Molecular engineering of organic semiconductors enables noble metal-comparable SERS enhancement and sensitivity

Gokhan Demirel*, Rebecca L. M. Gieseking, Resul Ozdemir, Simon Kahmann, Maria A. Loi, George C. Schatz, Antonio Facchetti, Hakan Usta

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

12 Citations (Scopus)
115 Downloads (Pure)

Abstract

Nanostructured molecular semiconductor films are promising Surface-Enhanced Raman Spectroscopy (SERS) platforms for both fundamental and technological research. Here, we report that a nanostructured film of the small molecule DFP-4T, consisting of a fully pi-conjugated diperfluorophenyl-substituted quaterthiophene structure, demonstrates a very large Raman enhancement factor (>10(5)) and a low limit of detection (10(-9) M) for the methylene blue probe molecule. This data is comparable to those reported for the best inorganic semiconductor- and even intrinsic plasmonic metal-based SERS platforms. Photoluminescence spectroscopy and computational analysis suggest that both charge-transfer energy and effective molecular interactions, leading to a small but non-zero oscillator strength in the charge-transfer state between the organic semiconductor film and the analyte molecule, are required to achieve large SERS enhancement factors and high molecular sensitivities in these systems. Our results provide not only a considerable experimental advancement in organic SERS figure-of-merits but also a guidance for the molecular design of more sensitive SERS systems.

Original languageEnglish
Article number5502
Number of pages9
JournalNature Communications
Volume10
DOIs
Publication statusPublished - 3-Dec-2019

Keywords

  • FIELD-EFFECT TRANSISTORS
  • PLASMON RESONANCES
  • RAMAN-SCATTERING
  • SPECTROSCOPY
  • PARAMETERS
  • POLYTHIOPHENE
  • NANOPARTICLES
  • GRAPHENE
  • ELECTRON
  • FILMS

Cite this