Gold-silver core-shell nanodumbbells in solution state as a highly sensitive and reproducible assay platform for bacterial genome detection

Hyeon Ho Shin, Hye Jin Lee, Min Ji Hwang, Jungwoo Kim, Hyunwoo Kim, Sang Hwan Nam, Jeong Su Park, Ji Eun Hwang, Eu Suk Kim, Young Suk Park, Yung Doug Suh, Dong Kwon Lim

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Surface-enhanced Raman scattering (SERS) has been investigated as a promising spectroscopic tool for various assay platforms. However, key challenges, such as the reproducibility and sensitivity of this tool should be addressed to enable it to become a reliable and practical method for future clinical applications. Although the single-molecule sensitivity of SERS has already been proven in dry state analysis, its signal reproducibility remains a key challenge in developing a real assay platform. The signal reproducibility of SERS can be significantly improved by obtaining the Raman signal from the solution state; however, the sensitivity of this method is not satisfactory. In this study, we demonstrate a method to overcome both key challenges by using a solution-state formation of gold-silver core-shell nanodumbbells (GSNDs) with target nucleic acid and nanoscale Ag shell formation, which was proven to exhibit single-molecule sensitivity in dry state analysis. To utilize the concept of a reliable assay platform in solution, diverse parameters such as the length of the target sequences, hybridization conditions, number density of probe sequences, and the Ag shell thickness are investigated. The hybridization yield of Au dimer reaches up to 79.36% for E. faecalis, indicating that the hybridization yields are target sequence dependent. It is strongly correlated with detection limit for the target bacteria. The solution-state GSND-based assay shows a highly sensitive results for bacterial target DNA with no mutual interference and excellent reproducibility. The method can identify extremely low concentrations of bacteria (4.5 cfu mL−1), which is much superior to the conventional PCR (4500 cfu mL−1) and culture-based assays (45 cfu mL−1). The results envision the current GSND-based assay as a promising assay platform for future clinical applications.

Original languageEnglish
Article number130784
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 2021 Dec 15

Bibliographical note

Funding Information:
This work was supported by the Industrial Strategic Technology Development Program ( 10077582 ) funded by the Ministry of Trade, Industry, and Energy (MOTIE), Republic of Korea. D.-K. Lim also acknowledge support from the National Research Foundation of Korea ( NRF-2017M3D1A1039421 ). Y.D. Suh also acknowledge support from the Global Research Laboratory (GRL) Program of NRF funded by the Ministry of Science and ICT ( 2016911815 ) and KRICT funds ( KK2161-22 ).

Publisher Copyright:
© 2021 Elsevier B.V.


  • Bacterial genome DNA
  • Gold-silver core-shell nanodumbbells
  • Raman spectroscopy
  • Sepsis
  • Surface-enhanced Raman scattering

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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