Sensitive Voltammetric Sensor for Amaranth Based on Ordered Mesoporous Carbon

Abstract

Abstract A voltammetric sensor for the determination of amaranth was constructed based on glassy carbon electrode (GCE) modified with ordered mesoporous carbon (OMC) by utilizing sucrose as carbon source to get the ordered mesoporous carbon (OMC) and a template of SBA-15 was prepared by using P123 (EO 20 –PO 70 EO 20 ) as the surfactant and tetraethylorthosilicate (TEOS) as the silica source. 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. Compared with the bare GCE and carbon nanotubes/GCE (CNT/GCE), the OMC/GCE exhibited larger electroactive surface area, and 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. By using the differential pulse voltammetry (DPV) for determination of amaranth, the peak current of was found to be linear with amaranth concentration in the range from 1.0 × 10 −7 M to 3.0 × 10 −6 M with a lower detection limit of 3.2 × 10 −8 M ( S/N = 3). Satisfactory results were obtained in the analysis of wine samples by using the prepared sensor.