Abstract

The measurement of total antioxidant capacity (TAC) indicating the cooperative action of all antioxidants in a complex sample is an important analytical challenge. A novel green silver nanoparticle-based antioxidant capacity (GSNP-AC) method using carob extract was designed for TAC measurement. Green synthesis of nanoparticles has various advantages such as environmentally friendliness, reliability, sustainability and fast production. In the presence of silver seeds formed with carob extract, Ag⁺ is reduced to spherical silver nanoparticles (SNPs) with antioxidants, resulting in enlarged particles with a symmetric surface plasmon resonance (SPR) absorption band at 434 nm. The SPR of SNPs allowed quantification of antioxidants (i.e., increase in SPR absorbance being correlated to antioxidant concentration), and the GSNP-AC method gave a linear response over a wide concentration range of antioxidants. The molar absorptivity and LOD for trolox were 11700 L mol⁻¹ cm⁻¹ and 0.31 µM, respectively. The proposed method was validated in terms of concentration-dependent linear response, additivity of absorbances, precision and accuracy. The results obtained with the proposed method for standard antioxidants, synthetic mixtures and real sample extracts were correlated with those of the traditional CUPRAC method. This green synthesized silver nanoparticle-based TAC method showed simple, rapid, cost-effective, and eco-friendly superiorities over similar other nanoparticle-based assays.

Graphic Abstract

中文翻译：

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用角豆提取物开发绿色合成的基于银纳米粒子的抗氧化剂能力方法

摘要

指示复杂样品中所有抗氧化剂协同作用的总抗氧化剂容量（TAC）的测量是一项重要的分析挑战。设计了一种新的基于角豆提取物的基于绿色银纳米粒子的抗氧化能力（GSNP-AC）方法，用于TAC测量。纳米颗粒的绿色合成具有多种优势，例如环保，可靠性，可持续性和快速生产。在有角豆提取物银⁺形成的银种子存在下被抗氧化剂还原为球形银纳米粒子（SNP），导致粒子在434 nm处具有对称的表面等离振子共振（SPR）吸收带。SNP的SPR允许定量抗氧化剂（即SPR吸光度的增加与抗氧化剂浓度相关），而GSNP-AC方法在较宽的抗氧化剂浓度范围内给出线性响应。trolox的摩尔吸收率和LOD为11700 L mol ^-1  cm ^-1和0.31 µM。所提出的方法在浓度依赖性线性响应，吸光度的加和性，精度和准确性方面得到了验证。所建议的标准抗氧化剂，合成混合物和真实样品提取物的方法获得的结果与传统CUPRAC方法的结果相关。这种基于绿色合成银纳米颗粒的TAC方法显示出比其他基于纳米颗粒的其他类似方法简单，快速，具有成本效益和生态友好的优势。

图形摘要