Influence of excitation wavelength, solution pH, incubation time, absolute configuration (S and R) and constitutional isomerism (ortho-, meta- and para-) on the adsorption on the surface of Ag nanoparticles of N-benzylamino(boronphenyl)methylphosphonic acid analogues

Abstract

Five analogs of N-benzylamino(boronophenyl)methylphosphonic acid, which is a potential inhibitor of kinase and protease enzymes whose activation has been detected during tumor growth, proliferation, and invasion were synthetized. These compounds were adsorbed on the surface of Ag nanoparticles (AgNPs) with a diameter of ~ 15 nm from an aqueous solution under various environmental conditions, including excitation wavelengths (488.0, 632.8, and 785.0 nm), pH values of the solutions (from pH = 5 to pH = 11), absolute configuration (S and R), and constitutional isomerism (ortho–, meta–, and para–). Using surface-enhanced Raman scattering (SERS) technique, specific conclusions were drawn about the dynamic nature of these compounds at the solid/liquid interface, which is biologically important as the boronic acid motif acts as a transition state analog that forms hydrogen and covalent bonds in the active site of the enzyme.