以碳纳米管为支撑电沉积制备高电活性与电催化性能的六氰合铁酸钴纳米多孔薄膜

摘要

以碳纳米管(MWNTs)修饰的碳糊电极为基底电极,通过电沉积方法制备了六氰合铁酸钴(CoHCF)纳米多孔生物传感平台.考察了MWNTs对CoHCF沉积的影响,优化了CoHCF沉积的各种实验条件(0.5mol/L KCl,1mmol/L CoCl2和0.9mmol/L K3Fe(CN)6混合溶液,在循环伏安电压范围0～1.1 V内扫20圈,扫速100 mV/s),借助循环伏安法、交流阻抗法和扫描电镜法对修饰电极进行了表征.由于MWNTs的支撑作用,电沉积得到的CoHCF呈现出多孔结构和良好的电化学稳定性.具有纳米多孔结构的MWNTs - CoHCF薄膜能有效地促进生物小分子在电极上的电子交换,维生素B2在纳米多孔CoHCF/MWNTs上具有优异的氧化还原行为,其测定线性范围为1.2×10-7～2.6×10-7 mol/L,检出限为8.9×10-8 mol/L.%A cobalt hexacyanoferrate (CoHCF) film was successfully electro-deposited on functional-ized multi-wall carbon nanotubes(MWNTs) modified glassy carbon electrodes by scanning the potential between 0 V and 1. 1 V at a scan rate of 100 mV/s for 20 consecutive scans in an aqueous electrolyte of 0.5 mol/L KC1, 1 mmol/L CoCl2 and 0.9 mmol/L K3Fe(CN)6. The modified electrodes (MWNTs -CoHCF/GCE) were characterized by scanning electron microscope and cyclic voltammet-ric methods. It was found that the CoHCF film was covered with the MWNTs. The MWNTs - CoHCF/GCE presented a nanoporous structure with an excellent electrochemical stability, which showed a favorable electron transfer kinetics. The cyclic voltammetric experiment showed that the MWNTs -CoHCF/GCE had a favorable electrochemical activity for the oxidation of vitamin B2 ( VB2 ) , and the peak current was linear over VB2 concentration in the range of 1. 2 × 10 -7 -2. 6 × 10 -7 mol/L with a detection limit( S/N = 3 ) of 8.9 × 10 -8 mol/L.