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Nano Research

Article Title

Bimetallic nano-mushrooms with DNA-mediated interior nanogaps for high-efficiency SERS signal amplification

Authors

Jianlei Shen, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Jing Su, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Juan Yan, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Bin Zhao, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Dongfang Wang, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Siyi Wang, Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key, Laboratory for Carbon-based Functional Materials & Devices, Soochow University, Suzhou 215123, China
Kun Li, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Mengmeng Liu, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Yao He, Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key, Laboratory for Carbon-based Functional Materials & Devices, Soochow University, Suzhou 215123, China
Sanjay Mathur, Institute of Inorganic Chemistry, University of Cologne, D-50939 Cologne, Germany
Chunhai Fan, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
Shiping Song, Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China Institute of Inorganic Chemistry, University of Cologne, D-50939 Cologne, Germany

Keywords

surface-enhanced Raman scattering, biometallic nanostructure, nano-mushroom, nanogap, gold nanoparticle

Abstract

Uniform silver-containing metal nanostructures with well-defined nanogaps hold great promise for ultrasensitive surface-enhanced Raman scattering (SERS) analyses. Nevertheless, the direct synthesis of such nanostructures with strong and stable SERS signals remains extremely challenging. Here, we report a DNA- mediated approach for the direct synthesis of gold–silver nano-mushrooms with interior nanogaps. The SERS intensities of these nano-mushrooms were critically dependent on the area of the nanogap between the gold head and the silver cap. We found that the formation of nanogaps was finely tunable by controlling the surface density of 6-carboxy-X-rhodamine (ROX) labeled single-stranded DNA (ssDNA) on the gold nanoparticles. We obtained nano-mushrooms in high yield with a high SERS signal enhancement factor of ~1.0 × 109, much higher than that for Au–Ag nanostructures without nanogaps. Measurements for single nano- mushrooms show that these structures have both sensitive and reproducible SERS signals.

Graphical Abstract

Publisher

Tsinghua University Press

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