聚合物纳米组装体修饰丝网印刷电极构建过氧化氢传感器

通过在聚合物结构中同时引入生物亲和单体和电活性单体,使得聚合物组装体在修饰丝网印刷电极时兼具提高比表面积、保持酶活和促进电子转移功能,从而发展了一种简单、高效构建电化学传感器的方法。 以苯乙烯(St)、丙烯酸(AA)、N-乙烯基咔唑(VCz)和甲基丙烯酸二甲氨基乙酯(DMAEMA)为单体自由基聚合合成双亲性无规共聚物Poly(St-co-AA-co-VCz-co-DMAEMA)(PSACD),将聚合物在选择性混合溶剂DMF/H₂O中自组装得到聚合物纳米粒子PSACD NPs。 利用纳米粒度分析仪、扫描电子显微镜(SEM)对其进行表征。 依次将PSACD NPs水分散液、辣根过氧化物酶(HRP)溶液和全氟磺酸-聚四氟乙烯共聚物(Nafion,NF)溶液滴涂在丝网印刷碳电极(SPCE)上,制备得到过氧化氢生物传感器。 通过计时电流法对传感器性能进行研究,表明该传感器对H₂O₂在0.02~7.48 mmol/L有良好的线性响应,且响应时间短(<2 s),具有良好的选择性和稳定性。

Hydrogen Peroxide Sensor Based on a Polymeric Self-assembled Nanoparticles-Modified Screen-Printed Electrode

We report on a facile and efficient construction of electrochemical biosensors by modifying the screen printed carbon electrodes(SPCE)with multifunctional polymeric nanoparticles.An amphiphilic random copolymer,poly(St-co-AA-co-VCz-co-DMAEMA)(PSACD),was first synthesized using styrene(St),acrylic acid(AA),N-vinylcarbazole(VCz)and dimethylaminoethyl methacrylate(DMAEMA)as hydrophobic,hydrophilic,electroactive and enzymatic compatible monomers,respectively.The polymeric nanoparticles(PSACD NPs)were then prepared through self-assembly of polymers in a selective solvent mixture of DMF/H2O.The obtained PSACD NPs were characterized by particle size analyzer and scanning electron microscope(SEM),and were used to fabricate the hydrogen peroxide(H2O2)biosensor with the functions of improving the specific surface areas,providing a suitable microenvironment for keeping the enzyme activity,and accelerating the electron transfer between enzymes and the electrodes.Specifically,the SPCE was successively modified by PSACD NPs suspensions,horseradish peroxidase(HRP)solution and perfluorosulfonic acid-PTFE copolymer(Nafion)solution.The properties of the proposed electrochemical biosensor were studied via an amperometric detection method.The results show that the biosensor has a short response time(less than 2 s)and a linear increasing response current with the concentration of H2O2 increasing from 0.02 to 7.48 mmol/L.The biosensor also has nice stability,good selectivity and excellent anti-interference performance.