Insights into the binding interactions at the nano-bio interface: Electrode potential and wavelength dependence study

• Published in: Applied surface science Vol. 562; p. 150228
• Main Authors: Pięta, Ewa, Lopez-Ramirez, Maria Rosa, Paluszkiewicz, Czesława, Kwiatek, Wojciech M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2021
• Subjects: Charge-transfer; Density functional theory (DFT) calculations; Electrode potential dependence; Ethyl 5-[(2-furanylcarbonyl)amino]-3-methyl-4-thiocyanato-2-thiophenecarboxylate (CBR-5884); Excitation-wavelength dependence; Surface-enhanced Raman spectroscopy (SERS); Electrode potential dependence; Excitation-wavelength dependence; Charge-transfer; Density functional theory (DFT) calculations; Ethyl 5-[(2-furanylcarbonyl)amino]-3-methyl-4-thiocyanato-2-thiophenecarboxylate (CBR-5884); Surface-enhanced Raman spectroscopy (SERS)
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2021.150228

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•Understanding the physicochemical interactions at the nano-bio interface.•Binding interplay between the electrochemically roughened Ag electrode and CBR-5884.•Selective contribution of the charge-transfer mechanism in the SERS spectra.•Effect of potential and excitation wavelength on the molecule–metal interaction.
This article presents the first physical insights into the binding interaction between the electrochemically roughened silver electrode and CBR-5884, an anticancer drug. The work gives a comprehensive account of the influence of applied electrode potential and excitation wavelength on the molecular adsorption on the metal surface. This type of research, based on the unique surface phenomena, may lead to a far-reaching improvement in biosensing and bioimaging applications, which may result in significant improvement in combined cancer chemo-immunotherapy.
The main concern of the paper was to explore the possibility of surface-enhanced Raman spectroscopy (SERS) to understand physicochemical interactions at the nano-bio interface. Simultaneously, the molecular geometry in the equilibrium state and Raman frequencies were calculated based on the density functional theory (DFT) at the B3LYP 6-311G(d,p) level of theory.
The highest SERS signal amplification is observed at the potential of –0.3 V for lower excitation wavelength, while at more negative electrode potential the molecule slowly desorbs or decomposes from the metal surface. At higher wavelengths, the enhancement of the SERS of individual bands is observed, which confirms the selective contribution of the charge-transfer mechanism in the SERS spectra along with the detection of different metal complexes adsorbed on the surface.