Nanobiophysics, MESA(+) Institute for Nanotechnology & MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
J Colloid Interface Sci. 2011 Apr 1;356(1):123-30. doi: 10.1016/j.jcis.2010.12.082. Epub 2011 Jan 3.
The infiltration of enhanced green fluorescent protein (EGFP) into nanochannels of different diameters in mesoporous silica particles was studied in detail by fluorescence microspectroscopy at room temperature. Silica particles from the MCM-41, ASNCs and SBA-15 families possessing nanometer-sized (3-8 nm in diameter) channels, comparable to the dimensions of the infiltrated guest protein EGFP (barrel structure with dimensions of 2.4 nm × 4.2 nm), were used as hosts. We found that it is necessary to first functionalize the surfaces of the silica particles with an amino-silane for effective encapsulation of EGFP. We demonstrated successful infiltration of the protein into the nanochannels based on fluorescence microspectroscopy and loading capacity calculations, even for nanochannel diameters approaching the protein dimensions. We studied the spatial distributions of the EGFPs within the silica particles by confocal laser scanning microscopy (CLSM) and multimode microscopy. Upon infiltration, the fluorescence lifetime drops as expected for an emitter embedded in a high refractive index medium. Further, the spectral properties of EGFP are preserved, confirming the structural integrity of the infiltrated protein. This inorganic-protein host-guest system is an example of a nanobiophotonic hybrid system that may lead to composite materials with novel optical properties.
室温下通过荧光显微光谱详细研究了增强型绿色荧光蛋白（EGFP）在不同直径的介孔硅纳米通道中的渗透。使用具有纳米尺寸（直径为 3-8nm）通道的 MCM-41、ASNCs 和 SBA-15 家族的硅粒子作为宿主，这些通道的尺寸与渗透的客体蛋白 EGFP（桶状结构，尺寸为 2.4nm×4.2nm）相当。我们发现，首先用氨基硅烷对硅粒子表面进行功能化对于 EGFP 的有效封装是必要的。我们通过荧光显微光谱和负载能力计算证明了蛋白质成功渗透到纳米通道中，即使纳米通道直径接近蛋白质尺寸。我们通过共聚焦激光扫描显微镜（CLSM）和多模显微镜研究了 EGFP 在硅粒子内的空间分布。渗透后，荧光寿命如预期的那样下降，因为发射体嵌入在高折射率介质中。此外，EGFP 的光谱特性得以保留，证实了渗透蛋白质的结构完整性。这种无机-蛋白质主客体系统是纳米生物光子混合系统的一个例子，可能会导致具有新型光学性质的复合材料。
