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The JY Fluorolog-3-11 provides optimum performance for highly scattering samples such as proteins, Membranes and Solid samples. Both excitation radiation and emitted radiation can be scanned.
C) Relative Fluorescence Quantum Yield: Fluorescence quantum yield is a measurement which will provide the efficiency of fluorescence. The quantum yield value is determined with respect to a standard sample of known quantum yield. D) Fluorescence quenching: The decrease in the fluorescence intensity of a sample in presence of an external species is called quenching. Fluorescence quenching constant can be determined by Stern-Volmer analysis by measuring the emission of the sample in presence of a series of quencher concentrations. G) Synchronous scanning: This method involved simultaneous measurements of excitation and emission wavelength using a constant wavelength interval. The analysis helps to resolve the spectral features of individual components in a mixture of fluorophores. (eg. Petroleum products) H) FRET: Forster resonance energy transfer (FRET) is a phenomenon where the excited state energy of a fluorophore is transferred to another fluorophore through dipole-dipole interaction. In order to show FRET, the emission spectrum of the fluorophore which transfer energy should be overlapping with the absorption spectra of the fluorophore which absorbs the energy. | Description
Steady State Fluorescence Experiments
A) Steady State Fluorescence spectrum: Fluorescence spectrum of a sample consists of collection of emission light in a range of selected wavelength, by exciting the sample at a specific wavelength. The instrument at SAIF can measure the fluorescence, if your sample can emit light in between 200 nm to 800 nm. The spectrum can be measured for powders, liquid and thin films. B) Excitation Spectrum: Excitation spectrum consists of collection of emission from a sample at a specific wavelength, by exciting the sample in a range of wavelengths. Comparison of the excitation spectrum with the absorption spectrum of the sample will enable you to check purity of the sample, and presence of excited states other than locally excited state. The spectrum can be measured for powders, liquid and thin films. E) Solvatochromism: Solvatochromic samples exhibit color change according to the polarity of the medium. If your sample contains electron rich and electron deficient moieties, it is likely that they may exhibit solvatochromic behavior. Solvatochormism studies can be conducted ONLY in solution. F) TICT emission, MLCT/LMCT emission: Twisted intramolecular charge transfer emission (TICT) is a phenomena exhibited by fluorophores which can undergo a twist during the excited state lifetime. Such samples provide extra emission peak as a function of solvent polarity. Metal to ligand charge transfer (MLCT) or Ligand to metal charge transfer (LMCT) measurements can be carried out for metal complexes. TICT, MLCT and LMCT studies can be conducted ONLY in solution. I) 3D Fluorescence Spectrum(Excitation-Emission Matrix): An EEM(Excitation-Emission Matrix) is a 3D scan, resulting in a contour plot of excitation wavelength vs. emission wavelength vs. fluorescence intensity. 3D fluorescence spectrometry is a very promising method for the identification and characterization of the fluorescent substances, and the determination of several components of the complex intermixture. Multidimensional fluorescence techniques, such as EEM and synchronous scanning fluorescence are particularly useful for the analysis of complex mixtures such as crude oils, pharmaceuticals, polycyclic aromatic hydrocarbons, motor oils, and contaminants in water.
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