Beeram Srinivas R, Zamborini Francis P
Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, USA.
J Am Chem Soc. 2009 Aug 26;131(33):11689-91. doi: 10.1021/ja904387j.
Here we demonstrate control over the location of anti-immunoglobulin G (anti-IgG) proteins bound to Au nanoplates formed on glass and silicon samples. Preferential attachment to edge and vertex sites occurs by performing a thiol place-exchange reaction between mercaptoethanol (ME) attached to the Au nanostructures and mercaptoundecanoic acid (MUA) in solution, which localizes the carboxylic acid groups of MUA on the edge sites for subsequent amide linkage to anti-IgG. In contrast, anti-IgG attaches randomly onto the terrace regions of Au nanostructures functionalized directly in pure MUA or 1:10 MUA/ME solutions. Importantly, Au nanostructures with anti-IgG selectively bound to the edge sites exhibit significantly larger changes in the absorbance and wavelength of maximum absorbance (lambda(max)) of their localized surface plasmon resonance (LSPR) response upon binding than those with anti-IgG randomly attached to terrace regions. This leads to at least 500 times more sensitive detection of IgG down to 0.1 ng/mL.
在这里，我们展示了对结合在玻璃和硅样品上形成的金纳米板上的抗免疫球蛋白G（抗IgG）蛋白位置的控制。通过在附着于金纳米结构的巯基乙醇（ME）与溶液中的巯基十一烷酸（MUA）之间进行硫醇置换反应，实现了对边缘和顶点位置的优先附着，该反应将MUA的羧酸基团定位在边缘位置，以便随后与抗IgG形成酰胺键。相比之下，抗IgG随机附着在直接在纯MUA或1:10 MUA/ME溶液中功能化的金纳米结构的平台区域上。重要的是，抗IgG选择性地结合到边缘位置的金纳米结构在结合时其局部表面等离子体共振（LSPR）响应的吸光度和最大吸收波长（λ(max)）的变化比抗IgG随机附着在平台区域的金纳米结构显著更大。这导致对低至0.1 ng/mL的IgG检测灵敏度提高至少500倍。
