title: Plasmon-enhanced fluorescence imaging with silicon-based silver chips for protein and nucleic acid assay.
abstract: Metal-enhanced fluorescence shows great potential for improving the sensitivity of fluoroscopy, which has been widely used in protein and nucleic acid detection for biosensor and bioassay applications. In comparison with the traditional glass-supported metal nanoparticles (MNPs), the introduction of a silicon substrate has been shown to provide an increased surface-enhanced Raman scattering (SERS) effect due to the coupling between the MNPs and the semiconducting silicon substrate. In this work, we further study the fluorescence-enhanced effect of the silicon-supported silver-island (Ag@Si) plasmonic chips. In particular, we investigate their practical application of improving the traditional immunoassay such as the biotin-streptavidin-based protein assay and the protein-/nucleic acid-labeled cell and tissue samples. The protein assay shows a wavelength-dependent enhancement effect of the Ag@Si chip, with an enhancement factor ranging from 1.2 (at 532 nm) to 57.3 (at 800 nm). Moreover, for the protein- and nucleic acid-labeled cell and tissue samples, the Ag@Si chip provides a fluorescence enhancement factor of 3.0-4.1 (at 800 nm) and a significant improvement in the signal/background ratio for the microscopy images. Such a ready accommodation of the fluorescence-enhanced effect for the immunoassay samples with simple manipulations indicates broad potential for applications of the Ag@Si chip not only in biological studies but also in the clinical field.
authors.affiliation: College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, PR China; Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, PR China. Electronic address: yuanbing@suda.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Yuan
authors.affiliation: Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, PR China.
authors.forename: Xiangxu
authors.initials: X
authors.lastname: Jiang
authors.affiliation: College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, PR China; Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, PR China.
authors.forename: Chu
authors.initials: C
authors.lastname: Yao
authors.affiliation: College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, PR China; Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, PR China.
authors.forename: Meimei
authors.initials: M
authors.lastname: Bao
authors.affiliation: College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, PR China; Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, PR China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Electronic and Information Engineering, Soochow University, Suzhou 215006, PR China.
authors.forename: Yujiang
authors.initials: Y
authors.lastname: Dou
authors.affiliation: School of Engineering, University of Guelph, Guelph N1G 2W1, Canada.
authors.forename: Yinze
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, PR China. Electronic address: yaohe@suda.edu.cn.
authors.forename: Yao
authors.initials: Y
authors.lastname: He
authors.affiliation: College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, PR China; Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, PR China. Electronic address: yangkai@suda.edu.cn.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.affiliation: College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, PR China; Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, PR China; National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, PR China.
authors.forename: Yuqiang
authors.initials: Y
authors.lastname: Ma
mesh_terms: D045744:Cell Line, Tumor; D006801:Humans; D007118:Immunoassay; D053768:Metal Nanoparticles; D009696:Nucleic Acids / Q000032:analysis*; D011506:Proteins / Q000032:analysis*; D012825:Silicon; D012834:Silver; D013059:Spectrum Analysis, Raman
chemical_list: D009696:Nucleic Acids; D011506:Proteins; D012834:Silver; D012825:Silicon
keywords: Nucleic acid assay; Protein assay; Signal/background ratio; Silicon-supported silver-chip; Surface-plasmon enhanced fluorescence