Jyotirmayee Mohanty

• Bhabha Atomic Research Centre

In order to address the air quality issues and industrial gas leakages effectively, gas sensors must be highly sensitive, selective, stable, cost‐effective, and with high life time. We present here a facile solvothermal method to synthesize a Cu based metal‐organic framework (Cu‐MOF‐74) and demonstrated its potential as a selective fluorescent prob...

Perylene diimide (PDI) derivatives have been extensively explored as chromophoric dyes for functional organic materials. Here, the custom synthesized tyrosine appended perylene diimide (PDI‐Tyr) derivative has shown strong aggregation in aqueous medium diminishing its emissive features, which was surpassed by the supramolecular interaction with β‐c...

With growing threats from counterfeiting‐based security breaches, multi‐level and specific stimuli‐responsive anti‐counterfeiting devices and message encryption methods have attracted immense research interest. Fluorescence‐based encryption from aggregation‐induced emission (AIE)‐based materials solves the problems to a considerable extent. However...

With growing threats from counterfeiting‐based security breaches, multi‐level and specific stimuli‐responsive anti‐counterfeiting devices and message encryption methods have attracted immense research interest. Fluorescence‐based encryption from aggregation‐induced emission (AIE)‐based materials solves the problems to a considerable extent. However...

Surface-functionalized noble metal nanoparticles with macrocyclic hosts have attracted enormous research interest owing to their applications in drug delivery, catalysis, bioimaging, etc. Stable p-sulfonatocalix[6]arene-functionalized gold nanoparticles (SCx6AuNPs) of the sizes ∼7.5 nm have been synthesized and characterized by using UV–vis absorpt...

H2 is one of the most attractive fuel alternatives to the existing fossil fuels that cause detrimental environmental issues. Thus, there has been an upsurge in the research on the production of green hydrogen. In this view, cucurbit[7]uril (CB7)-functionalized Co:Ni alloy nanocomposites with different compositions, reported here for the first time,...

This review article focuses on the supramolecular assemblies fabricated through host-guest interaction using macrocycles such as cyclodextrins, calixarenes and cucurbiturils as hosts. Though several review articles have appeared on such host-guest assemblies having importance in controlled drug-delivery, fluorescence on-off sensors, catalysis etc.,...

Owing to their distinctive physical and chemical properties, tunable by derivatization, Perylenediimide (PDI) chromophores find diverse applications not only as chemosensors, inorganic-organic semiconductors, photovoltaics, photocatalysis etc., but also attracted applications...

Coumarins, in general, exhibit a wide range of photophysical characteristics and are highly sensitive to their microenvironment, and, therefore, their fluorescence characteristics have attracted immense attention as sensors in chemical and biological systems. In the present study, the supramolecular interaction of a bichromophoric coumarin dye, nam...

Abnormal cell growth leading to cancer is a major concern and warrants an easy and early diagnosis strategy. In this regard, spectroscopic distinction of non-cancerous and syngeneic cancerous tissues has been demonstrated by label-free fluorescence and circular dichroism (CD) spectral features of a probe dye, thiazole orange (TO), on binding to gen...

Precise control over the stimuli-responsive noncovalent interactions operative in a complex molecular system has emerged as a convenient way to realize applications in the detection and sensing of trace analytes, metal ion separation, uptake-release, in situ nanoparticle synthesis, and catalytic activity. This feature article focuses on the attribu...

Editorial on the Research Topic Frontiers in Chemistry-Rising Stars: Asia Rising Stars: Asia is dedicated to collecting the high-quality work of outstanding researchers in the early stages of their independent careers, working across the Asian continent including the countries like China, India, Saudi Arabia, South Korea, Jordan, and Pakistan in th...

Confinement of small guest molecules in cavitands or organized assemblies offers a convenient strategy to modulate the physicochemical properties of the guests and has proved very effective in influencing/controlling the course and outcome of the reaction path. Research literature has seen incredible contribution on the confinement effect on small...

The ability of polyanionic molybdate to inhibit and degrade protein fibrils both in vitro (insulin protein) and in vivo (Drosophila fly model) has been demonstrated.

This review article discusses the non-covalent interaction of various probe molecules of different structural diversity with G-quadruplex forming Guanine rich DNA sequences, revealing remarkable stimuli responsive fluorescence changes which are appropriate for sensing and other technological applications. Tailor-made probes having quadruplex induci...

Ammonia borane (AB) is considered a potential “on-board” hydrogen storage material. However, its implementation as a hydrogen reservoir in fuel cells is lacking due to the extremely slow release of hydrogen at room-temperature hydrolysis. In this study, a metal-free supramolecular strategy is demonstrated at room temperature to increase the hydroly...

Supramolecularly assembled building blocks, especially those based on π stacked organic or inorganic redox active materials have found encouraging applications in recent years due to their electron-accepting nature and easy structural manipulations. In this regard, by employing various spectroscopic, thermodynamic and imaging measurements we establ...

This study explores the complexation and fluorescence quenching of lumichrome (LC), a structural analogue of the biologically important flavin molecules, with a macrocyclic host, p-sulfonatocalix[6]arene (SCX6). It is revealed that the fluorescence quenching involves both static and dynamic interactions and occurs due to photoinduced electron trans...

The noncovalent host–guest interaction of sanguinarine (SGR), a benzophenanthridine alkaloid, with a nontoxic, water soluble sulfobutylether-β-cyclodextrin (SBE7βCD, commercially available as Captisol) macrocyclic host has been investigated using ground-state optical absorption, and steady-state and time-resolved fluorescence measurements. The pH-d...

The supramolecular interaction of cyclodextrin homologues with a pyrene-armed calixarene has been investigated. p-tert-Butylcalix[4]arene-di-4-(pyren-1-yl)butanoic acid (PCX4) has been synthesized and characterized by 1H NMR, FT-IR and mass spectrometry. The modulation in the photophysical properties, especially the monomer and excimer emission beh...

In this study, Bi3+ incorporation in NaYbF4:Er lattice and its influence on upconversion luminescence properties have been investigated in detail using techniques such as temperature‐dependent luminescence, Fourier transform infrared spectroscopy and X‐ray diffraction (XRD). The study was carried out to develop phosphors with improved upconversion...

The amelioration of antibacterial efficacy along with the reduced minimum inhibitory concentration (MIC) of sanguinarine (SGR) drug have been demonstrated through the uptake of SGR by p-sulfonatocalix[6]arene-functionalized silver nanoparticles. The...

Deaggregated perylenediimide (PDI) derivatives exhibit exceptionally high quantum yields, photostability and appropriate molecular features for organic electronics. This work demonstrates a metal–dye–metal framework with a large and stable negative differential resistance (NDR) at ambient conditions, built using a supramolecular strategy. The deagg...

Construction of smart materials based on supramolecular interactions has received considerable research interest owing to their potential applications in energy storage, photonic devices, drug delivery vehicles, sensors as well as therapeutics. In this context, research literature has seen tremendous contributions on the supramolecular assemblies o...

Modulation and control of stimuli responsive features of molecular assemblies in organized assemblies/cavitand macrocycles have received immense attention in many areas. In this study, we have established the formation of a discrete molecular assembly of thiazole orange (TO) dyes at the portals of the sulfobutylether β‐cyclodextrin (SBE7βCD) macroc...

Two red-emitting water-soluble fluorophores bearing a coumarin scaffold were synthesized and their interactions with cucurbit[7]uril [CB7] were investigated. A significant red-shift in the absorption spectra showed the interaction of coumarin dyes with the carbonyl portals of CB[7]. The formation of supramolecular complex is substantiated by the ch...

Porphyrins, especially the 5,10,15,20-tetrakis(4-N-methylpyridyl) porphyrin (TMPyP), are well-accepted as photosensitizers due to strong absorption from visible to near-infrared region, good singlet oxygen quantum yields as well as chemical versatility, all of which can be further modulated through planned supramolecular strategies. In this study,...

The host-guest interactions of a third-generation fluoroquinone, danofloxacin (DOFL), with the macrocyclic host cucurbit[7]uril (CB7) have been investigated at different pH values (~3.5, 7.5, and 10). The photophysical properties have been positively affected, that is, the fluorescence yield and lifetime increased, as well as the photostability of...

Perylenediimide (PDI) chromophores with redox-active groups have facilitated the construction of several novel functional materials. For the first time, unusual spectroscopic changes and differential binding behaviour of a tetracationic ethyl viologen tethered PDI derivative, PDEV, with calf-thymus DNA (ct-DNA) is reported here and is ascertained a...

Although aqueous dye lasers are much sought after, they have been of no practical use, as laser dyes show a strong tendency for aggregation in water, thus diminishing their optical output. Contributing towards this shortcoming, we studied the noncovalent interactions of two prominent laser dyes, namely, rhodamine 6G and rhodamine B, with a water so...

The interaction between red-emitting pyridinium derivative [4-((1E,3E)-4-(4-(dimethylamino)phenyl)buta-1,3-dien-1-yl)-1-methylpyridin-1-ium] (DABP) and cucurbit[7]uril was investigated using optical absorption, steady-state and time-resolved fluorescence and anisotropy measurements. The changes in the UV/Vis absorption, fluorescence spectral charac...

Stimuli-responsive molecular assemblies of potential drug/guest molecules through non-covalent host-guest interaction have been found very attractive in transporting and releasing the desired form on demand. In this review article, the supramolecular interaction of a biologically important dye Hoechst-33258 (H33258) has been investigated in aqueous...

Construction and characterization of stimuli-responsive supra-biomolecular nanoassembly between cucurbit[7]uril (CB7) and bovine serum albumin (BSA), uptake and release of doxorubicin (DOX) in live cells, the enhanced sensitivity of brilliant green (BG) and the metal ion-induced relocation of neutral red (NR) dye to BSA have been discussed in this...

The noncovalent host-guest interactions of the cationic (AcH+) and neutral (Ac) forms of the acridine dye with the macrocyclic hosts such as cucurbit[7]uril (CB7) and cucurbit[8]uril (CB8) have been investigated to evaluate the effect of cavity size on the photophysical properties and the protolytic equilibrium of acridine dye. The cationic form un...

Anomalous aggregation of proteins into amyloid fibrils leads to various amyloidosis diseases including neurodegenerative disorders. Inhibition of fibrillation process and rupture of mature amyloid fibril/plaques using small organic molecules are the promising remedial strategies to combat neurodegenerative diseases. In this study, we present sulfob...

Host-guest interaction of macrocyclic receptor, cucurbit[8]uril (CB8), with neutral bichromophoric coumarin 30 (C30) dye has been investigated using various spectroscopic tools. Absorption and fluorescence emission results along with ¹H NMR data have demonstrated the existence of host-guest complex of C30 dye with CB8 host in a 1:2 and 3:2 (CB8:C30...

Supramolecular interaction of cyclodextrin homologues with a pyrene-armed calixarene has been investigated. p-tert-butylcalix[4]arene-di-4-(pyren-1-yl)butanoic acid (PCX4) has been synthesized and characterized by 1H NMR, FT-IR and Mass spectrometry. The modulation in the photophysical properties, especially, the monomer and excimer emission behavi...

The host-guest interactions and the consequent modulation in the prototropic equilibrium of a phenazine dye, neutral red, with p-sulfonatocalix[4]arene (SCX4) and p-sulfonatocalix[6]arene (SCX6) macrocyclic hosts have been investigated. Both the neutral (NR) and cationic (NRH+) forms of the dye formed inclusion complexes with SCX6, with the larger...

Amyloid fibrils are formed by the aberrant aggregation of proteins into highly ordered β-sheet structures and are believed to be the root cause of several neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Prion diseases, etc. and have been the subject of extensive biochemical, biophysical and clinical studies. Developing...

We report the construction of a non-toxic nanoassembly of bovine serum albumin (BSA) protein and the cucurbit[7]uril macrocycle as well as its stimuli-responsive breakage with adamantylamine or pH, which restores the protein structure and recognition properties. The assembly showed efficient loading and controlled release of a standard drug, doxoru...

A viologen-perylenediimide conjugate, termed as PDEV, is prepared for efficient base sensing. The conjugate is showing solvatochromic behavior as well. The base-sensitivity of viologen is purposefully coupled with the emission property of perylenediimide (PDI) in order to lower the detection limit. PDEV has shown base sensing ability in the ppb lev...

We report the construction of a non-toxic nanoassembly of BSA protein and cucurbit[7]uril macrocycle and its stimuli-responsive breakage with adamantylamine or pH, which restores the protein structure and recognition properties. The assembly showed efficient loading and controlled release of a standard drug, doxorubicin (DOX), and the same was vali...

Therapeutically improved long acting insulin preparations requires in-depth understanding of the hexamer assembly, structural selectivity and its stability in solution. This article demonstrates, for the first time, an efficient method for the hexamerization of human insulin by a structure specific triphenylmethane (TPM) dye, the Ethyl Violet (EV),...

We report the construction of a novel non-covalently held cucurbit[7]uril-heptamolybdate hybrid material for the first time, and demonstrate its application as a generator bed for the facile and efficient separation of 99mTc radiotracer, which is in demand for several theranostic applications.

The interaction between a biologically important dye, 4′,6-diamidino-2-phenylindole (DAPI) and a macrocyclic host, p-sulfonatocalix[6]arene (SCX6) has been investigated using ground-state absorption, steady-state as well as time-resolved fluorescence measurements at two preset pH conditions: 2.5 and 6. Acknowledging the complexation with SCX6 at bo...

This study reveals the intriguing photophysics of lumichrome (LC) in two types of organized assemblies, namely, normal micelles and reverse micelles, formed by the cationic surfactant, benzyldimethylhexadecylammonium chloride (BHDC). Although LC exists in alloxazine form at around neutral pH in aqueous solutions, in BHDC micelles and reverse micell...

We reveal the ability of p-sulfonatocalix[4/6]arene to effectively inhibit the fibril formation in human insulin and demonstrate its potential to disintegrate the mature fibrils, a promising supramolecular strategy to combat amyloidosis.

The noncovalent interaction between 4', 6-diamidino-2-phenylindole (DAPI) and sulfobutyl ether β-cyclodextrin (SBE7β-CD) has been evaluated by using photochemical measurements and equated with that of native β-CD. Contrasting recognition and intriguing modulations in the photochemical behaviors of DAPI, especially, large enhancement in the fluoresc...

We report supramolecular control and mechanism for the contrasting dimer emission from selected bichromophoric coumarin dyes, caught in the cucurbit[8]uril cavity; a facile approach for photo-responsive molecular assemblies through structural tuning.

The research on the chemistry of host–guest complexes based on noncovalent interactions involving a macrocyclic host and a guest has seen an upsurge in recent years due to their potential application in metal ion separation, molecular sensors, catalysis, nanomaterials and therapeutics, and other stimuli-responsive systems. This article provides a b...

The research on the G-quadruplex DNAs has received much attention in recent years and numerous reports appeared probing its detection, structure, stability, reactivity, selectivity, etc. for the chemical intervention of its biological activity or sensor applications. This feature article provides an account of the recent reports from different rese...

The formation of molecular superstructures by metal ion-mediated noncovalent self-assembly has been demonstrated, using the macrocycle, cucurbit[7]uril (CB7) and the dye, thiazole orange (TO) as building blocks. Interestingly, the association of these molecular building blocks can be tuned by the chemical environment, leading to self-assembled stru...

Supramolecular host-guest interaction of cationic oxazine-1 (OX1) dye with two cucurbit[n]uril (CBn) hosts, namely CB7 and CB8, has been investigated using photophysical and quantum chemical studies. Both CB7 and CB8 display much stronger binding affinities for OX1 dye compared to conventional cyclodextrin (CD) hosts, arises due to strong ion-dipol...

The intriguing dual-emission behavior of p- dimethylaminobenzonitrile (DMABN) and the identity of the associated excited states is, arguably, the most extensively investigated and also controversially discussed molecule- specific phenomenon of modern photochemistry. We have now found a new, third fluorescence band when DMABN is encapsulated within...

This article provides a brief account of the supramolecular chemistry of host-guest interactions and their binding mechanisms. The characterization of host-guest complexes, especially those based on cucurbituril (CB) macrocycles, by different methods such as absorption/fluorescence spectroscopy, 1H NMR, mass spectrometry, and isothermal titration c...

The optical, electrochemical, morphology as well as surface free-energies of poly[(9,9-dioctylfluorene-alt-bithiophene/cucurbit[7]uril)] (PF-BT•CB7) have been investigated and compared with those of the reference PF-BT. The absorption of PF-BT•CB7 and PF-BT extend beyond 500 nm; the maxima appear at 390 and 450 nm, respectively. The fluorescence qu...

Interaction between meso-tetrakis(N-methylpyridinyl)porphyrin (TMPyP) and single strand DNA homopolymers, (dA)40, (dT)40, (dG)40 and (dC)40, has been investigated using absorption, fluorescence and circular dichroism (CD) measurements. Fluorescence intensity of TMPyP is quenched in the presence of (dG)40 due to photo-induced electron transfer from...

This article presents the process and mechanism of supramolecular pKa shift in two bichromophoric coumarin laser dyes, namely, Coumarin 7 (C7), (pKa 4.6) and Coumarin 30 (C30), (pKa 3.0) achieved by introducing a synthetic macrocyclic receptor, cucurbit[7]uril (CB7), in aqueous media. The intramolecular charge transfer in these coumarin dyes, fro...

This article demonstrates, for the first time, construction of novel cucurbituril (CB)-adorned supramolecular micellar assemblies of a cationic surfactant, cetylpyridinium chloride (CPC), through noncovalent host-guest interactions. The distinct cation receptor features and cavity dimensions of the CB5 and CB7 homologues assert that the macrocyclic...

This review article provides an account on the supramolecular pK a shifts of cucurbit[7]uril-based assemblies of three chromophoric dyes, coumarin 6, Hoechst 33258 and neutral red. Since cucurbituril macrocycles act as cation-receptors due to the presence of two identical negatively polarized carbonyl portals, they preferentially encapsulate the pr...

Stimuli-responsive molecular assemblies of potential drug/guest molecules through non-covalent host-guest interaction have found very attractive in transporting and releasing the desired form on demand. In this article, the host-guest interaction of a drug, Hoechst-33258 (H33258) has been investigated in aqueous solutions in presence of a macrocycl...

The quest for a G-quadruplex specific fluorescent sensor amongst other DNA forms under physiological salt conditions has been addressed in this article. We demonstrate for the first time the application of a water soluble fluorogenic dye, Thioflavin T (ThT), in dual role of exclusively inducing quadruplex folding in the 22AG human telomeric DNA, bo...

Supramolecular host–guest interactions of oxazine-1 dye with β- and γ-cyclodextrins (βCD and γCD, respectively) have been investigated in neutral aqueous solution (pH 7) at ambient temperature (25 °C) following absorption, fluorescence, and circular dichroism measurements. The dye forms inclusion complexes with both CDs, causing significant changes...

Non-covalent interaction of coumarin laser dyes, namely coumarin-1 (C1), coumarin-481 (C481) and coumarin-6H (C6H), with a versatile macrocyclic host molecule cucurbit[7]uril (CB7), has been investigated in aqueous solution using photophysical methods. Steady-state and time-resolved fluorescence studies illustrate significant enhancements/modificat...

Laser flash photolysis studies were carried out on two types of silver nanoparticles prepared byγ-radiolysis of Ag+ solutions in the presence of polyphosphate as the stabiliser. Type I silver nanoparticles displayed a surface plasmon band at 390 nm. Type II silver nanoparticles showed a 390 nm surface plasmon band with a shoulder at 550 nm. On phot...

This article reports an efficient host-assisted guest protonation mechanism in coumarin 6 (C6) dye, upon its interaction with cucurbit[7]uril (CB7) macrocycle. C6 uptakes the CB7 macrocycle both in 1:1 and 2:1 (CB7/C6) stoichiometries, which brings out a large upward pK(a) shift (from ~0.8 to 6), and facilitates the protonation of C6 at normal pH c...

Using human insulin, we report for the first time, the evaluation of fluorescence lifetime of an extrinsically added fluorogenic dye, Thioflavin T (ThT), as a more sensitive and convenient method for the assessment of fibrillation in the pre-fibrillar regime.

Supramolecular host-guest interaction is an interesting strategy for inflicting changes in the photophysical properties of suitable guest molecules, without any covalent modifications. This review focuses on the different effects of two macrocyclic hosts, beta-cyclodextrin (b-CD) and cucurbit[7]uril (CB7), on the photophysical properties of the bio...

This article reports a convenient supramolecular strategy to construct fluorescent photoswitchable molecular assemblies between a macrocyclic host, cucurbit[8]uril (CB8), and a fluorogenic dye, thiazole orange (TO). The interaction mechanism and the stable stoichiometric host-guest arrangements have been claimed on the basis of the optical absorpti...

The aggregation behavior of the DNA marker dye thiazole orange (TO), has been investigated in two types of surfactant assemblies, namely, premicelles/micelles of sodium dodecyl sulfate (SDS) and pre reverse micelles/reverse micelles of sodium bis(2-ethylhexyl) sulfosuccinate (AOT). In the case of an SDS/water system, absorption spectral changes of...

A facile supramolecular approach to prepare surface functionalized silver nanoparticle conjugates has been established and their enhanced molecular recognition features have been explored to demonstrate the uptake and stimulus responsive release of a phototherapeutic porphyrin dye, the TMPyP.

This Feature Article provides an account of the recent work by our research group (with some reference to relevant work of other groups) on the spectacular physico-chemical properties of cucurbituril-based supramolecular assemblies of chromophoric dyes having technological and biological importance. Simultaneous association of multiple hosts or gue...

Molecular assemblies of potential guest molecules through non-covalent host-guest interactions have found immense use in many applied areas. In this study supramolecular interaction of a biologically important dye Hoechst-33258 (H33258) has been investigated in aqueous solutions at different pHs, in the presence of a macrocyclic host, namely, cucur...

Of late, molecular-recognition-guided supramolecular assembly and its relevance in the development of highly stable and active photofunctional materials have drawn much attention. In this review, the non-covalent interaction of a biologically important dye, thioflavin T (ThT), with cucurbituril macrocycles, especially, cucurbit[7]uril (CB7) and cuc...

A water-based narrow-band high-efficiency dye laser was designed by means of a supramolecular host-guest chemical approach. The lasing characteristics of rhodamine B and sulforhodamine B (Kiton Red S) dyes in aqueous solution with the macrocyclic host cucurbit[7]uril (CB7) as additive were investigated in a narrow-band dye laser setup. Significant...

The photophysical behavior of Hoechst 33258 (H33258) in aqueous solution has been studied by steady-state and time-resolved fluorescence measurements. The intriguing intramolecular geometrical orientations of the dye bring out major modulation on its photophysical behavior, especially in the fluorescence emission characteristics with pH. It has bee...

The interaction of the macrocyclic host, cucurbit[7]uril (CB7), with riboflavin (RF) and its derivative, flavin adenine dinucleotide (FAD), has been investigated using absorption and steady-state and time-resolved fluorescence measurements. Interestingly, in the presence of CB7, the fluorescence intensity of RF is quenched, whereas the fluorescence...

Interactions among macrocyclic hosts and dyes/drugs have been explored extensively for their direct usage in controlled uptake and release of large number of potential drug molecules. In this paper we report the non-covalent interaction of cucurbit[8]uril macrocycle (CB8) with a biologically important dye, neutral red, by absorption and fluorescenc...

Modulation in the photophysical properties and intramolecular electron transfer behavior of the flavin adenine dinucleotide (FAD) molecule has been investigated in the presence of the macrocyclic hosts, alpha-, beta- and gamma-cyclodextrins (CDs), using absorption and steady-state and time-resolved fluorescence measurements. The results demonstrate...

We report an intriguing noncovalent interaction of thioflavin T (ThT), a fibril diagnostic dye, with the versatile macrocyclic host molecule cucurbit[7]uril (CB7) in the presence of metal cations. ThT forms both 1:1 (CB7.ThT) and 2:1 [(CB7)(2).ThT] complexes with CB7 host, leading to specific structural arrangements. Addition of competitive guests...

Solvent polarity effect on the photophysical properties of two newly synthesized aminostyryl-thiazoloquinoxaline dyes, one with a flexible diphenylamino group, namely, N,N-diphenyl-4-[2-(thiazolo[4,5-b]quinoxalin-2-yl)vinyl]aniline (TQ1), and the other with a rigid julolidinylamino group, namely, (9-[2-(thiazolo[4,5-b]quinoxalin-2-yl)vinyl]julolidi...

The effect of the macrocyclic host, cucurbit[7]uril (CB7), on the photophysical properties of the 2-(2'-hydroxyphenyl)benzimidazole (HPBI) dye have been investigated in aqueous solution by using ground-state absorption and steady-state and time-resolved fluorescence measurements. All three prototropic forms of the dye (cationic, neutral, and anioni...

The control over the supramolecular excimer assembly between a benzthiazolium dye, thioflavin T (ThT) and a macrocyclic host cucurbit[8]uril (CB8) was studied. Significant spectral changes were observed on introducing the macrocyclic host CB8 to the ThT solution. The absorption band initially shifted from 412 to 445 nm on gradual increase in the CB...

Noncovalent interaction of Thioflavin T (ThT) with versatile macrocyclic host molecules, namely, cucurbit[7]uril (CB7) and cucurbit[5]uril (CB5), has been investigated in aqueous solutions by photophysical methods. Steady-state and time-resolved fluorescence studies illustrate significant enhancements/modifications in the ThT fluorescence yield, li...

Noncovalent interaction of two water-soluble synthetic macromolecules, Cucurbit[7]uril (CB7) and 5,10,15,20-tetrakis(4- N-methylpyridyl)porphyrin (TMPyP), has been studied from the viewpoint of organizing them through supramolecular interactions and thereby modulating their functional activities. Steady-state and time-resolved fluorescence measurem...

Effect of donor amine orientation on nondiffusive ultrafast intermolecular electron transfer (ET) reactions in coumarin-amine systems has been investigated using femtosecond fluorescence upconversion measurements. Intermolecular ET from different aromatic and aliphatic amines used as donor solvents to the excited coumarin-151 (C151) acceptor occurs...

The binding affinity of Neutral Red with cucurbit[7]uril (CB7) can be fine-tuned by addition and competitive binding of metal ions, which leads also to a pK(a) shift of the dye; this can be exploited to relocate the dye from the macrocyclic cavity of CB7 to the biomolecular pocket of bovine serum albumin.

Ground state absorption and steady-state and time-resolved fluorescence measurements have been carried out to understand the host-guest interactions of p-diethylaminobenzonitrile (DEABN) and p-dimethylaminobenzonitrile (DMABN) dyes with alpha-cyclodextrin (alpha-CD) and beta-cyclodextrin (beta-CD) hosts. DEABN and DMABN dyes show both locally excit...

The host-guest interactions of the neutral (AO) and cationic (AOH+) forms of the dye acridine orange with the macrocyclic hosts cucurbit[7]uril (CB7) and beta-cyclodextrin (beta-CD) were investigated by using ground-state absorption and steady-state as well as time-resolved fluorescence measurements. The cationic form undergoes no significant compl...

The host-guest interactions of the neutral (AO) and cationic (AOH+) forms of the dye acridine orange with the macrocyclic hosts cucurbit[7]uril (CB7) and beta-cyclodextrin (beta-CD) were investigated by using ground-state absorption and steady-state as well as time-resolved fluorescence measurements. The cationic form undergoes no significant compl...

Interactions of two hydroxycalixarenes (HOCXs) and their alternate methoxy derivatives (MOCXs) with different proton acceptors (PA) like urea (U; pKb = 13.9), N-methylurea (MU; pKb = 13.1), and triethylamine (TEA; pKb = 3.19) have been investigated using absorption and fluorescence measurements, to understand the role of intramolecular hydrogen bon...