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以铂微电极(PME)作为工作电极,简化三电极为两电极系统,利用多壁碳纳米管(MWCNTs)具有高比表面积、高催化活性、显著增强响应电流的特性,将分散于N,N-二甲基甲酰胺(DMF)的羧基化MWCNTs修饰于自制PME表面,建立一种新型检测Vc的生物传感器。与常见的宏观电极相比,羧基化MWCNTs修饰的铂丝微电极(DMF/carboxyl/MWCNTs/PME)检测Vc,降低了Vc的氧化电位,增大了氧化峰电流值,提高了电子转移速率,并展现出良好的灵敏度及稳定性。通过一系列检测条件及修饰材料的优化,将DMF/carboxyl/MWCNTs/PME应用于Vc标准液检测中,测得Vc浓度在(1.0×10~(-4)~2.0×10~(-1))mol/L内与氧化电流值呈线性关系,且线性方程为:I(A)=4.19711×10~(-8)+1.27293×10~(-5)C(mol/L),检测限为1.0×10~(-5) mol/L(S/N=3)。DMF/carboxyl/MWCNTs/PME检测实际样品的回收率为97%~113%,验证了DMF/carboxyl/MWCNTs/PME快速检测食品中Vc的可行性。
Using platinum microelectrode (PME) as the working electrode and three electrodes as a two-electrode system, the MWCNTs are characterized by their high specific surface area, high catalytic activity and significantly enhanced response current. They are dispersed in N, N - Dimethylformamide (DMF) carboxylation MWCNTs modified homemade PME surface, the establishment of a new Vc-based biosensor. Compared with common macroscopic electrode, Vc decreased with the decrease of Vc oxidation potential and increased the oxidation peak current value, and increased the electron transfer rate by using carboxylated MWCNTs modified platinum wire microelectrode (DMF / carboxyl / MWCNTs / PME) And show a good sensitivity and stability. DMF / carboxyl / MWCNTs / PME was applied to the detection of Vc standard solution through a series of testing conditions and optimization of the modified materials. The Vc concentration was measured in the range of (1.0 × 10 -4 ~ 2.0 × 10 -1) ) mol / L was linear with the oxidation current. The linear equation was: I (A) = 4.19711 × 10 -8 + 1.27293 × 10 -5 mol / L, the detection limit was 1.0 × 10 ~ (-5) mol / L (S / N = 3). The recovery of real samples from DMF / carboxyl / MWCNTs / PME was 97% -113%, which verified the feasibility of DMF / carboxyl / MWCNTs / PME for rapid determination of Vc in food.