Chemical Environment Effects on the Photophysical Behavior of Two-Photon Materials

2003 ◽  
Vol 771 ◽  
Author(s):  
Jeremy C. Collette ◽  
Aaron W. Harper

AbstractA set of six new two-photon engineered diethylamino-substituted styryl pyrazine (DEASP) dyes have been developed as chemically responsive chromophores. This work employs UV/Vis spectroscopy to draw structure-optical property relationships and to quantify the solvatochromic effect observed for these dyes. Absorbance profiles for each of these dyes have been measured in 22 solvents ranging from very nonpolar (TMS) to very polar (water). Absorbance maxima of the longest wavelength π→π transitions have been correlated to nine empirical scales of solvent polarity, and a comparative analysis is presented. Dimroth & Reichardt's and Kamlet & Taft's single parameter scales have been recalculated with spectral data obtained for the six DEASP dyes. The correlation of these established and recalculated scales are shown and discussed. DEASP chromophores are found to exhibit high sensitivity to their chemical environment and exceptional range as solvatochromic probes. Current models of solvatochromism, based on dipolar probes, cannot account for the solvatochromism observed in our quadrupolar dyes, and fail to describe the effect of the chemical environment on this family of twophoton dyes. The need to develop a more universal model of solvation incorporating higher order moment contributions is apparent.

2015 ◽  
Vol 6 (4) ◽  
pp. 2419-2426 ◽  
Author(s):  
Karolina A. Korzycka ◽  
Philip M. Bennett ◽  
Eduardo Jose Cueto-Diaz ◽  
Geoffrey Wicks ◽  
Mikhail Drobizhev ◽  
...  

We present a modular approach to photo-labile protecting groups based on photoinduced electron transfer, providing high sensitivity to two-photon excitation.


Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1055
Author(s):  
Muni Raj Maurya ◽  
Haseena Onthath ◽  
Hagar Morsy ◽  
Najam-US-Sahar Riyaz ◽  
Muna Ibrahim ◽  
...  

Monitoring exhaled breath is a safe, noninvasive method for determining the health status of the human body. Most of the components in our exhaled breath can act as health biomarkers, and they help in providing information about various diseases. Nitric oxide (NO) is one such important biomarker in exhaled breath that indicates oxidative stress in our body. This work presents a simple and noninvasive quantitative analysis approach for detecting NO from exhaled breath. The sensing is based on the colorimetric assisted detection of NO by m-Cresol Purple, Bromophenol Blue, and Alizaringelb dye. The sensing performance of the dye was analyzed by ultraviolet–visible (UV–Vis) spectroscopy. The study covers various sampling conditions like the pH effect, temperature effect, concentration effect, and selective nature of the dye. The m-Cresol Purple dye exhibited a high sensitivity towards NO with a detection limit of ~0.082 ppm in the linear range of 0.002–0.5 ppm. Moreover, the dye apprehended a high degree of selectivity towards other biocompounds present in the breath, and no possible interfering cross-reaction from these species was observed. The dye offered a high sensitivity, selectivity, fast response, and stability, which benchmark its potential for NO sensing. Further, m-Cresol Purple dye is suitable for NO sensing from the exhaled breath and can assist in quantifying oxidative stress levels in the body for the possible detection of COVID-19.


2021 ◽  
Vol 21 (5) ◽  
pp. 3059-3064
Author(s):  
A. K. M. Kafi ◽  
Aizam Bin Kasri ◽  
Rajan Jose

The fabrication of a network of glucose oxidase-horseradish peroxidase/tin oxide (GOx-HRP/SnO2), immobilized onto a glassy carbon electrode (GCE) and its utilization as a biosensor for glucose detection is reported. The network established with GOx-HRP/SnO2 possess high sensitivity and stability by performing the electrocatalytic features in the sensing of glucose. The turbidity of fabrication had been scanned and analyzed using UV-vis spectroscopy. The morphology and composition of the fabricated GOx-HRP/SnO2 networks were characterized by scanning electron microscopy (SEM). Cyclic voltammetry and amperometry were employed to study the electrochemical properties of the proposed biosensor. The effect of applied electrode potential and pH were systemically investigated. The biosensor responds to glucose at work potential values between −400 mV, and exhibited a lower detection limit (0.025 mM) and long linear range (0.25 to 7.0 mM), and was resistant to common interferences.


2019 ◽  
Vol 15 ◽  
pp. 2438-2446 ◽  
Author(s):  
Alessandro Iagatti ◽  
Baihao Shao ◽  
Alberto Credi ◽  
Barbara Ventura ◽  
Ivan Aprahamian ◽  
...  

In this work we apply a combination of steady state and time resolved luminescence and absorption spectroscopies to investigate the excited-state dynamics of a recently developed molecular photoswitch, belonging to the hydrazone family. The outstanding properties of this molecule, involving fluorescence toggling, bistability, high isomerization quantum yield and non-negligible two-photon absorption cross section, make it very promising for numerous applications. Here we show that the light induced Z/E isomerization occurs on a fast <1 ps timescale in both toluene and acetonitrile, while the excited state lifetime of the Z-form depends on solvent polarity, suggesting a partial charge transfer nature of its low lying excited state. Time-resolved luminescence measurements evidence the presence of a main emission component in the 500–520 nm spectral range, attributed to the Z-isomer, and a very short living blue-shifted emission, attributed to the E-isomer. Finally, transient absorption measurements performed upon far-red excitation are employed as an alternative method to determine the two-photon absorption cross-section of the molecule.


2020 ◽  
Vol 59 (20) ◽  
pp. 14920-14931
Author(s):  
Xu-Dan Bi ◽  
Rong Yang ◽  
Yue-Chen Zhou ◽  
Daomei Chen ◽  
Guo-Kui Li ◽  
...  

2005 ◽  
Vol 871 ◽  
Author(s):  
Han Young Woo ◽  
Dmitry Korystov ◽  
Alexander Mikhailovsky ◽  
Guillermo C. Bazan

AbstractA series of tetradonor substituted [2.2]paracyclophane-based two-photon absorption (TPA) fluorophores were designed, synthesized and characterized. Different substituents were chosen to modulate the conjugation and the donor strength and to allow the molecules to be neutral (N series, organic-soluble) or charged (C series, water-soluble). The overall set of compounds series allows us to examine the correlation among the solvent polarity, donor ability of the substituents, and TPA action cross section (ηδd, where δ is the TPA cross section and η is the quantum yield). In water, a significant drop of both δ and η is observed, approximately one-third relative to those in toluene. Weaker donors and/or weaker acceptors with enhanced conjugation are a better choice due to a minimized quenching related to strong charge transfer (CT) upon excitation. One thus needs to fine-tune the magnitude of CT and find an optimal balance among CT,δ and η.


2003 ◽  
Vol 158 (2-3) ◽  
pp. 163-170 ◽  
Author(s):  
Stephen M Kuebler ◽  
Kevin L Braun ◽  
Wenhui Zhou ◽  
J.Kevin Cammack ◽  
Tianyue Yu ◽  
...  

2013 ◽  
Vol 6 (1) ◽  
pp. 1-9 ◽  
Author(s):  
P. R. Deepti ◽  
J. Shanti

Triglycine sulphate (TGS), an important ferroelectric material has been widely used in the fabrication of high sensitivity infrared detectors at room temperature. Single crystals of KDP doped TGS was grown by slow evaporation method at room temperature in this study. The grown crystal was characterized by UV-Vis spectroscopy, FTIR spectroscopy, powder X-ray diffraction studies, and ferroelectric studies. KDP doped TGS crystals were found to be highly transparent and full faced. The experimental results evidence the suitability of the grown crystal for optoelectronic applications.  Keywords: Crystal growth; KDP-doped TGS; Ferroelectric studies  © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  doi: http://dx.doi.org/10.3329/jsr.v6i1.16584 J. Sci. Res. 6 (1), 1-9 (2014)


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