Department of Industrial Chemical Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, José Gutierrez Abascal, 2, Madrid 28006, Spain.
Department of Industrial Chemical Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, José Gutierrez Abascal, 2, Madrid 28006, Spain.
Mater Sci Eng C Mater Biol Appl. 2020 Apr;109:110602. doi: 10.1016/j.msec.2019.110602. Epub 2019 Dec 26.
Herein, a new sensor based on screen-printed carbon electrodes covalently modified with self-assembled gold-decorated-polydopamine nanospheres (Au-PDNs) is reported. The sensor was applied to the simultaneous determination of the biologically significant molecules ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (TR). The Au-PDNs were anchored to gold nanoparticles electrodeposited onto the bare electrodes via cysteamine-glutaraldehyde bridges, and were characterized by scanning and transmission electron microscopies. The stepwise fabrication of the electrodes and their electrochemical responses were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. The response of the new device to these analytes is pH-dependent, which allows selecting the best working conditions as a function of the sample characteristics. At pH values of 3.0 and 8.0, it was possible to determine simultaneously AA, UA and TR in presence of DA, and DA, UA and TR in presence of AA respectively, with very wide linear ranges and high sensitivities. The simultaneous determination of AA, DA, UA and TR was possible at pH 6.0 with competitive sensitivities in two consecutive linear ranges, between 10-80 μM and 80-240 μM; 1-160 μM and 160-350 μM; 10-120 μM and 120-350 μM; and 1-160 μM and 160-280 μM, respectively. The obtained limits of detection were 0.2 nM, 0.1 nM, 0.1 nM and 0.1 nM, respectively.
本文报道了一种基于金修饰的聚多巴胺纳米球共价修饰的丝网印刷碳电极的新型传感器。该传感器用于同时测定具有生物意义的分子抗坏血酸 (AA)、多巴胺 (DA)、尿酸 (UA) 和色氨酸 (TR)。通过半胱氨酸-戊二醛桥将 Au-PDNs 固定在金纳米粒子上电沉积到裸电极上，并用扫描和透射电子显微镜进行了表征。通过循环伏安法、电化学阻抗谱和差分脉冲伏安法对电极的逐步制备及其电化学响应进行了评价。新器件对这些分析物的响应是 pH 依赖性的，这允许根据样品特性选择最佳工作条件。在 pH 值为 3.0 和 8.0 时，可以分别在存在 DA 的情况下同时测定 AA、UA 和 TR，以及在存在 AA 的情况下同时测定 DA、UA 和 TR，具有非常宽的线性范围和高灵敏度。在 pH 6.0 时，可以用竞争灵敏度在两个连续的线性范围内同时测定 AA、DA、UA 和 TR，范围分别为 10-80 μM 和 80-240 μM；1-160 μM 和 160-350 μM；10-120 μM 和 120-350 μM；以及 1-160 μM 和 160-280 μM。分别获得的检测限为 0.2 nM、0.1 nM、0.1 nM 和 0.1 nM。
