Plasmonic Acceleration of a Photochemical Replicator

Abstract

The photoinduced decarbonylation of an a-diketone adduct generates 2,6-dimethoxyanthracene in the ground state. The photochemical product can also absorb the incoming photons and transfer its excitation energy to another molecule of the reactant to establish an autocatalytic loop. In the presence of silver nanoparticles, the efficiency of energy transfer increases significantly with a concomitant acceleration of the autocatalytic transformation. In principle, this mechanism to establish kinetic amplification can be ex-tended to any photoactivatable fluorophore, if reactant and product can be engineered to satisfy the spectral requirements necessary for energy transfer. Furthermore, the resulting photochemical replicators can be exploited to monitor the influence of metallic nanostructures on photochemical reactions with convenient fluorescence measurements. In turn, the associated plasmonic effects offer the opportunity to accelerate autocatalysis with nanoscale resolution.

Effects of Temperature and Concentration on the Rate of Photobleaching of Erythrosine in Water

“…It should be noted that the onset of self-catalysis means that the rate of bleaching takes on a significant time dependence. It should be emphasized that there are other examples of photochemical self-catalyzed reactions in the literature. − These reactions cover a variety of systems where light promotes unusual chemistry but nonetheless the range of photochemical self-catalyzed processes remains relatively small.…”

BODIPYs with Photoactivatable Fluorescence

“…[24] Early examples of photoactivatable fluorophores were based on the covalent attachment of photocleavable ortho-nitrobenzyl groups to fluorescein. [25][26][27] Similar structural designs were later adapted to photoactivate also the fluorescence of anthracene, [28][29][30][31][32][33][34][35][36] resorufin, [37] rhodamine, pyrene, [60] coumarin, [61][62][63][64][65][66] dihydrofurans, [67][68][69][70][71][72] acridinone, [73][74][75] and thiocarbonyl [76] derivatives. In most of these photoresponsive compounds, fluorescence switching is a result of a change in either the rate of nonradiative deactivation of the excited fluorophore or its molar absorption coefficient at the excitation wavelength (λ Ex ).…”

Live-Cell Imaging at the Nanoscale with Bioconjugatable and Photoactivatable Fluorophores

“…This fundamental phenomenon was termed photofluorescence almost five decades ago, but its potential biological implications were only recognized much later in seminal reports on photocaged fluoresceins. − These investigations demonstrated that the photoinduced disconnection of appropriate functional groups from organic chromophores can be exploited to convert a nonemissive reactant into an emissive product (panel a in Figure ). In the wake of these pioneering contributions, similar operating principles to photoactivate fluorescence were extended to a diversity of emissive chromophores, including anthracene, − resorufin, rhodamine, − pyrene, coumarin, − dihydrofurans, − acridinone, − borondipyrromethene − (BODIPY), and thiocarbonyl derivatives. In all instances, irradiation at λ Ac activates the photochemical conversion of reactant into product and illumination at λ Ex excites the latter species to produce fluorescence.…”