Application of Photonic Crystal Enhanced Fluorescence to a Cytokine Immunoassay
Application of Photonic Crystal Enhanced Fluorescence to a Cytokine Immunoassay
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DOI：
10.1021/ac801377k
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发表时间：
2008-12-01
影响因子：
7.4
通讯作者：
Cunningham, Brian T.
中科院分区：
文献类型：
--
作者：
Mathias, Patrick C.;Ganesh, Nikhil;Cunningham, Brian T.
光子晶体表面被证明是一种提高检测灵敏度和分辨率的方法，用于使用荧光标签来量化液体测试样本中分析物蛋白质分子的浓度。光子晶体表面上的共振耦合电磁场的空间分布的计算机建模被用来估计增强因子的幅度相比，在普通玻璃表面上执行相同的荧光测定，和光子晶体结构的制造和测试，以实验验证的性能使用的蛋白质肿瘤坏死因子-α（TNF-α）的夹心免疫测定。所展示的光子晶体制造方法利用nanoreplica成型技术，该技术允许以与共聚焦微阵列激光扫描仪兼容的格式大面积廉价制造结构。光子晶体上的荧光点的信噪比相对于载玻片增加至少5倍，允许将1.6pg/mL的TNF-α浓度与光子晶体表面上的噪声区分开。此外，在光子晶体表面上的检测的最小定量极限是在载玻片上的极限的三分之一-从18下降到6 pg/m。免疫测定性能的提高允许以蛋白质微阵列形式更准确地定量TNF-α的生理相关浓度，所述蛋白质微阵列形式可以扩展到多种细胞因子。
Photonic crystal surfaces are demonstrated as a means for enhancing the detection sensitivity and resolution for assays that use a fluorescent tag to quantify the concentration of an analyte protein molecule in a liquid test sample. Computer modeling of the spatial distribution of resonantly coupled electromagnetic fields on the photonic crystal surface are used to estimate the magnitude of enhancement factor compared to performing the same fluorescent assay on a plain glass surface, and the photonic crystal structure is fabricated and tested to experimentally verify the performance using a sandwich immunoassay for the protein tumor necrosis factor-alpha (TNF-alpha). The demonstrated photonic crystal fabrication method utilizes a nanoreplica molding technique that allows for large-area inexpensive fabrication of the structure in a format that is compatible with confocal microarray laser scanners. The signal-to-noise ratio for fluorescent spots on the photonic crystal is increased by at least 5-fold relative to the glass slide, allowing a TNF-alpha concentration of 1.6 pg/mL to be distinguished from noise on a photonic crystal surface. In addition, the minimum quantitative limit of detection on the photonic crystal surface is one-third the limit on the glass slide-a decrease from 18 to 6 pg/m. The increased performance of the immunoassay allows for more accurate quantitation of physiologically relevant concentrations of TNF-alpha in a protein microarray format that can be expanded to multiple cytokines.