Identification of Metalloporphyrins with High Sensitivity Using Graphene-Enhanced Resonance Raman Scattering

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• 作者：Bo-Hyun Kim ; Daechul Kim ; Sungho Song ; DongHyuk Park ; Il-Suk Kang ; Dae Hong Jeong ; Seokwoo Jeon
• 刊名：Langmuir
• 出版年：2014
• 出版时间：March 18, 2014
• 年：2014
• 卷：30
• 期：10
• 页码：2960-2967
• 全文大小：482K
• 年卷期：v.30,no.10(March 18, 2014)
• ISSN：1520-5827

文摘

Graphene-enhanced resonance Raman scattering (GERRS) was performed for the detection of three different metallo-octaethylporphyrins (M-OEPs; M = 2H, FeCl, and Pt) homogeneously thermal vapor deposited on a graphene surface. GERRS of M-OEPs were measured using three different excitation wavelengths, 位_ex = 405, 532, and 633 nm, and characterized detail vibrational bands for the identification of M-OEPs. The GERRS spectra of Pt-OEP at 位_ex = 532 nm showed 29 and 162 times signal enhancement ratio on graphene and on graphene with Ag nanoclusters, respectively, compared to the spectra from bare SiO₂ substrate. This enhancement ratio, however, was varied with M-OEPs and excitation wavelengths. The characteristic peaks and band shapes of GERRS for each M-OEP were measured with high sensitivity (100 pmol of thermal vapor deposited Pt-OEP), and these facilitate the selectively recognition of molecules. Also, the peaks shift and broadening provide the evidence of the interaction between graphene and M-OEPs through the charge transfer and 蟺-orbital interaction. The increase of graphene layer induced the decrease of signal intensity and GERRS effect was almost not observed on the thick graphite flakes. Further experiments with various substrates demonstrated that the interaction of single layer of graphene with molecule is the origin of the Raman signal enhancement of M-OEPs. In this experiment, we proved the graphene is a good alternative substrate of Raman spectroscopy for the selective detection of various metalloporphyrins with high sensitivity.