Nowak-Lovato K L, Rector K D
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Appl Spectrosc. 2009 Apr;63(4):387-95. doi: 10.1366/000370209787944406.
In this paper the ability to develop a gold-core, silver-shell surface-enhanced Raman scattering (SERS) nanosensor that has both a targeting component as well as a sensing component is demonstrated. The nanosensor is capable of targeting through the FcepsilonRI receptor-mediated endocytic pathway due to the adsorption of 2,4-epsilon-dinitrophenol-L-lysine (DNP) ligand on the nanoparticle surface. The nanosensor is also sensitive to pH changes in the endocytic vesicle within the pH range of 4.5-7.5 by 4-mercaptopyridine (4-MPy) adsorbed to the particle surface. The targeting and sensing moieties do not significantly interfere with each other's function. The sensing component of the nanosensor is calibrated with in vivo measurements of rat basophil leukemia (RBL-2H3) cells in standard buffer solutions using the ionophore nigericin, which serves to equilibrate the external [H(+)] concentration with that of the cell compartments. The targeting of the nanosensor is verified with a beta-hexosaminidase assay. It is also demonstrated that the targeted nanosensor is capable of making accurate cellular pH measurements in RBL-2H3 cells, out to ninety minutes after targeted nanosensor addition. Whole-cell, time-lapse, hyperspectral image cubes demonstrating endocytic vesicular pH changes during FcepsilonRI receptor mediated endocytosis are demonstrated.
本文展示了开发一种具有靶向成分和传感成分的金核-银壳表面增强拉曼散射（SERS）纳米传感器的能力。由于2,4-ε-二硝基苯酚-L-赖氨酸（DNP）配体吸附在纳米颗粒表面，该纳米传感器能够通过FcepsilonRI受体介导的内吞途径进行靶向。通过吸附在颗粒表面的4-巯基吡啶（4-MPy），该纳米传感器对4.5-7.5 pH范围内的内吞小泡中的pH变化也很敏感。靶向和传感部分不会显著干扰彼此的功能。使用离子载体尼日利亚菌素在标准缓冲溶液中对大鼠嗜碱性粒细胞白血病（RBL-2H3）细胞进行体内测量，对纳米传感器的传感成分进行校准，尼日利亚菌素用于使外部[H(+)]浓度与细胞区室的浓度平衡。通过β-己糖胺酶测定法验证纳米传感器的靶向性。还证明了靶向纳米传感器能够在添加靶向纳米传感器后长达90分钟内对RBL-2H3细胞进行准确的细胞pH测量。展示了全细胞、延时、高光谱图像立方体，其显示了FcepsilonRI受体介导的内吞过程中内吞小泡的pH变化。
