What is the best approach for estimating standard electrochemical potentials, E(0), from voltammograms that exhibit chemical irreversibility? The lifetimes of oxidized or reduced forms majority known redox species are considerably shorter than voltammetry acquisition times, resulting in irreversibility and making answer to this question outmost importance. Half-wave E(1/2), provide experimentally obtainable representation E(0). Due irreversible oxidation reduction, however, lack cathodic...

Abstract This article presents an investigation on the effectiveness of magnesium and its alloys as a novel class antibacterial biodegradable materials for ureteral stent applications. Magnesium is lightweight metallic material with beneficial properties use in medical devices. Ureteral one such example device that widely used to treat canal blockages clinically. The bacterial colony formation coupled encrustation surface from extended often leads clinical complications contributes failure...

The estimation of the driving force for photoinduced charge-transfer processes, using Rehm−Weller equation, requires employment redox and spectroscopic quantities describing participating electron donor acceptor. Although data are usually obtained from diluted solutions, potentials most frequently electrochemical measurements conducted in concentrated electrolyte solutions. To correct differences media, which various types conducted, a term, based on Born equation solvation energy ions, is...

Herein we report the first example of nanocrystal (NC) sensitized triplet–triplet annihilation based photon upconversion from visible to ultraviolet (vis-to-UV).

Introducing moderate charge-transfer character into nitro-aromatics is a key to producing strong fluorescence.

Abstract Large aza‐analogues of curved polycyclic aromatic hydrocarbons with a double‐helicene structure present unique features for molecular photonics. We the preparation and characterization three such structures. The synthesis these heterocyclic nanographenes involves only few high‐yield steps that use readily available starting materials. X‐ray analysis revealed each new dyes has conformational isomers: one diastereoisomer in meso form two enantiomers twisted forms [( P , )] M )]. low...

Photoinduced intramolecular direct arylation allows structurally unique compounds containing phenanthro[9',10':4,5]imidazo[1,2-f]phenanthridine and imidazo[1,2-f]phenanthridine skeletons, which mediate excited-state proton transfer (ESIPT), to be efficiently synthesized. The developed polycyclic aromatics demonstrate that the combination of five-membered ring structures with a rigid arrangement between donor acceptor provides means for attaining large fluorescence quantum yields, exceeding...

Abstract Molecular dipoles present important, but underutilized, methods for guiding electron transfer (ET) processes. While generate fields of Gigavolts per meter in their vicinity, reported differences between rates ET along versus against are often small or undetectable. Herein we show unprecedentedly large dipole effects on ET. Depending orientation, either ensure picosecond ET, turn completely off. Furthermore, favorable orientation makes possible even lipophilic medium, which appears...

Charge transfer and charge transport are by far among the most important processes for sustaining life on Earth making our modern ways of living possible. Involving multiple electron-transfer steps, photosynthesis cellular respiration have been principally responsible managing energy flow in biosphere planet since Great Oxygen Event. It is impossible to imagine organisms without mediated ion channels, or electron proton redox enzymes. Concurrently, electrons holes drive functionalities...

Abstract Electron-deficient π-conjugated functional dyes lie at the heart of organic optoelectronics. Adding nitro groups to aromatic compounds usually quenches their fluorescence via inter-system crossing (ISC) or internal conversion (IC). While strong electronic coupling with ensures benefits from these electron-withdrawing substituents, it also leads quenching. Here, we demonstrate how such affects photophysics acceptor–donor–acceptor fluorescent dyes, nitrophenyl acceptors and a...

Ever-growing global energy consumption, along with climate threats involving anthropogenic activities, places a premium on sustainable and environmentally safe sources. Solar radiation reaching the Earth's surface delivers at rate that considerably surpasses current projected rates of consumption. Through millennia evolution, photosynthesis evolved to harvest solar utilize it for anabolism caloric substances are stored used as biological fuels. Therefore, photosynthetic systems excellent...

Indocyanine green (ICG) remains as the only near infrared dye approved by FDA. Despite its long history of usage in clinical medicine, a systematic study effects serum proteins at physiologically relevant levels and temperature on absorption fluorescence characteristics ICG has been missing. We incubated concentrations range 0.6-25.8 μM McCoy's 5a cell culture medium, without with supplemental fetal bovine (FBS) 5% 10% levels. Our analyses spectra indicate that peak absorbance associated...

Abstract Interest in graphene as a two‐dimensional quantum‐well material for energy applications and nanoelectronics has increased exponentially the last few years. The recent advances large‐area single‐sheet fabrication of pristine have opened unexplored avenues expanding from nano‐ to meso‐scale applications. relatively low level absorptivity short lifetimes excitons suggest that it needs be coupled with light sensitizers order explore its feasibility photonic applications, such...

Suppressing the charge recombination (CR) that follows an efficient separation (CS) is of key importance for energy, electronics, and photonics applications. We focus on role dynamic gating impeding CR in a molecular rotor, comprising electron donor acceptor directly linked via single bond. The media viscosity has unusual dual effect dynamics CS this dyad. For solvents with intermediate viscosity, 1.5-3 times slower than CS. Lowering below ∼0.6 mPa s or increasing it above ∼10 makes 10-30...

Constructs derived from mammalian cells are emerging as a new generation of nano-scale platforms for clinical imaging applications.Herein, we report successful engineering hybrid nano-structures composed erythrocyte-derived membranes doped with FDA-approved near infrared (NIR) chromophore, indocyanine green (ICG), and surfacefunctionalized antibodies to achieve molecular targeting.We demonstrate that these constructs can be used targeted cancer in vitro.These optical nano-probes may provide...

Using cyclic voltammetry, we examined the dependence of reduction potentials six quinones on concentration supporting electrolyte. An increase in electrolyte concentration, resulting an solution polarity, caused positive shifts potentials. We ascribed observed changes to solvation energy and their anions media polarity. Analysis potentials, using Born equation, yielded unfeasibly small values for effective radii quinone species, that is, experimentally obtained were up 4-fold smaller than...

Photoinduced processes, leading to charge-transfer states with extended lifetimes, are of key importance for solar-energy-conversion applications. Utilizing external heavy-atom effect allowed us photogenerate long-lived transients electron donor−acceptor dyads. For an acceptor and a principal chromophore the dyads, we selected N-methylacridinium, donors thiophene, bithiophene, terthiophene were selected. While photoinduced charge transfer, mediated by investigated occurred in picosecond time...

Controlling charge transfer at a molecular scale is critical for efficient light harvesting, energy conversion, and nanoelectronics. Dipole-polarization electrets, the electrostatic analogue of magnets, provide means “steering” electron transduction via local electric fields generated by their permanent dipoles. Here, we describe first demonstration utility anthranilamides, moieties with ordered dipoles, controlling intramolecular transfer. Donor–acceptor dyads, each containing single...

Ovarian cancer remains the deadliest malignancy of female reproductive system. The ability to identify and destroy all ovarian tumor nodules may have a termendous impact on preventing recurrence, patient survival. objective this study is investigate effectiveness nano-structured system for combined near infrared (NIR) fluorescence imaging human epidermal growth factor receptor-2 (HER2) over-expression, as biomarker cells, photothermal destruction these cells in vitro.The consists dye,...

This article describes the development and examination of surface coatings that suppress adhesion between glass surfaces polymer microspheres. Superparamagnetic doping allowed for exerting magnetic forces on microbeads. The carboxyl functionalization provided means coating beads with polyethylene glycol (PEG) different molecular weight. Under gravitational force, microbeads settled similar coatings. We examined efficacy removing from by applying a pulling force ~1.2 pN. percent remaining...

A facile nonlithographic method for expedient fabrication of microfluidic devices poly(dimethylsiloxane) is described. Positive-relief masters the molds are directly printed on smooth substrates. For formation connecting channels and chambers inside polymer components devices, cavity-forming elements adhered to surfaces masters. Using this approach, we fabricated detection bacterial spores basis enhancement emission terbium (III) ions.

The photophysical properties of a series 9-arylacridinium conjugates in solid glass matrices composed sucrose octaacetate have been determined. fluorescence the charge-shift states is significantly enhanced because retardation nonradiative pathways for back-electron transfer. Changes more than 3 orders magnitude back-electron-transfer rates (sucrose vs conventional solvents at room temperature) were observed. Transient spectra displayed long-lived species microsecond time regime thianthrene...