prediction using pure standards is expected to be biased whenever the slope of the calibration is affected by the presence of sample matrix. moreover, in the presence of unknown spectral interferents, first-order algorithms like partial least squares cannot be used. in this study, a method for determination of carvedilol (car) in tablet and urine samples is proposed by excitation-emission fluor...

A laboratory class is described to introduce the biochemistry major students to the basic concepts and various applications of fluorescence spectroscopy. Through simple and inexpensive experiments the students learn how to record excitation and emission spectra and measure intrinsic protein fluorescence and its quenching to elucidate the local tryptophan environment. Free tryptophan, ovalbumin,...

There is no satisfactory mechanism to detect premalignant lesions in the upper aero-digestive tract. Fluorescence spectroscopy has potential to bridge the gap between clinical examination and invasive biopsy; however, optimal excitation wavelengths have not yet been determined. The goals of this study were to determine optimal excitation-emission wavelength combinations to discriminate normal a...

conclusions the expression of recombinant calprotectin, as an effective protein, can help in diagnosis or treatment of inflammatory and cancer processes in the future. furthermore, ca2+ induced a partial change in secondary and tertiary structure of calprotectin subunits and this change is probably necessary for protein dimerization. results interaction of s100a8 and s100a9 in the presence of c...

Organic donor-bridge-acceptor dyads consisting of a triphenyldiamine donor that was linked to a perylenebisimide acceptor by a flexible nonconjugated bridge have been investigated by complementary spectroscopic techniques as a function of the length and the polarity of the linker. Time-resolved fluorescence spectroscopy revealed a quenching of the donor emission accompanied by a corresponding r...

Changes in fluorescence emission of the serum from patients with various cancers are characterized. The measurement of fluorescence emission of serum in the UVvisible range allows by estimation of NAD(P)H levels to monitor the alterations in energy metabolism, resulting from changes in the level of coenzymes in serum associated with neoplastic diseases. Introduction Over the past years, f luore...

Fluorescent organic nanoparticles based on aggregation induced emission dyes are fabricated through a ring-opening reaction using polylysine as the linker. The fluorescent organic nanoparticles obtained are characterized by a series of techniques including UV-vis absorption spectroscopy, fluorescence spectroscopy, Fourier Transform infrared spectroscopy, and transmission electron microscopy. A ...

Fluorescence spectroscopy provides potential contrast enhancement for near-infrared tissue imaging and physiologically correlated spectroscopy. We present a fluorescence photon migration model and test its quantitative predictive capabilities with a frequency-domain measurement that involves a homogeneous multiple-scattering tissue phantom (with optical properties similar to those of tissue in ...