Modulation of Excited-State Proton Transfer Dynamics in a Model Lactim–Lactam Tautomeric System by Anisotropic Gold Nanoparticles

Abstract

The past few decades have witnessed significant advances in the development of functionalized gold nanoparticles (GNPs) for diverse applications in various fields such as chemistry, biology, pharmacy, and physics. However, a recent in vivo toxicity study of GNPs in Drosophila melanogaster demonstrated that GNPs are capable of inducing mutagenesis. Considering mutagenicity and tautomerism (lactim–lactam and amine–imine) of DNA base pairs are correlated with each other, a recent theoretical study reveal the modification of double-proton-transfer process of guanine–cytosine DNA base pairs upon interaction with the gold surface (Au(111)). However, there is a dearth of experimental data about the proton-transfer (PT) process in isolated base pairs on gold nanosurface. In this particular work, we have chosen a model lactim–lactam tautomeric system, namely, 1-(2-hydroxy-5-chloro-phenyl)-3,5-dioxo-1H-imidazo-[3,4-b] isoindole (ADCL), and carried out for the first time a comprehensive study of the modification of excited-state PT dynamics in the presence of synthesized isotropic (spherical) and anisotropic (trianglular, rod, and trigonal bipyramidal) GNPs by means of steady-state and time-resolved fluorescence spectroscopy. The PT process operative in ADCL was experimentally found to be accelerated on the anisotropic gold nanosurface, whereas spherical-shaped GNPs showed little impact on the dynamics of the above-mentioned photophysical phenomenon. Therefore, our experimental results regarding the modification of lactim–lactam tautomerism of a model compound on the gold nanosurface are an indirect evidence of mutation caused by GNPs.

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

“…In contrast, the non-cytotoxic nature of 13 nm citrate-capped gold nanoparticles has been reported [ 66 ]. Another recent study on Drosophila melanogaster showed mutagenicity of isotropic and anisotropic gold nanoparticles through the process of proton transfer (PT) [ 67 ]. A 1-(2-hydroxy-5-chlorophenyl)-3,5-dioxo-1 H -imidazo[3,4- b ]isoindole (ADCL)-based PT process on anisotropic gold nanoparticles was found to be accelerated compared to isotropic gold nanoparticles.…”

Denaturant-Mediated Modulation of the Formation and Drug Encapsulation Responses of Gold Nanoparticles

“…The recent progress in the flourishing field of chemical science observes a bright and enriched contribution of nanomaterials chemistry, which primarily circulated upon different interesting and important material systems structured at the nanometer scale. − These nanomaterial systems actually exhibit a wide and diverse range of applications, from biomedical and pharmaceutical research area ,,− to constructing different energy-related devices, , involving in various optoelectronic and catalytic applications ,, and also in the broad applications of chemistry and biology . Among a large number of nanomaterial systems, the most common list includes nanoparticles (NPs), ,, nanoclusters, different metal oxide nanostructures, , graphene oxide, quantum dots, carbon dots, metal perovskites, and so on. Now, in this growing list of different nanomaterial systems with their diverse applications, in the present study, we mainly focus on the well-accepted isotropic (spherical) gold nanoparticle system.…”

Theoretical insights into excited-state hydrogen bonding effects and intramolecular proton transfer (ESIPT) mechanism for BTS system

“…9-18 . By the light of nature, both applied and cognitive attention have been paid to ESIPT phenomenon, which becomes a demanding subject of research [19][20][21][22][23][24][25] .Generally, ESIPT means the transfer of a hydroxyl (or amino) proton to an oxygen (or nitrogen) acceptor via pre-existing hydrogen bonds. Upon photoexcitation, an unstable position of proton is resulted from the projection of the nuclear wave function of molecule on the excited-state potential energy surface (PES) [26][27][28][29][30][31][32][33][34][35] .…”

“…9-18 . By the light of nature, both applied and cognitive attention have been paid to ESIPT phenomenon, which becomes a demanding subject of research [19][20][21][22][23][24][25] .…”