基于石墨烯-纳米金-丝素水凝胶的高灵敏有机相酶电极检测呋喃丹

摘要

采用改进的Hummers法制备了氧化石墨烯(GO)，用微波辅助丝素还原法制备了丝素还原石墨烯(SF-GR)，并用红外（FT-IR）、紫外（UV-vis）和透射电镜（TEM）对SF-GR进行了表征。然后以丝素同时原位还原的石墨烯-纳米金复合水凝胶包埋酪氨酸酶(Tyr)制备了新型的有机相酶电极(SF-GR-NanoAu-Tyr/GCE)，在纯氯仿中对呋喃丹进行了检测。结果表明，在有机相中，丝素水凝胶能较好的保持酪氨酸酶的生物活性，GR和NanoAu促进了电子在电极界面上以及水凝胶内部的电子传递，提高了酶电极的灵敏性。在没有另外添加水或者缓冲液的情况下，酪氨酸酶的抑制率与浓度范围为1.0×10-8~1.0×10-12 mol/L的呋喃丹呈线性关系，检测限为8.0×10-13 mol/L。该有机相酶电极制备简单，检测快速，灵敏度高，适合于有机溶剂中微量农药的定量检测。%Graphene oxide was prepared by the method of modified Hummers. Silk-reduced-graphene (SF-GR) was prepared using microwave-assisted silk fibroin reduction synthesis method. TEM, FT-IR and UV-vis were uti-lized to characterize SF-GR. Then, a novel highly sensitive enzymatic inhibition organic phase enzyme electrode (OPEE) was fabricated by enwrapping tyrosinase in graphene-gold nanoparticles-silk fibroin hydrogel. The SF hy-drogel provided a necessary amount of water and a biocompatible microenvironment around the enzyme molecule to stabilize its biological activity and effectively prevented its inactivation by inhibitors such as pesticides. Under op-timized conditions, the inhibition percentage of carbofuran was proportional to its concentration in the range of 1.0 × 10-8 to 1.0 × 10-12 mol/L with a detection limit of 8.0 × 10-13 mol/L. Thus, the highly sensitive OPEE is a promis-ing new tool for pesticide analysis in organic solvents.