Zhu Shaoli, Fu Yongqi
Photonics Centre, School of Electronic and Electrical Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Biomed Microdevices. 2009 Jun;11(3):579-83. doi: 10.1007/s10544-008-9267-3.
The hybrid Au-Ag triangular nanoparticles were proposed for the purpose of biosensing. To construct the nanoparticles, an Au thin film was deposited on top of the Ag nanoparticles supported with glass substrate. The hybrid nanoparticles can prevent oxidation of the pure Ag nanoparticles due to the Au protective layer caped on the Ag nanoparticles. The hybrid nanoparticles were designed using finite-difference and time-domain algorithm. Extinction spectra of the hybrid nanoparticles excited by visible light beam with plane wave were calculated, and the corresponding electric fields at peak position of the extinction spectra were expressed also. It is clear that the hybrid nanoparticles can excite the localized surface plasmon resonance wave which can be used to detect biomolecules. As an application example, we presented relevant detection results by means of using protein A to covalently link surface of the hybrid nanoparticles. Refractive index sensitivity of the hybrid nanoparticles was derived through both computational numerical calculation and experimental detection. Both the calculated and the experimental extinction spectra show that the hybrid Au-Ag nanoparticles are useful for detecting the biomolecules.
提出了用于生物传感目的的金-银混合三角形纳米颗粒。为了制备这些纳米颗粒，在玻璃基底支撑的银纳米颗粒顶部沉积了一层金薄膜。由于金保护层覆盖在银纳米颗粒上，混合纳米颗粒可以防止纯银纳米颗粒氧化。使用有限差分和时域算法设计了混合纳米颗粒。计算了由平面波可见光激发的混合纳米颗粒的消光光谱，并给出了消光光谱峰值位置处的相应电场。很明显，混合纳米颗粒可以激发可用于检测生物分子的局域表面等离子体共振波。作为一个应用实例，我们展示了通过使用蛋白A共价连接混合纳米颗粒表面的相关检测结果。通过计算数值计算和实验检测得出了混合纳米颗粒的折射率灵敏度。计算和实验消光光谱均表明，金-银混合纳米颗粒可用于检测生物分子。
