Polarization effect in tip-enhanced infrared nanospectroscopy studies of the selective Y5 receptor antagonist Lu AA33810
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A novel approach of combining conventional infrared spectroscopy (IR) and atomic force microscopy (AFM) is presented to better understand the behavior of a drug adsorbed on a metal substrate at the nanoscale level. Tip-enhanced infrared nanospectroscopy (TEIRA) was used for the first time to investigate Lu AA33810, a selective brain-penetrating Y5 receptor antagonist, after immobilization on gold nanoparticles (GNPs). Here, a gold coated AFM tip and gold substrate were used to obtain the near-field electromagnetic field trapping effect. Because of the huge signal enhancement, it was possible to obtain the spectral information regarding the self-assembled monolayer of the investigated molecule. The effect of two orthogonal polarizations (p- and s-polarization modulations) of the excitation laser beam on the spectral patterns is also discussed. The results show that there is a strong relationship between the state of polarization of the incident radiation and the relative infrared band intensities. Another factor affecting the observed spectral differences is the topology of the metal substrate, which may result in the induction of a cross-polarization effect. The performed analysis indicates that the C–C bond from the cyclohexyl group is oriented almost parallel to the metal surface. Conversely, the p- and s-polarized spectral variations suggest that the O=S=O angle is high enough to enable the simultaneous interaction of both oxygen atoms with the GNPs.
Keywordstip-enhanced infrared nanospectroscopy polarization modulation Y5 receptor antagonist gold nanoparticles adsorption
The research was performed by the use of the equipment purchased in the frame of the project co-funded by the Małopolska Regional Operational Program Measure 5.1 Krakow Metropolitan Area as an important hub of the European Research Area for 2007–2013 (No. MRPO.05.01.00–12–013/15). This work was also supported by the National Science Centre Poland (No. 2016/21/D/ ST4/02178 to N. P. and 2017/01/X/ST4/00428 to E. P.). The authors gratefully acknowledge M. Oćwieja, Ph. D, J. Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, for GNPs synthesis.
- Qian, H. M.; Xu, M.; Li, X. W.; Ji, M. W.; Cheng, L.; Shoaib, A.; Liu, J. J.; Jiang L.; Zhu, H. S.; Zhang, J. T. Surface micro/nanostructure evolution of Au–Ag alloy nanoplates: Synthesis, simulation, plasmonic photothermal and surface-enhanced Raman scattering applications. Nano Res. 2016, 9, 876–885.CrossRefGoogle Scholar
- Centrone, A.; Lahiri, B.; Holland, G. E. Chemical imaging beyond the diffraction limit using photothermal induced resonance microscopy. Microsc. Anal. 2013, 27, 6–9.Google Scholar
- Frey, B. L.; Corn, R. M.; Weibel, S. C. Polarization-modulation approaches to reflection-absorption spectroscopy. In Handbook of Vibrational Spectroscopy. Griffiths, P. R., Ed.; John Wiley & Sons: New York, 2001; pp 1042–1056.Google Scholar
- Walker, M. W.; Wolinsky, T. D.; Jubian, V.; Chandrasena, G.; Zhong, H. L.; Huang, X. Y.; Miller, S.; Hegde, L. G.; Marsteller, D. A.; Marzabadi, M. R. et al. The novel neuropeptide Y Y5 receptor antagonist Lu AA33810 [N-[[trans-4-[(4,5-Dihydrobenzothiepino[5,4-d]thiazol-2-yl)amino]cyclohexyl] methyl]-methanesulfonamide] exerts anxiolytic- and antidepressant-like effects in rat models of stress sensitivity. J. Pharmacol. Exp. Ther. 2009, 328, 900–911.CrossRefGoogle Scholar
- Packiarajan, M.; Marzabadi, M. R.; Desai, M.; Lu, Y. L.; Noble, S. A.; Wong, W. C.; Jubian, V.; Chandrasena, G.; Wolinsky, T. D.; Zhong, H. L. et al. Discovery of Lu AA33810: A highly selective and potent NPY5 antagonist with in vivo efficacy in a model of mood disorder. Bioorg. Med. Chem. Lett. 2011, 21, 5436–5441.CrossRefGoogle Scholar
- Pięta, E.; Piergies, N.; Oćwieja, M.; Domin, H.; Paluszkiewicz, C.; Bielańska, E.; Kwiatek, W. M. Monitoring the interfacial behavior of selective Y5 receptor antagonist on colloidal gold nanoparticle surfaces: Surface-enhanced vibrational spectroscopy studies. J. Phys. Chem. C 2017, 121, 17276–17288.CrossRefGoogle Scholar
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