Zhang Jian, Matveeva Evgenia, Gryczynski Ignacy, Leonenko Zoya, Lakowicz Joseph R
Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, Maryland 21201, USA.
J Phys Chem B. 2005 Apr 28;109(16):7969-75. doi: 10.1021/jp0456842.
We studied a fluoroimmunoassay using metal-enhanced fluorescence (MEF) detection on silver film generated by vapor deposition method. The morphology of the silver film was controlled through the thickness of the film. A silica layer was coated on the silver film to protect the film and separate the fluorophore from the metal surface. Rabbit immunoglobulin G (IgG) was adsorbed on the silica by physiosorption and then dye-labeled anti-rabbit IgG was bound to the immobilized rabbit IgG. It was observed that the fluorophore was quenched on a thin silver film (2 nm), enhanced on a thick film (>5 nm), and reached saturation (ca. 10 times enhancement) at 20 nm. The MEF was also dependent on the thickness of the silica with a maximum at 10 nm. The lowest lifetime was observed on the 20 nm silver film, which was consistent with the saturation of MEF. These results showed the properties of a silver film needed for a maximum increase of fluorescence intensity in a fluoroimmunoassay. Dependence of the MEF on the emission wavelength was also studied using different dye-labeled anti-rabbit IgGs.
我们研究了一种采用金属增强荧光（MEF）检测的荧光免疫测定法，该检测基于通过气相沉积法生成的银膜。银膜的形态通过膜的厚度来控制。在银膜上涂覆一层二氧化硅层以保护该膜，并使荧光团与金属表面分离。兔免疫球蛋白G（IgG）通过物理吸附作用吸附在二氧化硅上，然后将染料标记的抗兔IgG与固定化的兔IgG结合。观察到荧光团在薄银膜（2纳米）上发生淬灭，在厚膜（>5纳米）上增强，并在20纳米时达到饱和（增强约10倍）。MEF也取决于二氧化硅的厚度，在10纳米时达到最大值。在20纳米银膜上观察到最低的寿命，这与MEF的饱和情况一致。这些结果表明了在荧光免疫测定中实现荧光强度最大增加所需的银膜特性。还使用不同的染料标记抗兔IgG研究了MEF对发射波长的依赖性。
