The promising fast and low-cost sensor might be used successfully for proteins detection at low concentrations with high selectivity and reproducibility.

中文翻译：

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使用基于MIP的传感器进行蛋白质检测的计算方法和电化学测量。

在生物医学环境中，越来越需要快速，准确地检测生物流体中的蛋白质。实际上，它是通过常规技术执行的，该技术通常由集中实验室的机器人平台运行。在这项工作中，进行了分子动力学计算和实验程序，以建立基于聚吡咯（PPy）分子印迹聚合物（MIP）的电化学传感器来检测蛋白质。在此，选择前列腺特异性抗原（PSA）作为模板模型。计算计算表明，对于蛋白质中的任何PPy构象和任何氨基酸位置，PSA分子始终牢固插入PPy聚合物中，而没有生物学改变。一种来自可能的方向，似乎最有可能，因为它具有最低的吸收能量（-363 kcal mol-1）和最大的接触面积（4034.1Å2）。然后通过原位电聚合PPy膜来制作该器件。MIP的厚度和提取持续时间通过计时安培法进行了优化。研究了方波伏安法用于标准溶液中浓度范围为3x10 -8 ng.ml-1- 300 ng ml-1的PSA检测。根据希尔方程，PSA及其印迹之间的平衡解离常数Kd估计为Kd =（1.02±0.54）×10-14 M，从而证实了设计MIP与蛋白质之间的牢固结合，正如计算研究所预测的那样。发现在35个人血清样品中直接测量的PSA浓度值与通过ELISA技术测得的PSA浓度值紧密相关。