Bio-molecules are principal building blocks of living species and their inter-play is the cause of bio-activities. Various sophisticated experimental techniques as well as theoretical studies have been carried out for decades to understand the functions of bio-molecules. Fluorescence, one of the popular spectroscopic techniques has been used rigorously to follow various bio-events. However, fluorescence suffers from certain limitations due to the insufficient availability of fluorescent bio-molecules. Covalent attachment of fluorophores with different bio-molecules provides a way of overcoming this problem. Lipid, steroid, sugar, nucleic, and amino acid are the 5 main classes of bio-molecules although there are many other sub-classes. This review demonstrates the applications of such conjugated fluorescent molecular probes in different domains of biological activities. This also brings out the advantages and disadvantages of this particular type of fluorophores with the insight to the future perspectives. © 2018, © 2018 Taylor & Francis Group, LLC.

Ashok Kumar Mishra

Department Of Chemistry

Ivy Sarkar

Fluorescence

Fluorophores

Probes

Building blockes

COVALENT ATTACHMENT

Different domains

Experimental techniques

Future perspectives

Molecular Probes

Spectroscopic technique

theoretical study

Molecules

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

Fluorophore tagged bio-molecules and their applications: A brief review

Applied Spectroscopy Reviews

A new fluorescent lactose molecule (pyd-lact) (E)-1-(galactose-β-(1→4)-β-d-glucopyranosyl)-4-(1-pyrene)-but-3-en-2-one, has been synthesized by attaching 1-pyrene-but-3-ene-2-one to lactose. Extended π-conjugation removes the emission forbiddenness of pyrene, which results in the broad spectrum. Detailed photo-physical studies in homogeneous media show the sensitivity of ICT (intra molecular charge transfer) emission towards medium polarity. Unlike pyrene, pyd-lact is more soluble in water at a probe concentration of 10 μM, because of the attached disaccharide. Thus, the usage of pyd-lact as an aqueous probe is found to be advantageous over pyrene. Using the polarity sensitivity of fluorescence parameters (intensity, shift of emission maximum, anisotropy, lifetime), the micro-heterogeneity of anisotropic media such as β-CD, bile salts, and Pluronic P123 have been monitored. In contrast to pyrene-3-carboxaldehyde, which is often used as a hydrophobic fluorescent molecular probe, pyd-lact reports from the interfacial regions of micro-heterogeneous media. © 2016 The Royal Society of Chemistry.

RSC Advances

Introduction of an α,β-unsaturated carbonyl conjugated pyrene-lactose hybrid as a fluorescent molecular probe for micro-scale anisotropic media

The present work describes the synthesis and photophysical studies of two fluorescent dansylamide derivatives, in which the amine group is acylated by a long hydrophobic chain (a part of a biologically relevant palmitic acid) and by a short hydrophobic tail (a part of acetic acid). The long chain tethered dansyl analogue is successfully utilized in estimating critical micellar concentration (CMC) of bile salts (NaDC, NaC) as well as anionic and cationic surfactants (SDS, CTAB) with the help of enhanced fluorescence intensity facilitated by better solubilization of the molecule in microheterogeneous media. The long chain tethered dansylamide derivative shows significant fluorescence solvatochromism with a red shift (ca. 4000 cm-1) from hexane to water. In contrast, the solvatochromism exhibited by the parent/short acyl chain analogue is much less (ca. 2230 cm-1 from hexane to water) and the fluorescence is not sensitive to micellization. Interestingly, the long chain tethered fluorescent probe shows high sensitivity towards premicellar aggregation of sodium deoxycholate (NaDC) bile salt, through a clear blue shift of emission maxima and concomitant enhancement of fluorescent intensity. Such an observation of fluorescence sensing of premicellar aggregation is unusual. © the Owner Societies 2015.

Physical Chemistry Chemical Physics

Fluorescence of N-acylated dansylamide with a long hydrophobic tail: Sensitive response to premicellar aggregation of sodium deoxycholate

A new fluorescent cholesterol molecular probe, 3-acetyl-7-(diethylamino)-2H-chromen-2-one attached cholesterol (Cum-Chl), has recently been introduced as a reporter of micro-heterogeneous media. The H-aggregate forming ability of Cum-Chl provides a useful fluorescence parameter, Imonomer/Iaggregate to understand the micro-polarity of anisotropic media. Pluronics are surfactant based polymeric anisotropic media having important applications in therapeutics. Being a sensitive indicator of pluronics micro-polarity Imonomer/Iaggregate can help in selecting pluronics for medicinal purposes. Additionally, temperature and concentration induced sol-gel transition of pluronics (P123, F127) have been successfully investigated by Cum-Chl using its Imonomer/Iaggregate value, along with other conventional fluorescence parameters. Finally, this molecular probe, Cum-Chl emerges as a good sensor of progressive polymeric association and micro-polarity of pluronics. © 2015 The Royal Society of Chemistry.

Utilizing an aggregate forming microenvironment sensitive coumarin-cholesterol conjugate as a sensor of pluronic organization and micro-polarity

A new fluorescent pyrene-glucose conjugate (pyd-glc), 1-(4,6-O-butylidene-β-d-glucopyranosyl)-4-(1-pyrene)-butan-2-one, has been synthesized by attaching a pyrene molecule to acetal (butylidene) protected glucose via a butane-2-one linker. Detailed photo-physical studies of pyd-glc in homogeneous media have been carried out in both protic and aprotic solvents which lead to a py scale, a solvent polarity scale specific to this molecule, like that of pyrene. The molecule aggregates in water and partitions as a monomer in micro-heterogeneous media. The photo-physical response of pyd-glc has been studied in various sugar and non-sugar based micro-heterogeneous media. Similar to pyrene, this molecule offers multiple fluorescence parameters to investigate the organization of micro-heterogeneous media. The fluorescence parameters of pyd-glc faithfully reflect the state of organization of these anisotropic media. © The Royal Society of Chemistry 2015.

Fulltext

Synthesis and evaluation of a glucose attached pyrene, as a fluorescent molecular probe in sugar and non-sugar based micro-heterogeneous media

Capsaicin is an ingredient of a wide variety of red peppers, and it has various pharmacological and biological applications. The present study explores the interaction of capsaicin with dimyristoylphosphatidylcholine (DMPC) lipid bilayer membrane by monitoring various photophysical parameters using its intrinsic fluorescence. In order to have a clearer understanding of the photophysical responses of capsaicin, studies involving (i) its solvation behavior in different solvents, (ii) the partition coefficient of capsaicin in different thermotropic phase states of lipid bilayer membrane, and (iii) its location inside lipid bilayer membrane have been carried out. Capsaicin has a reasonably high partition coefficient for DMPC liposome membrane, in both solid gel (2.8 ± 0.1 × 105) and liquid crystalline (2.6 ± 0.1 × 105) phases. Fluorescence quenching study using cetylpyridinium chloride (CPC) as quencher suggests that the phenolic group of capsaicin molecule is generally present near the headgroup region and hydrophobic tail present inside hydrophobic core region of the lipid bilayer membrane. The intrinsic fluorescence intensity and lifetime of capsaicin sensitively respond to the temperature dependent phase changes of liposome membrane. Above 15 mol %, capsaicin in the aqueous liposome suspension medium lowers the thermotropic phase transition temperature by about 3 °C, and above 30 mol %, the integrity of the membrane is significantly lost. © 2015 American Chemical Society.

Journal	Data powered by TypesetApplied Spectroscopy Reviews
Publisher	Data powered by TypesetTaylor and Francis Inc.
ISSN	05704928
Open Access	No