Department of Chemistry, College of Arts and Sciences, University of Cincinnati, 301 West Clifton Court, Cincinnati, OH 45221-0172, USA.
Sensors (Basel). 2017 Feb 15;17(2):378. doi: 10.3390/s17020378.
Integration of noble metal nanoparticles with proteins offers promising potential to create a wide variety of biosensors that possess both improved selectivity and versatility. The multitude of functionalities that proteins offer coupled with the unique optical properties of noble metal nanoparticles can allow for the realization of simple, colorimetric sensors for a significantly larger range of targets. Herein, we integrate the structural protein collagen with 10 nm gold nanoparticles to develop a protein-nanoparticle conjugate which possess the functionality of the protein with the desired colorimetric properties of the nanoparticles. Applying the many interactions that collagen undergoes in the extracellular matrix, we are able to selectively detect both glucose and heparin with the same collagen-nanoparticle conjugate. Glucose is directly detected through the cross-linking of the collagen fibrils, which brings the attached nanoparticles into closer proximity, leading to a red-shift in the LSPR frequency. Conversely, heparin is detected through a competition assay in which heparin-gold nanoparticles are added to solution and compete with heparin in the solution for the binding sites on the collagen fibrils. The collagen-nanoparticle conjugates are shown to detect both glucose and heparin in the physiological range. Lastly, glucose is selectively detected in 50% mouse serum with the collagen-nanoparticle devices possessing a linear range of 3-25 mM, which is also within the physiologically relevant range.
将贵金属纳米粒子与蛋白质结合，为创建具有改善的选择性和多功能性的各种生物传感器提供了有前途的潜力。蛋白质提供的多种功能以及贵金属纳米粒子的独特光学特性，可以实现简单的比色传感器，用于检测更大范围的目标。在这里，我们将结构蛋白胶原蛋白与 10nm 金纳米粒子结合，开发出一种具有蛋白质功能和所需纳米粒子比色特性的蛋白质-纳米粒子缀合物。利用胶原蛋白在细胞外基质中经历的许多相互作用，我们能够使用相同的胶原蛋白-纳米粒子缀合物选择性地检测葡萄糖和肝素。葡萄糖通过胶原蛋白纤维的交联直接检测，这使得附着的纳米粒子更接近，导致 LSPR 频率的红移。相反，肝素通过竞争测定检测，其中将肝素-金纳米粒子添加到溶液中，并与溶液中的肝素竞争胶原蛋白纤维上的结合位点。结果表明，胶原蛋白-纳米粒子缀合物可以在生理范围内检测葡萄糖和肝素。最后，使用具有 3-25mM 线性范围的胶原蛋白-纳米粒子器件选择性地检测 50%小鼠血清中的葡萄糖，该范围也在生理相关范围内。
