Superhydrophobic 3D-Assembled Metallic Nanoparticles for Trace Chemical Enrichment in SERS Sensing

Youhai Liu, Nan Zhang, Dylan Tua, Yingkun Zhu, Jacob Rada, Wenhong Yang, Haomin Song, Alexis C. Thompson, R. Lorraine Collins, Qiaoqiang Gan*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


The performance of surface-enhanced Raman spectroscopy (SERS) is determined by the interaction between highly diluted analytes and boosted localized electromagnetic fields in nanovolumes. Although superhydrophobic surfaces are developed for analyte enrichment, i.e., to concentrate and transfer analytes toward a specific position, it is still challenging to realize reproducible, uniform, and sensitive superhydrophobic SERS substrates over large scales, representing a major barrier for practical sensing applications. To overcome this challenge, a superhydrophobic SERS chip that combines 3D-assembled gold nanoparticles on nanoporous substrates is proposed, for a strong localized field, with superhydrophobic surface treatment for analyte enrichment. Intriguingly, by concentrating droplets in the volume of 40 µL, the sensitivity of 1 nm is demonstrated using 1,2-bis(4-pyridyl)-ethylene molecules. In addition, this unique chip demonstrates a relative standard deviation (RSD) of 2.2% in chip-to-chip reproducibility for detection of fentanyl at 1 µg mL–1 concentration, revealing its potential for quantitative sensing of chemicals and drugs. Furthermore, the trace analysis of fentanyl and fentanyl-heroin mixture in human saliva is realized after a simple pretreatment process. This superhydrophobic chip paves the way toward on-site and real-time drug sensing to tackle many societal issues like drug abuse and the opioid crisis.

Original languageEnglish (US)
Article number2204234
Issue number51
StatePublished - Dec 22 2022

Bibliographical note

Funding Information:
This work was supported by the National Science Foundation (ECCS‐1807463).

Publisher Copyright:
© 2022 Wiley-VCH GmbH.


  • analyte enrichment
  • anodic aluminum oxide (AAO)
  • self-assembly
  • superhydrophobic
  • surface-enhanced Raman spectroscopy (SERS)

ASJC Scopus subject areas

  • Biotechnology
  • Chemistry(all)
  • Biomaterials
  • Materials Science(all)
  • Engineering (miscellaneous)


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