Mathiyarasu J, Senthilkumar S, Phani K L N, Yegnaraman V
Electrodics and Electrocatalysis Division, Central Electrochemical Research Institute, Karaikudi 630006, India.
J Nanosci Nanotechnol. 2007 Jun;7(6):2206-10. doi: 10.1166/jnn.2007.796.
In this work, conducting polymer impregnated gold nanoparticles are synthesized through a sequence of chemical and electrochemical routes. The nanocomposite film is characterized using UV-vis, FTIR spectroscopy, and SEM techniques to study the formation of oxidized PEDOT and Au0. The advantages of these films are demonstrated for sensing biologically important compounds such as dopamine and uric acid in presence of excess ascorbic acid, one of the major interferants in the detection of DA and UA (mimicking the physiological conditions), with superior selectivity and sensitivity when compared to the polymer film alone. Simultaneous determination is realized at 115 mV and 246 mV for DA and UA, respectively. The PEDOT matrix is recognized to be responsible for the peak separation (selectivity) while also favouring catalytic oxidation of the above compounds and the nanometer-sized gold particles allow nanomolar sensing of DA and UA (sensitivity). Thus, it is possible to detect nanomolar levels of DA and UA in presence of excess of AA. The combined effect of Au nanoparticles and the PEDOT matrix is rationalized that the Aunano surrounded by a "hydrophobic sheath (PEDOT)" tending to reside within these hydrophobic regions of PEDOT, thus favouring the selectivity and sensitivity of the DA/UA detection. This new generation of nanocomposites is expected to enhance the value of electroanalytical techniques, as it is possible to tune their properties suiting the analytical needs.
在这项工作中，通过一系列化学和电化学途径合成了导电聚合物浸渍的金纳米颗粒。使用紫外可见光谱、傅里叶变换红外光谱和扫描电子显微镜技术对纳米复合膜进行表征，以研究氧化聚3,4-乙撑二氧噻吩（PEDOT）和零价金（Au⁰）的形成。这些薄膜的优势体现在，在存在过量抗坏血酸（检测多巴胺（DA）和尿酸（UA）时的主要干扰物之一，模拟生理条件）的情况下，对DA和UA等生物重要化合物具有传感能力，与单独的聚合物薄膜相比，具有更高的选择性和灵敏度。DA和UA分别在115 mV和246 mV实现同时测定。PEDOT基质被认为是造成峰分离（选择性）的原因，同时也有利于上述化合物的催化氧化，而纳米尺寸的金颗粒使对DA和UA的传感达到纳摩尔级（灵敏度）。因此，在存在过量抗坏血酸的情况下，有可能检测到纳摩尔水平的DA和UA。金纳米颗粒和PEDOT基质的综合作用被解释为，被“疏水鞘层（PEDOT）”包围的金纳米颗粒倾向于存在于PEDOT的这些疏水区域内，从而有利于DA/UA检测的选择性和灵敏度。这种新一代的纳米复合材料有望提升电分析技术的价值，因为可以根据分析需求调整其性能。
