Fluorescence quantum yield determination by pulsed source single photon counting

Simple and Accurate Quantification of Quantum Yield at the Single-Molecule/Particle Level

“…For any photoluminescent species, quantum yield represents one of most fundamental and important properties . Quantum yield is usually used to characterize the photoluminescent species, evaluate the extent of internal conversion and intersystem crossing, and determine the purity of materials. , In theory, the quantum yield ( Q ) of a photoluminescent molecule is defined as the efficiency of the conversion of absorbed photons ( N abs ) to emitted photons ( N em ): − Q = N em N abs …”

Analysis of multicomponent fluorescent mixtures through temporal resolution

“…Instrumentation. The instrumentation of the time-correlated single photon technique used in this laboratory has been described elsewhere (12,14,21). Cline Love and Shaver have evaluated the reiterative convolution program utilized in this work (10,22).…”

“…Prepared mixtures of known composition were irradiated in the nanosecond TCSP fluorometer using the 337-nm excitation of a nitrogen flash lamp. Emission filters were used (Corning 0-52) which transmitted the spectra of both components equally so that the count rate, R, is truly proportional to the fluorescence intensity, e^c (21). The total counts taken were approximately 10000 and blanks were subtracted when necessary.…”

“…A cc Rt (3) The count rate, R, is proportional to the fluorescence intensity which is, in turn, proportional to e0c (21). Therefore, the area under the decay curve is related to these molecular constants and the concentration as shown in Equation 4.…”

Quantitative Measurements of the pH-Sensitive Quantum Yield of Fluorophores in Mesoporous Silica Thin Films Using a Drexhage-Type Experiment

“…In a typically performed relative measurement, the absorption and emission of a luminophore with unknown Φ PL are compared to those of a standard with known Φ PL . Alternatively, Φ PL can be obtained absolutely using a calibrated integrating sphere setup. − Other alternatives for transparent solutions are photothermal methods like photoacoustic spectroscopy and thermal lensing that can measure the dissipated heat. , All these methods are used for ensemble studies because they need a relatively high concentrations or number of luminophores to obtain a detectable signal. ,,− Hence, concentration-dependent effects like reabsorption and dye–dye interaction resulting in fluorescence quenching can affect Φ PL if not properly considered by measurements of concentration series or variations in sample volume. This may hamper the studies of the possible concentration dependences of Φ PL of nanocrystalline emitters with coordinatively bound surface ligands, which are often prone to ligand desorption-induced fluorescence quenching .…”