以P123(EO20-PO70EO20)为表面活性剂、正硅酸乙酯为硅源,制备了介孔硅模板SBA-15,以蔗糖为碳源,制备了有序介孔碳(OMC)并将其修饰到玻碳电极(GCE)表面,构建了苋菜红伏安传感器.扫描电镜、透射电镜、小角X-射线衍射仪和氮气吸附等表征方法表明,OMC具有较高的比表面积、高度有序的六方结构和较狭窄的规则孔道分布.相比于GCE和碳纳米管修饰GCE(CNT/GCE),OMC/GCE表现出较高的电化学活性.中性介质中OMC/GCE对苋菜红的氧化显示较高的电催化活性.经过一系列的优化条件实验,如富集电位,pH值和富集时间.在电位为0.72 V条件下,传感器峰电流与苋菜红的浓度在1.0×10-7~3.0×10-6mol/L范围内呈线性关系;检出限为3.2×10-8 mol/L(S/N=3).OMC/GCE用于检测红酒样品中的苋菜红,获得满意结果.
By using P123 (EO2o-PO70EO20) as the surfactant and tetraethylorthosilicate (TEOS) as the silica source, a template of SBA-15 was prepared. By utilizing sucrose as carbon source to get the ordered mesoporous carbon (OMC), a voltammetric sensor for amaranth was constructed based on glassy carbon electrode (GCE) modified with OMC. The scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle X-ray diffraction (XRD) and nitrogen adsorption-desorption isotherms displayed the highly ordered hexagonal pores and narrow mesopore size distribution of OMC. In comparison with the bare GCE and carbon nanotubes/GCE, the OMC/GCE exhibited larger electroactive surface area. OMC/GCE exhibited an enhanced electrochemical response toward the oxidation of amaranth in the neutral solution. In addition, some experimental parameters such as accumulation potential, pH values and accumulation time were optimized. The results showed that the peak current increased linearly with the concentration of amaranth from 1.0 × 10-7 mol/L to 3.0 × 104 mol/L at 0.72 V and the detection limit was 3.2× 104 mol/L(S/N= 3 ). The prepared sensor was successfully used in real samples analysis with satisfying results.