Tryptophan Fluorescence Yields and Lifetimes as a Probe of Conformational Changes in Human Glucokinase.

Five variants of glucokinase (ATP-D-hexose-6-phosphotransferase, EC 2.7.1.

Fluorescence lifetime imaging with time-gated detection of hyaluronidase using a long lifetime azadioxatriangulenium (ADOTA) fluorophore.

A fluorescence lifetime imaging probe with a long lifetime was used in combination with time-gating for the detection of hyaluronidase using hyaluronic acid as the probe template. This probe was developed by heavily labeling hyaluronic acid with long lifetime azadioxatriangulenium fluorophores (ADOTA). We used this probe to image hyaluronidase produced by DU-145 prostate cancer cells.

Fluorescent biosensor for the detection of hyaluronidase: intensity-based ratiometric sensing and fluorescence lifetime-based sensing using a long lifetime azadioxatriangulenium (ADOTA) fluorophore.

In this report, we have designed a rapid and sensitive, intensity-based ratiometric sensing as well as lifetime-based sensing probe for the detection of hyaluronidase activity. Hyaluronidase expression is known to be upregulated in various pathological conditions. We have developed a fluorescent probe by heavy labeling of hyaluronic acid with a new orange/red-emitting organic azadioxatriangulenium (ADOTA) fluorophore, which exhibits a long fluorescence lifetime (∼20 ns).

Rationalizing the use of functionalized poly-lactic-co-glycolic acid nanoparticles for dendritic cell-based targeted anticancer therapy.

Background: Delivery of PLGA (poly [D, L-lactide-co-glycolide])-based biodegradable nanoparticles (NPs) to antigen presenting cells, particularly dendritic cells, has potential for cancer immunotherapy.

Materials & Methods: Using a PLGA NP vaccine construct CpG-NP-Tag (CpG-ODN-coated tumor antigen [Tag] encapsulating NP) prepared using solvent evaporation technique we tested the efficacy of ex vivo and in vivo use of this construct as a feasible platform for immune-based therapy.

Results: CpG-NP-Tag NPs were avidly endocytosed and localized in the endosomal compartment of bone marrow-derived dendritic cells.

A triazine-based BODIPY trimer as a molecular viscometer.

Photophysical behaviour of a novel trimeric BODIPY rotor with a high extinction coefficient is reported. Steady state and time resolved fluorescence measurements established that the trimer could be used as a viscometer for molecular solvents, membrane-like environments and several cancer cell lines.

Steady State and Time Resolved Fluorescence Studies of Azadioxatriangulenium (ADOTA) Fluorophore in Silica and PVA Thin Films.

A cationic azadioxatriangulenium (ADOTA) dye was entrapped in silica thin films obtained by the sol-gel process and in poly (vinyl) alcohol (PVA) thin films. Azadioxatriangulenium is a red emitting fluorophore with a long fluorescence lifetime of ~20 ns. The fluorescent properties of azadioxatriangulenium in silica thin films and PVA films were studied by means of steady-state and time resolved fluorescence techniques.

Effect of Quencher, Denaturants, Temperature and pH on the Fluorescent Properties of BSA Protected Gold Nanoclusters.

In this paper, we have synthesized BSA protected gold nanoclusters (BSA Au nanocluster) and studied the effect of quencher, protein denaturant, pH and temperature on the fluorescence properties of the tryptophan molecule of the BSA Au nanocluster and native BSA. We have also studied their effect on the peak emission of BSA Au nanoclusters (650 nm). The phtophysical characterization of a newly developed fluorophore in different environments is absolutely necessary to futher develop their biomedical and analytical applications.

Evidence of Energy Transfer from Tryptophan to BSA/HSA Protected Gold Nanoclusters.

This work reports on the chromophores interactions within protein-protected gold nanoclusters. We conducted spectroscopic studies of fluorescence emissions originated from gold nanoclusters and intrinsic tryptophan (Trp) in BSA or HSA proteins. Both, steady state fluorescence and lifetime measurements show a significant Forster resonance energy transfer (FRET) from Trp to the gold nanocluster.

Evidence of energy transfer from tryptophan to BSA/HSA protected gold nanoclusters.

This work reports on the chromophores interactions within protein-protected gold nanoclusters. We conducted spectroscopic studies of fluorescence emissions originated from gold nanoclusters and intrinsic tryptophan (Trp) in BSA or HSA proteins. Both steady state fluorescence and lifetime measurements showed a significant Forster Resonance Energy Transfer (FRET) from Trp to the gold nanocluster.

Associated anisotropy decays of ethidium bromide interacting with DNA.

Ethidium Bromide (EB) is a commonly used dye in a deoxyribonucleic acid (DNA) study. Upon an intercalation, this dye significantly increases its brightness and fluorescence lifetime. In this report we have studied the time resolved fluorescence properties of EB existing simultaneously in free and DNA-bound forms in the solution.

Associated Anisotropy Decays of Ethidium Bromide Interacting with DNA.

Ethidium Bromide (EB) is a commonly used dye in a deoxyribonucleic acid (DNA) study. Upon an intercalation, this dye significantly increases its brightness and fluorescence lifetime. In this report we have studied the time-resolved fluorescence properties of EB existing simultaneously in free and DNA-bound forms in the solution.

Two Photon Induced Luminescence of BSA Protected Gold Clusters.

In this short letter, we have synthesized the BSA protected Au nanoclusters and studied their two photon luminescence behavior. We demonstrate that BSA Au nanoclusters can be used as a probe with two photon excitation capability. Our results show a quadratic relation between excitation power and emission intensity whereas with one photon excitation shows a linear dependence.

Polarization properties of fluorescent BSA protected Au25 nanoclusters.

BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and studied their steady state and time resolved fluorescence properties including polarization behavior in different solvents: glycerol, propylene glycol and water.

FRET based ratio-metric sensing of hyaluronidase in synthetic urine as a biomarker for bladder and prostate cancer.

Elevated hyaluronidase levels are found in the urine of bladder and prostate cancer patients. Therefore, HA-ase is regarded as an important biomarker for the detection of these cancers. In this report, we use a FRET based ratiometric sensing approach to detect the level of HA-ase in synthetic urine.