Photophysical properties and pH sensing applications of luminescent salicylaldehyde derivatives

2015 ◽  
Vol 42 (5) ◽  
pp. 5027-5048 ◽  
Author(s):  
Jiaoyan Liu ◽  
Jinghui Cheng ◽  
Xiaofeng Ma ◽  
Xiangge Zhou ◽  
Haifeng Xiang
Keyword(s):  
Photophysical Properties ◽  
Ph Sensing ◽  
Sensing Applications ◽  
Salicylaldehyde Derivatives

The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh
Keyword(s):  
Biological Imaging ◽  
Ph Sensing ◽  
Hydrophobic Residue ◽  
Ideal Candidate ◽  
Self Assembling ◽  
Sensing Applications ◽  
Β Sheets ◽  
The Stability ◽  
Dynamics Simulations

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>

scholarly journals Near-Infrared pH Sensor Based on a SPEEK–Polyaniline Polyelectrolyte Complex Membrane

Proceedings ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 11 ◽  
Author(s):  
Nedal Y. Abu-Thabit
Keyword(s):  
Polyelectrolyte Complex ◽  
Near Infrared ◽  
Response Times ◽  
Oxidative Polymerization ◽  
Ph Sensor ◽  
Ph Sensing ◽  
Ph Values ◽  
Sensing Applications ◽  
Ph Range ◽  
Speek Membrane

A polyelectrolyte complex (PEC) membrane based on sulfonated poly (ether ether ketone) and polyaniline (SPEEK-PANI) was developed for pH sensing applications. Aniline was polymerized in the presence of the SPEEK membrane by using in situ chemical oxidative polymerization to yield an ionically crosslinked SPEEK-PANI membrane. The fabricated membrane exhibited sensitivity in the physiological pH range of 2–8. The PEC membrane pH sensor showed good absorption properties in the near-infrared region (NIR). The membrane showed fast response during a de-doping process (≈90 s), while longer response times are essential for doping processes from the alkaline/neutral pH region to the acidic pH region, which is attributed to the presence of highly acidic sulfonic acid groups with a high buffering capacity in the PEC membrane. The SPEEK-PANI membrane exhibited slightly higher water uptake compared to the neat SPEEK membrane. The membrane exhibited good stability, as it was stored in 1M HCl solution for more than 2 years without physical or visual deterioration. A preconditioning step in 1M HCl ensured that the results were reproducible and allows the pH sensor to be used repeatedly. The PEC sensor membranes are suitable for applications that start at low pH values and move upwards to higher pH values in the 2–8 pH range.

ChemInform Abstract: Molecular Photoionic Switches with an Internal Reference Channel for Fluorescent pH Sensing Applications.

ChemInform ◽  
2010 ◽  
Vol 28 (4) ◽  
pp. no-no
Author(s):  
A. P. DE SILVA ◽  
H. Q. N. GUNARATNE ◽  
T. GUNNLAUGSSON ◽  
P. L. M. LYNCH
Keyword(s):  
Ph Sensing ◽  
Reference Channel ◽  
Internal Reference ◽  
Sensing Applications

scholarly journals Toward Prediction of Nonradiative Decay Pathways in Organic Compounds II: Two Internal Conversion Channels in BODIPYs

2019 ◽  
Author(s):  
Zhou Lin ◽  
Alexander Kohn ◽  
Troy Van Voorhis
Keyword(s):  
Quantum Yield ◽  
Rational Design ◽  
Internal Conversion ◽  
Photophysical Properties ◽  
Data Driven ◽  
Laser Dyes ◽  
Intermediate Structure ◽  
Sensing Applications ◽  
Aided Design ◽  
Semi Empirical

<div>Boron-dipyrromethene (BODIPY) molecules are widely used as laser dyes and have therefore become a popular research topic within recent decades. Numerous studies have been reported for the rational design of BODIPY derivatives based on their spectroscopic and photophysical properties, including absorption and fluorescence wavelengths (<i>λ</i><sub>abs</sub> and <i>λ</i><sub>fl</sub>), oscillator strength (<i>f</i>), nonradiative pathways, and quantum yield (<i>ϕ</i>). In the present work, we illustrate a theoretical, semi-empirical model that accurately predicts <i>ϕ</i> for various BODIPY compounds based on inexpensive electronic structure calculations, following the data-driven algorithm proposed and tested on the naphthalene family by us [Kohn, Lin, and Van Voorhis, <i>J. Phys. Chem. C.</i> <b>2019</b>, <i>123</i>, 15394]. The model allows us to identify the dominant nonradiative channel of any BODIPY molecule using its structure exclusively and to establish a correlation between the activation energy (<i>E</i><sub>a</sub>) and the fluorescence quantum yield (<i>ϕ</i><sub>fl</sub>). Based on our calculations, either the S<sub>1</sub> → S<sub>0</sub> or <i>L<sub>a</sub></i> → <i>L<sub>b</sub></i> internal conversion (IC) mechanism dominates in the majority of BODIPY derivatives, depending on the structural and electronic properties of the substituents. In both cases, the nonradiative rate (<i>k</i><sub>nr</sub>) exhibits a straightforward Arrhenius-like relation with the associated <i>E</i><sub>a</sub>. More interestingly, the S<sub>1</sub> → S<sub>0</sub> mechanism proceeds via a highly distorted intermediate structure in which the core BODIPY plane and the substituent at the 1-position are forced to bend, while the internal rotation of the very same substituent induces the <i>La </i>→<i> Lb</i> transition. Our model reproduces <i>k</i><sub>fl</sub>, <i>k</i><sub>nr</sub>, and <i>ϕ</i><sub>fl</sub> to mean absolute errors (MAE) of 0.16 decades, 0.87 decades, and 0.26, when all outliers are considered. These results allow us to validate the predictive power of the proposed data-driven algorithm in <i>ϕ</i><sub>fl</sub>. They also indicate that the model has a great potential to facilitate and accelerate the machine learning aided design of BODIPY dyes for imaging and sensing applications, given sufficient experimental data and appropriate molecular descriptors.</div>

scholarly journals Toward Prediction of Nonradiative Decay Pathways in Organic Compounds II: Two Internal Conversion Channels in BODIPYs

2019 ◽  
Author(s):  
Zhou Lin ◽  
Alexander Kohn ◽  
Troy Van Voorhis
Keyword(s):  
Quantum Yield ◽  
Rational Design ◽  
Internal Conversion ◽  
Photophysical Properties ◽  
Data Driven ◽  
Laser Dyes ◽  
Intermediate Structure ◽  
Sensing Applications ◽  
Aided Design ◽  
Semi Empirical

<div>Boron-dipyrromethene (BODIPY) molecules are widely used as laser dyes and have therefore become a popular research topic within recent decades. Numerous studies have been reported for the rational design of BODIPY derivatives based on their spectroscopic and photophysical properties, including absorption and fluorescence wavelengths (<i>λ</i><sub>abs</sub> and <i>λ</i><sub>fl</sub>), oscillator strength (<i>f</i>), nonradiative pathways, and quantum yield (<i>ϕ</i>). In the present work, we illustrate a theoretical, semi-empirical model that accurately predicts <i>ϕ</i> for various BODIPY compounds based on inexpensive electronic structure calculations, following the data-driven algorithm proposed and tested on the naphthalene family by us [Kohn, Lin, and Van Voorhis, <i>J. Phys. Chem. C.</i> <b>2019</b>, <i>123</i>, 15394]. The model allows us to identify the dominant nonradiative channel of any BODIPY molecule using its structure exclusively and to establish a correlation between the activation energy (<i>E</i><sub>a</sub>) and the fluorescence quantum yield (<i>ϕ</i><sub>fl</sub>). Based on our calculations, either the S<sub>1</sub> → S<sub>0</sub> or <i>L<sub>a</sub></i> → <i>L<sub>b</sub></i> internal conversion (IC) mechanism dominates in the majority of BODIPY derivatives, depending on the structural and electronic properties of the substituents. In both cases, the nonradiative rate (<i>k</i><sub>nr</sub>) exhibits a straightforward Arrhenius-like relation with the associated <i>E</i><sub>a</sub>. More interestingly, the S<sub>1</sub> → S<sub>0</sub> mechanism proceeds via a highly distorted intermediate structure in which the core BODIPY plane and the substituent at the 1-position are forced to bend, while the internal rotation of the very same substituent induces the <i>La </i>→<i> Lb</i> transition. Our model reproduces <i>k</i><sub>fl</sub>, <i>k</i><sub>nr</sub>, and <i>ϕ</i><sub>fl</sub> to mean absolute errors (MAE) of 0.16 decades, 0.87 decades, and 0.26, when all outliers are considered. These results allow us to validate the predictive power of the proposed data-driven algorithm in <i>ϕ</i><sub>fl</sub>. They also indicate that the model has a great potential to facilitate and accelerate the machine learning aided design of BODIPY dyes for imaging and sensing applications, given sufficient experimental data and appropriate molecular descriptors.</div>

scholarly journals Recent Progress in Metal–Organic Framework (MOF) Based Luminescent Chemodosimeters

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 974 ◽  
Author(s):  
Hao ◽  
Chen ◽  
Zhou ◽  
Zhang ◽  
Xu
Keyword(s):  
Photophysical Properties ◽  
Metal Organic Framework ◽  
Organic Ligands ◽  
Future Perspectives ◽  
Fluoride Ions ◽  
Luminescent Sensors ◽  
Sensing Applications ◽  
Redox Active ◽  
Metal Organic ◽  
Luminescent Sensing

Metal–organic frameworks (MOFs), as a class of crystalline hybrid architectures, consist of metal ions and organic ligands and have displayed great potential in luminescent sensing applications due to their tunable structures and unique photophysical properties. Until now, many studies have been reported on the development of MOF-based luminescent sensors, which can be classified into two major categories: MOF chemosensors based on reversible host–guest interactions and MOF chemodosimeters based on the irreversible reactions between targets with a probe. In this review, we summarize the recently developed luminescent MOF-based chemodosimeters for various analytes, including H2S, HClO, biothiols, fluoride ions, redox-active biomolecules, Hg2+, and CN−. In addition, some remaining challenges and future perspectives in this area are also discussed.

Novel sensing materials for harsh environment subsurface pH sensing applications

2015 ◽  
Author(s):  
Congjun Wang ◽  
Xin Su ◽  
Thomas D. Brown ◽  
Paul R. Ohodnicki
Keyword(s):  
Harsh Environment ◽  
Ph Sensing ◽  
Sensing Applications

scholarly journals Terpyridine-Functionalized Calixarenes: Synthesis, Characterization and Anion Sensing Applications

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 87
Author(s):  
Nicola Y. Edwards ◽  
David M. Schnable ◽  
Ioana R. Gearba-Dolocan ◽  
Jenna L. Strubhar
Keyword(s):  
Photophysical Properties ◽  
Binding Constants ◽  
Molar Absorptivity ◽  
Quantum Yields ◽  
Anion Sensing ◽  
Fluorescence Studies ◽  
Sensing Applications ◽  
Amide Coupling ◽  
Vis Spectroscopy ◽  
Arene Ligand

Lanthanide complexes have been developed and are reported herein. These complexes were derived from a terpyridine-functionalized calix[4]arene ligand, chelated with Tb3+ and Eu3+. Synthesis of these complexes was achieved in two steps from a calix[4]arene derivative: (1) amide coupling of a calix[4]arene bearing carboxylic acid functionalities and (2) metallation with a lanthanide triflate salt. The ligand and its complexes were characterized by NMR (1H and 13C), fluorescence and UV-vis spectroscopy as well as MS. The photophysical properties of these complexes were studied; high molar absorptivity values, modest quantum yields and luminescence lifetimes on the ms timescale were obtained. Anion binding results in a change in the photophysical properties of the complexes. The anion sensing ability of the Tb(III) complex was evaluated via visual detection, UV-vis and fluorescence studies. The sensor was found to be responsive towards a variety of anions, and large binding constants were obtained for the coordination of anions to the sensor.

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