State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, PR China.
Analyst. 2011 Feb 21;136(4):769-74. doi: 10.1039/c0an00725k. Epub 2010 Dec 13.
A novel method based on surface-enhanced Raman scattering (SERS) was developed to estimate the antioxidant activity of antioxidants by using self-assembled three-dimensionally (3D) ordered gold nanoparticles (GNPs) precursor composite (SiO(2)/GNPs) arrays as nanoprobes. H(2)O(2) could reduce AuCl(4)(-) to Au(0) which deposited onto the surface of the SiO(2)/GNPs arrays and enlarged the GNPs. As the concentration of H(2)O(2) increased, the surface coverage of the resultant gold on the silica cores increased accordingly until continuous gold nanoshells (GNSs) were formed. The change of the intensities of the SERS spectra correlated well with H(2)O(2) concentration which indicated that this SiO(2)/GNPs array was a potential SERS nanoprobe for H(2)O(2). The presence of antioxidant will prevent the growth of GNPs on the surface of the silica arrays from forming the structure which has strongest SERS-activity and the corresponding change in SERS intensity correlated well with the H(2)O(2) scavenging activity of the antioxidants. The H(2)O(2) scavenging activities of four plant-based antioxidants, tannic acid, citric acid, ferulic acid, and tartaric acid were studied. Our results showed the H(2)O(2) scavenging activities (SA(HP) values) of these four compounds were: tannic acid > ferulic acid > citric acid > tartaric acid.
一种基于表面增强拉曼散射（SERS）的新方法被开发出来，用于通过使用自组装的三维（3D）有序金纳米粒子（GNPs）前体复合（SiO 2 / GNPs）阵列作为纳米探针来估计抗氧化剂的抗氧化活性。H 2 O 2 可以将 AuCl 4 -还原为 Au（0），后者沉积在 SiO 2 / GNPs 阵列的表面上并扩大了 GNPs。随着 H 2 O 2 浓度的增加，沉积在硅核表面上的金的表面覆盖率相应增加，直到形成连续的金纳米壳（GNS）。SERS 光谱强度的变化与 H 2 O 2 浓度密切相关，这表明这种 SiO 2 / GNPs 阵列是一种潜在的用于 H 2 O 2 的 SERS 纳米探针。抗氧化剂的存在会阻止抗氧化剂在硅阵列表面上生长形成具有最强 SERS 活性的结构，并且相应的 SERS 强度变化与抗氧化剂的 H 2 O 2 清除活性密切相关。研究了四种基于植物的抗氧化剂，单宁酸、柠檬酸、阿魏酸和酒石酸的 H 2 O 2 清除活性（SA（HP）值）。我们的结果表明，这四种化合物的 H 2 O 2 清除活性（SA（HP）值）为：单宁酸>阿魏酸>柠檬酸>酒石酸。
