多壁碳纳米管固定化生物酶修饰电极检测杂色曲霉素的初步研究

The Primary Study on the Detection of Sterigmatocystin by Biologic Enzyme Electrode Modified with the Multiwall Carbon Nanotubes

杂色曲霉素 (ST)是一种致癌致畸的真菌毒素 ,已报道的检测ST的技术有TLC、HPLC、ELISA以及毒素基因的PCR检测技术。初步探索了酶生物传感器三电极系统对ST的电化学分析。在实验中 ,应用多壁碳纳米管作为分子识别元件ADTZ的固定化基质和传感器的电子传递体构建了Au工作电极 ,对ST进行CV和DPV分析 ,结果表明 :ST在 - 6 0 0mV位置有一明显的特征还原峰电位 ,线性检测范围是 8 32× 1 0 - 5～ 6 6 5 6× 1 0 - 5mg mL ,检测下限为8 32× 1 0 - 5mg mL ,响应时间 1 0s。

Sterigmatocystin (ST), the secondary metabolite of many kinds of filamentous fungi, is a potent carcinogen structu rally related to the aflatoxins (AFT). With similar chemical structure, sterigmatocystion behaves much the homogeneous properties to aflatoxins, both of these mycotoxins exhibit similar biological properties due to their bisfuranoid structure. Since the common, and even heavier pollution, found in foods and feeds stuff, sterigmatocystion is more harmful than aflatoxins. The reported detection methods of sterigmatocystion included the Thin layer Chromatography, the High Performance Liquid Chromatography, the Enzyme Linked Immunosorbant Assay and the PCR detection to the toxic gene, however studies about both easy and inexpensive electro chemical methods have not been found. Our previous studies had discovered that Sterigmatocystin (ST) exist similar sensitivity towards aflatoxin detoxifizyme (ADTZ), which we had isolated from a fungus, as aflatoxin does. In this work, the preliminary study on electrochemical analysis and determination of ST with triplet electrode enzyme biosensor system (Ag/AgCl as the reference electrode,Pt and Au as the pair and work electrode, respectively) was carried out. Multiwall carbon nanotube (MWNT) had been used to increase the electron transportation on electrode. In the research, the Au electrode was modified by MWNT immobilized ADTZ, and then the voltammertric behavior of ST was studied by means of cyclic voltammogram analysis and different pulse analysis. Autoprobe CP Research Atomic Force Microscope and TECNAI 10 Transmission Electron Microscope,had been used to detect the MWNT as well as the surface of MWNT modified ADTZ. The voltammertric behavior of ST was studied by means of cyclic voltammogram analysis and different pulse analysis. The results show that the red ox peak potential of ST is at the point of -600mV, the linear detection range is from 8 32×10 -5 to 66 56×10 -5 mg/mL, the detection limit is at 8 32×10 -5 mg/mL, and the response time is 10 seconds. This study provided a good basic work for further research.