Interactions between DNA Purines and Ruthenium Ammine Complexes within Nanostructured Sol−Gel Silica Matrixes

Abstract

The interactions between DNA purines (guanine and adenine) and three ruthenium ammine complexes (hexaammineruthenium(III) chloride, hexaammineruthenium(II) chloride, and ruthenium-red) were studied in a confined environment, within sol-gel silica matrixes. Two encapsulation methods were rehearsed (differing in temperature and condensation pH), in order to analyze the effects of the sol-gel processes on the purines and on the Ru complexes separately. The extent of decomposition of the Ru complexes, as well as the interactions established with the purine bases, proved to be determined by the coencapsulation method. Combined results by diffuse reflectance UV-vis and infrared spectroscopies showed that, when coencapsulation is carried out at 60 degrees C, specific H bonding interactions are established between the amine group of Ade and the ammine groups of the Ru complex or the hydroxo group of an early decomposition product. These are responsible for the important role of the purine in inhibiting the oxidation reactions of the Ru(II) and Ru(III) complexes. In contrast, Gua establishes preferential H bonds with the matrix (mainly due to the carbonyl group), leading to higher yields in the final oxidation products of the Ru complexes, namely, trimers and dimers. Direct covalent bonding of either purine to the metal was not observed.

Photoelectrochemical Aptasensors Constructed with Photosensitive PbS Quantum Dots/TiO2 Nanoparticles for Detection of Kanamycin

“…The Kana aptamer/PEI/PbS QDs/TiO 2 NPs/ITO electrode was then rinsed thoroughly with ultra-pure water. Finally, the Kana aptamer/PEI/PbS QDs/TiO 2 NPs/ITO electrode was immersed in 0.2 mmol L –1 Ru­(NH 3 ) 6 3+ for 60 min to interact with the purine of aptamer …”

Graphene Oxide Based Recyclable in Vivo Device for Amperometric Monitoring of Interferon-γ in Inflammatory Mice

“…One absorption peak centered at 280 nm was observed in the UV–vis absorption spectra of both Ru­(NH 3 ) 6 3+ and aptamer­(Ru). The band is assigned to charge transfer from NH 3 to Ru 3+ in the Ru­(NH 3 ) 6 3+ complex . A peak centered at 260 nm was observed in the UV–vis spectra of aptamers, attributed to the characteristic DNA peak .…”

“…The band is assigned to charge transfer from NH 3 to Ru 3+ in the Ru(NH 3 ) 6 3+ complex. 37 A peak centered at 260 nm was observed in the UV−vis spectra of aptamers, attributed to the characteristic DNA peak. 38 The ratio between readings at 260 and 280 nm (A 260 /A 280 ) represented the purity of DNA.…”

Reactivity of the Antitumor Complex (H2trz)[trans-RuCl4(N2-Htrz)2] in the Presence of DNA Purines within a Fluorinated Silica Matrix

“…The infrared spectra of crystalline guanine and adenine and their UV spectra in aqueous solution have been analyzed in detail elsewhere. , The study of their interactions with coencapsulated trans -Htrz was preceded by a characterization of their behavior within this new fluorinated silica matrix.…”

“…The best way to study the interactions of this complex with DNA bases, namely the purines, is to favor the encounter between the two molecules within a confined environment. For ruthenium nitrosylnitrate and ruthenium ammine complexes, nanostructured, hydrophilic, and relatively dense silica matrices, synthesized by a two-step sol gel process, using HCl as hydrolysis catalyst, proved to be suitable for this purpose. , …”