Ag nano-assemblies on Si surface via CTAB-assisted galvanic reaction for sensitive and reliable surface-enhanced Raman scattering detection

SENSORS AND ACTUATORS B-CHEMICAL

卷:304

Article

Lu, Han^1,2  Jin, Mingliang^1,2,3  Ma, Qilin⁴  Yan, Zhibin^1,2  Liu, Zhenping^1,2  Wang, Xin^1,2,3  Akinoglu, Eser Metin³  van den Berg, Albert^1,2,5,6  Zhou, Guofu^1,2,3  Shui, Lingling^1,2,4 

[1] South China Normal Univ, Natl Ctr Int Res Green Optoelect, Guangzhou 510006, Guangdong, Peoples R China

[2] South China Normal Univ, South China Acad Adv Optoelect, Guangzhou 510006, Guangdong, Peoples R China

[3] South China Normal Univ, Int Acad Optoelect Zhaoqing, Zhaoqing 526238, Peoples R China

[4] South China Normal Univ, Sch Informat & Optoelect Sci & Engn, Guangzhou 510006, Guangdong, Peoples R China

[5] Univ Twente, BIOS Lab On A Chip Grp, Tech Med Ctr, MESA Inst Nanotechnol, NL-7522 NB Enschede, Netherlands

[6] Univ Twente, Max Planck Ctr Complex Fluid Dynam, NL-7522 NB Enschede, Netherlands

关键词: Surface-enhanced Raman scattering;    Nanoparticle;    Nano-assembly;    Galvanic reaction;    Single-molecule detection;    Molecular diagnostics;   

DOI  :  10.1016/j.snb.2019.127224

来源: Elsevier

【 摘 要 】

In this work, we report a quick and controllable method for fabricating Ag nanoparticles (NPs) and nano-assemblies (NAs) on silicon (Si) surface via a galvanic reaction assisted by surfactant hexadecyltrimethylammonium bromide (CTAB). Obtained Si substrates with high density Ag NAs serve as surface-enhanced Raman scattering (SERS) substrates for unlabelled molecular sensing. The addition of CTAB enables not only the electromagnetic enhancement by controllable producing Ag NAs hotspots, but also the signal enhancement by enriching probe molecules via hydrophobic interaction. Two concentration regimes of 1.0 x10(-8)-1.0 x 10(-1)1 M and 1.0 x 10(-12)-1.0 x 10(-16) M have been obtained for quantitative and qualitative detection of Rhodamine 6G (R6G) in aqueous solution, respectively. As a result, for determination of R6G, the quantitative and qualitative detection limits of 1.0 x 10(-11) and 1.0 x 10(-16) M have been obtained, respectively, with high reproducibility showing the relative standard deviation (RSD) of similar to 7.3%. Simulation has been carried out using finite-difference time-domain (FDTD) to evaluate the dependence of electric field on the size and inter-gap of Ag NPs, showing good agreement with experimental results. The high sensitivity also enables SERS characterization of non-resonant and low Raman cross-section biomolecules, for example, amino acids. Such a fabrication process is simple, fast, cheap and reproducible; and therefore, it would be helpful to produce high sensitive SERS substrates to broaden their applications in chemical and biological fields for molecular diagnostics to single-/multiple-molecule detection.

【 授权许可】

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