用直流等离子体喷射化学气相沉积(CVD)法制备掺硼金刚石(BDD)薄膜电极。通过扫描电镜(SEM)观察到薄膜表面分布均匀致密;霍尔测试仪检测薄膜的电阻率为0.023Ω·cm,载流子浓度为6.423×10^19cm-3;循环伏安法(CVa)测得其电极电势窗为3.4V;分析了浓度为10μmol/L的尿酸(UA)溶液在BDD电极表面的电化学响应,表明扫描速率的平方根与氧化峰电流呈线性关系。通过对比茜素黄、牛磺酸和L-半胱氨酸3种物质对BDD电极进行修饰,表明由L-半胱氨酸修饰BDD电极的电催化氧化能力最强;在浓度为1×101~1×10μmol/L范围内,浓度的对数与氧化峰电流呈线性关系,且检测限为1×10~mol/L。实验结果表明,20倍浓度的葡萄糖和抗坏血酸对UA的检测不构成影响。
Boron-doped diamond (BDD) thin film electrode was made in hydrogen-argon carbon source by direct current (DC) plasma jet chemical vapor deposition (CVD) method, and surface uniform and dense distribution can be seen by scanning electro microscopy (SEM). The resistivity is 0. 023 ·cm by the Hall test cytometry,and carrier concentration is 6. 423× 10^19 cm 3. The potential window for electrode is 3.4 V measured by cyclic voltammetry (CVa), and the boroh-doped diamond thin-film electrode's electrochemical response is analyzed at 10μmol/L of uric acid (UA). The scan rate is linear with oxidation peak current. In Alizarin yellow, taurine and L-cysteine modified BDD electrodes, the last one has the strongest electrocatalytic oxidation. The experimental results show that when the concentration of UA within the range of 1 × 10-7 - 1 × 10-4 mol/L, the logarithm of the concentrationt is linear with the oxidation peak current,and the detection limit is 1 ×10-8 mol/L. The 20-fold concentration of glucose and ascorbic acid does not affect the detection of uric acid.