Department of Electrical, Division of Materials Science and Engineering, Computer Engineering and Photonic Center, Mechanical Engineering, Boston University, Boston, MA 02215, USA.
Proc Natl Acad Sci U S A. 2010 Jul 6;107(27):12086-90. doi: 10.1073/pnas.1002849107. Epub 2010 Jun 21.
Light scattering phenomena in periodic systems have been investigated for decades in optics and photonics. Their classical description relies on Bragg scattering, which gives rise to constructive interference at specific wavelengths along well defined propagation directions, depending on illumination conditions, structural periodicity, and the refractive index of the surrounding medium. In this paper, by engineering multifrequency colorimetric responses in deterministic aperiodic arrays of nanoparticles, we demonstrate significantly enhanced sensitivity to the presence of a single protein monolayer. These structures, which can be readily fabricated by conventional Electron Beam Lithography, sustain highly complex structural resonances that enable a unique optical sensing approach beyond the traditional Bragg scattering with periodic structures. By combining conventional dark-field scattering micro-spectroscopy and simple image correlation analysis, we experimentally demonstrate that deterministic aperiodic surfaces with engineered structural color are capable of detecting, in the visible spectral range, protein layers with thickness of a few tens of Angstroms.
周期性系统中的光散射现象在光学和光子学领域已经研究了几十年。它们的经典描述依赖于布拉格散射，这导致在特定波长处产生建设性干涉，具体取决于照明条件、结构周期性和周围介质的折射率。在本文中，通过在确定的非周期性纳米粒子阵列中设计多频比色响应，我们证明了对单层蛋白质存在的显著增强的灵敏度。这些结构可以通过传统的电子束光刻技术来制造，它们支持高度复杂的结构共振，从而实现了一种独特的光学传感方法，超越了传统的周期性结构的布拉格散射。通过结合传统的暗场散射微光谱学和简单的图像相关分析，我们通过实验证明，具有设计结构颜色的确定的非周期性表面能够在可见光范围内检测到厚度为几十埃的蛋白质层。
