钯/聚苯胺纳米多层膜的制备及对抗坏血酸和多巴胺的催化氧化

采用脉冲电位法(PPSM)结合聚苯胺(PANI)的层层自组装制备了Pd/PANI交替沉积纳米多层膜,并用于抗坏血酸(AA)和多巴胺(DA)的检测.实验发现,多层膜结构形貌及催化性能受前躯体K2PdCl6浓度、脉冲条件及膜厚度等影响.当K2PdCl6浓度为2×10-3mol/L,阴极脉冲电位为-0.3 V,阶跃次数为17时,5层Pd/PANI修饰玻碳电极对AA和DA的催化性能最佳;在0.1 mol/L磷酸盐缓冲液中,AA和DA的氧化峰明显分离ΔEp(AA,DA)=160 mV],其峰电流与浓度分别在5×10-5～4×10-4和4×10-5～1×10-4mol/L范围内呈较好线性关系,实现了对AA和DA的同时测定.该修饰电极具有良好的抗干扰性和稳定性.

Preparation of Palladium Nanoparticle/Polyaniline Multilayer Films for the Determination of Dopamine and Ascorbic Acid

Using K2PdCl6 as precursor and polyaniline(PANI) as the intermediate layer, a Pd/PANI multilayer nanocomposite film was fabricated on glassy carbon electrode(GCE) by pulse potentiostatic method(PPSM) combining with layer by layer(LBL) assembly technique for the electrochemical detection of ascorbic acid(AA) and dopamine(DA). Compared with the Pd nanoparticles only film, the Pd/PANI composite films show good particle dispersion and uniformity on the electrode. The morphology of the multilayer film and the catalytic performance of the as-prepared Pd/PANI modified electrode were dependent on K2PdCl6 concentration, pulse parameters and film thickness. With 2×10-3 mol/L K2PdCl6 as precursor, -0.3 V pulse potential and 17 pulse steps, the obtained Pd/PANI electrode with 5 bilayers exhibits the optimal catalytic ability for the oxidation of DA and AA in 0.1 mol/L(pH=7.0) phosphate buffer solution. With differential pulse voltammetry(DPV) technique, the Pd/PANI modified electrode was used for the simultaneous detection of AA and DA with a peak-to-peak separation of 160 mV, and the linear analytical curves were obtained in the range of 5×10-5—4×10-4 mol/L and 4×10-5—1×10-4 mol/L for AA and DA, respectively. The resultant Pd/PANI multilayer electrode shows good stability and anti-interference ability with the possibility for the biological sample detection.