Department of Analytical Chemistry, Complutense University of Madrid, 28040-Madrid, Spain.
Department of Organic Chemistry I, Faculty of Chemistry, Complutense University of Madrid, 28040-Madrid, Spain.
Analyst. 2016 Jun 20;141(13):4162-9. doi: 10.1039/c5an02640g.
A novel water-soluble graphene derivative was prepared from graphene oxide via a two-step modification approach. Graphene oxide was first functionalised with reactive epoxy groups by covalent modification with (3-glycidyloxypropyl)trimethoxysilane and further cross-linked with glycol chitosan. This graphene derivative was characterized using different microscopy and physicochemical methods and employed as a coating material for a glassy carbon electrode. The nanostructured surface was used as a support for the covalent immobilization of the enzyme laccase through cross-linking with glutaraldehyde. The enzyme electrode was tested for the amperometric detection of different phenolic compounds, which displayed excellent analytical behaviour toward catechol with a linear range of response from 200 nM to 15 μM, sensitivity of 93 mA M(-1) cm(-2), and low detection limit of 76 nM. The enzyme biosensor showed high stability when stored at 4 °C under dry conditions and was successfully employed to quantify the total phenolic compounds in commercial herbal tea samples.
一种新型的水溶性石墨烯衍生物是通过两步修饰方法从氧化石墨烯制备得到的。氧化石墨烯首先通过与（3-缩水甘油醚丙基）三甲氧基硅烷的共价修饰来官能化反应性环氧基团，然后与乙二醇壳聚糖进一步交联。使用不同的显微镜和物理化学方法对该石墨烯衍生物进行了表征，并用作玻璃碳电极的涂层材料。纳米结构表面被用作酶漆酶通过与戊二醛交联的共价固定的支撑物。通过安培法测试了酶电极对不同酚类化合物的检测，该电极对儿茶酚显示出优异的分析性能，响应线性范围为 200 nM 至 15 μM，灵敏度为 93 mA M(-1) cm(-2)，检测限低至 76 nM。当在 4°C 下干燥条件下储存时，酶生物传感器显示出高稳定性，并成功用于定量测定商业草药茶样品中的总酚类化合物。
