UC Berkeley/UCSF Graduate Program in Bioengineering and Department of Bioengineering, Biomolecular Nanotechnology Center, Berkeley Sensor and Actuator Center, University of California, Berkeley, California 94720, USA.
ACS Nano. 2011 Jul 26;5(7):5383-9. doi: 10.1021/nn2002807. Epub 2011 Jun 13.
The disassembly of a core-satellite nanostructured substrate is presented as a colorimetric biosensor observable under dark-field illumination. The fabrication method described herein utilizes thiol-mediated adsorption and streptavidin-biotin binding to self-assemble core-satellite nanostructures with a sacrificial linking peptide. Biosensing functionality is demonstrated with the protease trypsin, and the optical properties of the nanoassemblies are characterized. A figure of merit is presented to determine the optimal core and satellite size for visual detection. Nanoassemblies with 50 nm cores and 30 or 50 nm satellites are superior as these structures achieve an orange to green color shift greater than 70 nm that is easily discernible by the naked eye. This colorimetric substrate may prove to be a favorable alternative to liquid-based colloidal sensors and a useful visual readout mechanism for point-of-care microfluidic diagnostic assays.
提出了一种将核-卫星纳米结构基底进行拆卸的方法，将其作为在暗场照明下可观察到的比色生物传感器。本文所描述的制造方法利用巯基介导的吸附和链霉亲和素-生物素结合，自组装具有牺牲连接肽的核-卫星纳米结构。通过蛋白酶胰蛋白酶演示了生物传感功能，并对纳米组装体的光学性质进行了表征。提出了一个质量因数来确定用于目视检测的最佳核和卫星尺寸。50nm 核和 30nm 或 50nm 卫星的纳米组装体更优越，因为这些结构实现了大于 70nm 的橙色到绿色的颜色位移，肉眼很容易识别。这种比色底物可能是液体基于胶体传感器的有利替代品，并且是用于即时护理微流控诊断分析的有用目视读出机制。
