PDF(Pubmed)
Abstract：
Simple and sensitive determination of total antioxidant capacity (TAC) in food samples is highly desirable. In this work, an electrochemical platform was established based on a silica nanochannel film (SNF)-modified electrode, facilitating fast and highly sensitive analysis of TAC in colored food samples. SNF was grown on low-cost and readily available tin indium oxide (ITO) electrode. Fe3+-phenanthroline complex-Fe(III)(phen)3 was applied as the probe, and underwent chemical reduction to form Fe2+-phenanthroline complex-Fe(II)(phen)3 in the presence of antioxidants. Utilizing an oxidative voltage of +1 V, chronoamperometry was employed to measure the current generated by the electrochemical oxidation of Fe(II)(phen)3, allowing for the assessment of antioxidants. As the negatively charged SNF displayed remarkable enrichment towards positively charged Fe(II)(phen)3, the sensitivity of detection can be significantly improved. When Trolox was employed as the standard antioxidant, the electrochemical sensor demonstrated a linear detection range from 0.01 μM to 1 μM and from 1 μM to 1000 μM, with a limit of detection (LOD) of 3.9 nM. The detection performance is better that that of the conventional colorimetric method with a linear de range from 1 μM to 40 μM. Owing to the anti-interfering ability of nanochannels, direct determination of TAC in colored samples including coffee, tea, and edible oils was realized.
摘要：
简单而灵敏地测定食品样品中的总抗氧化能力(TAC)是非常理想的。在这项工作中,建立了基于二氧化硅纳米通道薄膜(SNF)修饰电极的电化学平台,促进有色食品样品中TAC的快速和高灵敏度分析。SNF在低成本且易于获得的氧化铟锡（ITO）电极上生长。Fe3+-菲咯啉配合物-Fe(III)(phen)3作为探针,并在抗氧化剂存在下进行化学还原以形成Fe2-菲咯啉络合物-Fe（II）（phen）3。利用+1V的氧化电压，采用计时电流法测量Fe（II）（phen）3的电化学氧化产生的电流，从而可以评估抗氧化剂。由于带负电荷的SNF对带正电荷的Fe（II）（phen）3显示出显着的富集，因此可以显着提高检测的灵敏度。当Trolox被用作标准抗氧化剂时，电化学传感器的线性检测范围从0.01μM到1μM，从1μM到1000μM，检测限(LOD)为3.9nM。检测性能优于常规比色法，线性范围为1μM至40μM。由于纳米通道的抗干扰能力，直接测定包括咖啡在内的有色样品中的TAC，茶，实现了食用油。
