Oxidative stress is considered as an imbalance of reactive species over antioxidants, leading to diseases and cell death. Various methods have been developed to determine the antioxidant potential of natural or synthetic compounds based on the ability to scavenge free radicals. However, most of them lack biological relevance. Here, a gold-based self-assembled monolayer (SAM) was compared with a gold-supported lipid bilayer as models for the mammalian cell membrane to evaluate the free radical scavenging activity of different antioxidants. The oxidative damage induced by reactive species was verified by cyclic and differential pulse voltammetry and measured by the increase of electrochemical peak current of a redox probe. Trolox, caffeic acid (CA), epigallocatechin gallate (EGCG), ascorbic acid (AA), and ferulic acid (FA) were used as model antioxidants. The change in the decrease of the electrochemical signal reflecting oxidative membrane damage confirms the expected protective role. Both model systems showed similar efficacies of each antioxidant, the achieved order of radical scavenging potential is as follows: Trolox > CA > EGCG > AA > FA. The results showed that the electrochemical assay with SAM-modified electrodes is a stable and powerful tool to estimate qualitatively the antioxidative activity of a compound with respect to cell membrane protection against biologically relevant reactive species.

氧化应激被认为是反应性物质与抗氧化剂之间的不平衡，从而导致疾病和细胞死亡。基于清除自由基的能力，已经开发出各种方法来确定天然或合成化合物的抗氧化剂潜力。但是，它们中的大多数缺乏生物学意义。在这里，将金基自组装单分子膜（SAM）与金支持脂质双分子膜作为哺乳动物细胞膜的模型进行比较，以评估不同抗氧化剂的自由基清除活性。通过循环和差分脉冲伏安法验证了由反应性物质引起的氧化损伤，并通过氧化还原探针的电化学峰值电流的增加来测量。Trolox，咖啡酸（CA），表没食子儿茶素没食子酸酯（EGCG），抗坏血酸（AA），和阿魏酸（FA）用作模型抗氧化剂。反映氧化膜损伤的电化学信号减少的变化证实了预期的保护作用。两种模型系统均显示出每种抗氧化剂的相似功效，自由基清除潜力的实现顺序如下：Trolox> CA> EGCG> AA> FA。结果表明，使用SAM修饰电极进行的电化学测定是一种稳定而强大的工具，可以定性地评估化合物对细胞膜针对生物学相关反应物种的保护的抗氧化活性。自由基清除潜力的实现顺序如下：Trolox> CA> EGCG> AA> FA。结果表明，使用SAM修饰电极进行的电化学测定是一种稳定而强大的工具，可以定性地评估化合物对细胞膜针对生物相关反应物种的保护的抗氧化活性。自由基清除潜力的实现顺序如下：Trolox> CA> EGCG> AA> FA。结果表明，使用SAM修饰电极进行的电化学测定是一种稳定而强大的工具，可以定性地评估化合物对细胞膜针对生物学相关反应物种的保护的抗氧化活性。