丙烯酰胺是一种神经毒素,具有潜在致癌性。丙烯酰胺分子可以和血红蛋白结构中N-末端缬氨酸的α-NH2形成共价化合物引起电极钝化,其含量不同,钝化程度也不同。基于此原理,本研究将多壁碳纳米管/血红蛋白/壳聚糖修饰的生物传感器用于油炸食品中丙烯酰胺的检测。利用差分伏安脉冲法对油炸食品中丙烯酰胺进行定量分析并对条件优化,多壁碳纳米管修饰量为10μg/cm^2、支持电解质溶液为0.1 mol/L的PBS溶液(p H=7.4,含5×10^-3 mol/L K4[Fe(CN)6],0.1 mol/L Na Cl),其中K4[Fe(CN)6]作为氧化还原探针,电位增量0.008 V、脉冲幅度0.05 V、脉冲宽度0.1 V、脉冲间隔0.1 s,丙烯酰胺线性检测范围3.0×10^-8 mol/L-3.0×10^-7 mol/L,最低检测限(S/N=3)为1.2×10^-8 mol/L。与高效液相色谱法相比,该法具有简便、快速、准确、样品预处理简单、无需衍生化等优点。
Acrylamide is a neurotoxin and a potential carcinogen. Hemoglobin(Hb) biosensor passivation can be achieved by the formation of a covalent compound by acrylamide with the-NH2 group of the N-terminal valine of hemoglobin. Different concentrations of acrylamide produce different degrees of passivation. Based on this principle, hemoglobin biosensors were prepared by immobilizing multi-wall carbon nanotubes(MWCNTs) and Hb in a chitosan film on the surface of glassy carbon electrodes and these were used for the detection of acrylamide in fried food. The optimum analysis conditions for the detection of acrylamide in fried food by differential pulse voltammetry(DPV) was determined as follows: pulse increment 0.008 V, pulse amplitude 0.05 V, pulse width 0.1 V, pulse interval 0.1 s. The oxidative-reductive detector consisted of 10 μg/cm^2 MWCNTs and the supporting electrolytes were 0.1 mol/L PBS(p H 7.4), 0.1 mol/L Na Cl and 5×10^-3 mol/L potassium ferrocyanide. The linear range of response was from 3.0×10^-8 mol/L to 3.0×10^-7 mol/L and the detection limit was estimated as 1.2×10^-8 mol/L, taking into account a signal-to-noise ratio of 3. The developed method is practical in the determination of acrylamide in fried foods, with the advantages of simplicity, rapidity, sensitivity, and accuracy over the standard high-pressure liquid chromatography method.