SERS investigation of neocuproine adsorption on silver: Influence of electrode potential on methyl groups

Abstract

Study of molecules adsorption on charged surfaces is important for biologically relevant substances where the potential at the interface such as living cell membrane is a significant parameter in the processes of their transportation or transmembrane penetration. In this work, a hybrid optical/electrochemical surface‐enhanced Raman scattering (SERS) technique was applied to get new insight into the adsorption state and conformational equilibrium of neocuproine, which serves as a nucleic acid biosensor in clinical diagnostics and has biological activity towards several types of carcinoma. The density functional theory calculations performed for several rotational conformations and their anion radicals were used to determine the geometrical and energetic characteristics, to evaluate the rotational barrier, to obtain the vibrational assignment, and to consider the metal‐adsorbate charge transfer. The dependence of SERS spectra on surface potential is ascribed to a change of the rotational dynamics of methyl groups from hindered to almost free at potentials ≤−200 mV. It is demonstrated for the first time that SERS spectroscopy is capable to recognize the surface species, which differ in the methyl group internal rotation.

A universal solution processed interfacial bilayer enabling ohmic contact in organic and hybrid optoelectronic devices

“…S7, ESI †) whilst being significantly faster to model. 52 To explore the role of BCP-Ag interactions (equivalently, NCP-Ag interactions), we simulated the adsorption of NCP on an Ag (111) surface containing adatoms. The high adsorption energies in this system (E b = 2.15 eV and 2.82 eV for pristine and adatom-containing surfaces respectively, Fig.…”

Impact of Surface Adsorption on Metal–Ligand Binding of Phenanthrolines

“…The formation of ferroin results in greater changes in the spectra compared to complexation with copper, although a small shoulder emerges on the peak at 713 cm –1 for the copper complex. Despite a higher noise level in the baseline, the characteristic peaks at 1302, 1396, and 1493 cm –1 are all present in the neocuproine spectrum (Figure b) . These peaks are also present in the copper complex with neocuproine, albeit with a slight red-shift.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

“…Solovyeva et al used SERS to investigate the influence of electrode on the adsorption of neocuproine on silver. They state that the study of molecular adsorption on charged surfaces is important for biologically relevant substances where the potential at the interface such as living cell membrane is a significant parameter in the processes of their transportation or transmembrane penetration . Sun and co‐workers described a SERS‐based method for the detection of thermal neutrons that used 4‐mercaptophenylboronic acid, a natural boron‐containing and high intrinsic Raman‐active compound.…”

“…They state that the study of molecular adsorption on charged surfaces is important for biologically relevant substances where the potential at the interface such as living cell membrane is a significant parameter in the processes of their transportation or transmembrane penetration. [49] Sun and co-workers described a SERS-based method for the detection of thermal neutrons that used 4-mercaptophenylboronic acid, a natural boron-containing and high intrinsic Raman-active compound. The SERS method for thermal neutron detection would provide a simple new way for neutron utilization, administration, and radiation protection.…”