When 1-naphthol incorporated polyvinyl alcohol (PVA) films are allowed to swell in water, there is a loss of fluorescence intensity of the neutral form with a concomitant increase of the anionic form fluorescence intensity. This fluorescence response due to the excited state prototropism (ESPT) of 1-naphthol is very sensitive to the initial stage of hydration of the PVA. Using an existing model of hydrogel swelling and DSC experiments, it was reasoned that 1-naphthol senses the bound-water component of PVA hydration. Thus, 1-naphthol is proposed as an ESPT fluorescent sensor for the specific sensing of bound-water hydration of PVA hydrogel. © 2006 Elsevier B.V. All rights reserved.

Ashok Kumar Mishra

Department Of Chemistry

Excited states

Fluorescence

Hydration

hydrogels

Polyvinyl alcohols

Proton transfer

EXCITED STATE PROTON TRANSFER

EXCITED STATE PROTOTROPISM (ESPT)

Fluorescent probe

POLYMER HYDRATION

alcohols

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Talanta

This work uses the dynamics of the excited state proton transfer of 1-naphthol to water as a basis for understanding the temperature-dependent changes in the water accessibility of the niosome membrane domain. The decrease in the neutral form fluorescence intensity of membrane bound 1-naphthol, the significant drop in the membrane-bound anion form fluorescence lifetime, and the changes in the fluorescence lifetime distribution plots of the two prototropic forms of 1-naphthol indicate a regular increase in the water penetration in the interfacial region of the niosome membrane domain, whereas the dry core regions appear unaffected with increasing temperature (10-60 °C). Unlike some liposomes and niosomes, these niosomes do not show thermotropic phase transition behavior. © 2017 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

Fulltext

New Journal of Chemistry

Temperature-dependent water penetration in Tween20:cholesterol niosome membrane: A study using excited state prototropism of 1-naphthol

Pluronics are polymeric surfactants that undergo sol-gel phase transition as a function of both temperature and concentration and have a high impact on therapeutics. An excited state proton transfer (ESPT) fluorescent molecular probe, 4-chloro-1-naphthol, has been employed to explore the sol-gel transition of pluronics in aqueous media. In aqueous homogeneous media, 4-chloro-1-naphthol shows anionic emission, whereas in heterogeneous media, it results in dual emission of its neutral and anionic forms. Moreover, variations in the intensity (I) ratio, Ineutral/Ianion, and area (A) ratio under the two individual curves, Aneutral/Aanion, faithfully reflect the progressive changes in the medium heterogeneity. The values of both Ineutral/Ianion and Aneutral/Aanion increase with increasing temperature during sol-gel phase transition and reach maxima at the phase transition temperature. Moreover, the higher values of Ineutral/Ianion and Aneutral/Aanion in 10% P123 compared to those in F127 signify a lower micro-polarity of the P123 medium compared to that of F127. Evidence of progressive dehydration is obtained from the excited state decay dynamics. It shows that the proton transfer rate decreases remarkably up to the sol-gel transition temperature and after that it remains almost constant. In the present study, thermo-reversible sol-gel transition of pluronics (P123, F127) along with the dehydration of micelles has been monitored with 4-chloro-1-naphthol. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2016.

Monitoring thermo-reversible dehydration of the pluronic microenvironment using 4-chloro-1-naphthol as an ESPT fluorescent molecular probe

1-Naphthol, an excited state acid, undergoes partial dissociation in the excited state in liposome membranes, giving rise to two peaks, as opposed to a single peak in water. The excited state prototropic equilibrium is affected by perturbations in the membrane system. This property can be used to probe the properties of biomembranes. In this respect, as a preliminary study, the partition coefficient of 1-naphthol in liposomes has been calculated.

Journal of Photochemistry and Photobiology A: Chemistry

Determination of the partition coefficient of 1-naphthol, an excited state acid, in DMPC membrane

Langmuir

Real-Time Monitoring of Polymer Swelling on the Nanometer Scale by Atomic Force Microscopy

Polymer

States of water in partially swollen poly(vinyl alcohol) hydrogels

Accounts of Chemical Research

Solvation Dynamics and Proton Transfer in Supramolecular Assemblies

Current Psychiatry Reports

Web alert

1-Naphthol as an excited state proton transfer fluorescent probe for sensing bound-water hydration of polyvinyl alcohol

Journal	Data powered by TypesetTalanta
Publisher	Data powered by TypesetElsevier
ISSN	00399140
Open Access	No