School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia, United States.
Langmuir. 2011 Mar 15;27(6):3198-205. doi: 10.1021/la104787w. Epub 2011 Feb 4.
We have demonstrated a nanoengineered substrate composed of micropatterned silver nanoparticles to be used for the label-free mapping of adsorbed biomolecules. We utilized surface-enhanced Raman scattering (SERS) phenomenon to monitor the known bioanalytes, protein A and human immunoglobulin G (IgG). The SERS substrate was composed of a poly(alylamine hydrochloride) (PAH)/poly(styrenesulfonate) (PSS) layer-by-layer (LbL) nanocoating micropatterned with silver nanoparticles confined to microscopic stripes. Selective adsorption of biomacromolecules is facilitated by the amine-terminated LbL nanocoating, which prevents the surface adsorption of positively charged protein A across the surface except on the patterned regions containing negatively charged silver nanoparticles. Furthermore, adsorption of IgG on predetermined regions is facilitated by the selective binding of the Fc region of IgG to protein A. This label-free SERS approach provides accurate, selective, and fast detection of protein A and IgG solutions with a nanomolar concentration, down to below 1 nM for IgG in solution. This method could also be utilized for the facile detection of proteins in field conditions as well as in clinical, forensic, industrial, and environmental laboratories.
我们已经证明，由微图案化银纳米粒子组成的纳米工程化基底可用于吸附生物分子的无标记测绘。我们利用表面增强拉曼散射（SERS）现象来监测已知的生物分析物，即蛋白质 A 和人免疫球蛋白 G（IgG）。SERS 基底由聚（烯丙基胺盐酸盐）（PAH）/聚（苯乙烯磺酸盐）（PSS）层层（LbL）纳米涂层组成，该涂层具有银纳米粒子的微图案化，这些纳米粒子被限制在微观条纹中。通过胺端接的 LbL 纳米涂层促进了生物大分子的选择性吸附，该纳米涂层可以防止带正电荷的蛋白质 A 在整个表面上吸附，除非在含有带负电荷的银纳米粒子的图案化区域上。此外，由于 IgG 的 Fc 区域与蛋白质 A 的选择性结合，因此有利于 IgG 在预定区域上的吸附。这种无标记的 SERS 方法可用于对蛋白质 A 和 IgG 溶液进行准确、选择性和快速的检测，其纳米摩尔浓度可低至 1 nM 以下，溶液中的 IgG 浓度可低至 1 nM 以下。该方法还可用于现场条件以及临床、法医、工业和环境实验室中蛋白质的简便检测。
