TY - JOUR
T1 - Molecular engineering of organic semiconductors enables noble metal-comparable SERS enhancement and sensitivity
AU - Demirel, Gokhan
AU - Gieseking, Rebecca L.M.
AU - Ozdemir, Resul
AU - Kahmann, Simon
AU - Loi, Maria A.
AU - Schatz, George C.
AU - Facchetti, Antonio
AU - Usta, Hakan
N1 - Funding Information:
This work was supported by Gazi University (Grant No: 05/2015-19), TUBITAK (Grant No: 117F468), and Flexterra Corporation. S.K. thanks the Deutsche For-schungsgemeinschaft for a research fellowship (Grant No: 408012143). R.L.M.G. and G.C.S. were also supported by NSF Grant CHE-1760537.
Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - 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 π-conjugated diperfluorophenyl-substituted quaterthiophene structure, demonstrates a very large Raman enhancement factor (>105) 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.
AB - 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 π-conjugated diperfluorophenyl-substituted quaterthiophene structure, demonstrates a very large Raman enhancement factor (>105) 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.
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U2 - 10.1038/s41467-019-13505-7
DO - 10.1038/s41467-019-13505-7
M3 - Article
C2 - 31796731
AN - SCOPUS:85076056462
VL - 10
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 5502
ER -