State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, PR China.
Biosens Bioelectron. 2011 May 15;26(9):3788-93. doi: 10.1016/j.bios.2011.02.033. Epub 2011 Feb 24.
A novel colorimetric immunosensing strategy based on protein-modified gold nanoparticle probes combined with atom transfer radical polymerization (ATRP) technology was proposed. Gold nanoparticles (GNPs, ∼15 nm) were functionalized with antibodies through an acylamide-bond between the carboxylic group of 11-mercaptoundecanoic acid that previously self-assembled on the surface of GNPs and the amino group of the protein (here, goat anti-rabbit immunoglobulim G (anti-IgG) used as model). The surface functionalized GNPs were used for IgG capture, which introduced initiator coupled anti-IgG (Ab2*) onto the surface of GNPs through immunoreactions. Subsequently triggered polymer growth resulted in the surface graft of preformed polymer chains onto nanoparticles that altered the optical property of GNPs. A distinct color change occurred. This could be designed for IgG detection. The spectrum absorption and colorimetric detection gave a linear range of 0.5-25 ng mL(-1) with a detection limit of 0.03 ng mL(-1) for IgG. The proposed approach showed high sensitivity from both visual and absorbance measurements. In spite of the limitations of available IgG antibodies, this approach could be easily extended to the detection of other biomarkers.
基于蛋白质修饰的金纳米粒子探针与原子转移自由基聚合（ATRP）技术相结合，提出了一种新颖的比色免疫传感策略。金纳米粒子（GNPs，约 15nm）通过 11-巯基十一酸上的羧酸基团与蛋白质上的氨基（此处，用作模型的兔抗山羊免疫球蛋白 G（抗-IgG））之间的酰胺键功能化。表面功能化的 GNPs 用于 IgG 捕获，通过免疫反应将偶联有引发剂的抗-IgG（Ab2*）引入到 GNPs 表面。随后引发的聚合反应导致预先形成的聚合物链在纳米颗粒表面接枝，改变了 GNPs 的光学性质。发生了明显的颜色变化。这可以用于 IgG 的检测。光谱吸收和比色检测给出了 IgG 的线性范围为 0.5-25ngmL-1，检测限为 0.03ngmL-1。该方法从视觉和吸光度测量都表现出很高的灵敏度。尽管现有的 IgG 抗体存在局限性，但这种方法可以很容易地扩展到其他生物标志物的检测。
