Abstract
Using p-aminothiophenol (PATP) molecules on a gold substrate and high-vacuum tip-enhanced Raman spectroscopy (HV-TERS), we show that the vibrational spectra of these molecules are distinctly different from those in typical surface-enhanced Raman spectroscopy. Detailed first-principles calculations help to assign the Raman peaks in the TERS measurements as Raman-active and IR-active vibrational modes of dimercaptoazobenzene (DMAB), providing strong spectroscopic evidence for the dimerization of PATP molecules to DMAB under the TERS setup. The activation of the IR-active modes is due to enhanced electromagnetic field gradient effects within the gap region of the highly asymmetric tip-surface geometry. Fermi resonances are also observed in HV-TERS. These findings help to broaden the versatility of TERS as a promising technique for ultrasensitive molecular spectroscopy.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
