Nafion/DNA/纳米铂复合膜修饰电极的制备及其应用于多巴胺的高灵敏高选择性测定

Preparation of a Nafion/DNA/Pt Nanoparticles Composite Film Modified Electrode and Its Application for Highly Selective and Sensitive Determination of Dopamine

纳米铂粒子(PtNPs)具有良好的生物相容性及高的催化性能,利用恒电位法将DNA生物分子电沉积在PtNPs修饰电极表面,得到一纳米结构的导电薄膜,极大地增大了电极的比表面积,结合Nafion的高选择性,制备了一种新型的Nafion/DNA/PtNPs复合膜修饰电极,研究了多巴胺(DA)在该修饰电极上的电化学行为,利用示差脉冲伏安法(DPV)对DA进行了定量分析.结果证明,该复合膜修饰电极大大提高了DA的电化学响应,在0.1 mol/L pH 7.0磷酸盐缓冲溶液(PBS)中,DA的示差脉冲伏安峰电流与其浓度在0.01～0.1μmol/L和0.1～6.0μmol/L两个范围内呈良好的线性关系,检出限可达3.3 nmol/L.此外,该修饰电极可以经受较高浓度抗坏血酸(AA)和尿酸(UA)的干扰,用于盐酸多巴胺注射液中DA含量的测定,结果满意.

A new nanocomposite film modified electrode was preparaed by electrodepositing DNA at the platinum nanopartieles（PtNPs） surface and then coating Nation on the composite film. This modified electrode （Nafion/DNA/ PtNPs ）was applied to detect dopamine （DA）by using differential pulse voltammetry（DPV）. The result indicates that the Nafion/DNA/PtNPs nanocomposite film has eleetrocatalytic effect on the oxidation of DA and results in an obvious enhancement of the current response. In 0.1 mol/L pH 7.0 phosphate buffer solution （ PBS ）, the DPV peak heights are linear with DA concentration in the range of 0.01-0.1 μmol/L and 0.1-6.0 μmol/L with the detection limit of 3.3 nmol/L（ S/N = 3 ）. In addition, the interferences of uric acid （UA） and ascorbie acid （AA） can be effectively diminished. Moreover,the Nafion/DNA/PtNPs/GCE was applied to the DA detection in dopamine hydrochloride injection with satisfied results.