RESUMEN
In this study, we report a facile one-pot chemical etching approach to simply and rapidly prepare gold nanoclusters capped with luminol (Lum-AuNCs) in an alkaline aqueous solution at room temperature. A series of characterization studies have been carried out to explore the morphology, the optical properties and chemical components of Lum-AuNCs. The average diameter of Lum-AuNCs is 1.8 ± 0.3 nm, exhibiting fluorescence near 510 nm upon excitation at 420 nm with a quantum yield of 14.29% and an average fluorescence lifetime of 9.47 ns. On the basis of the ligand-induced etching of glutathione (GSH) to the intermediate (luminol capped gold nanoparticles, abbreviated as Lum-AuNPs), a novel and simple method for the fluorescence determination of GSH has been established. The method displays a good linear response in the range of 0.05-300 µM toward GSH with a limit of detection of 35 nM. This detection strategy with high sensitivity and selectivity facilitates its practical application for the detection of GSH levels in cell extracts. The in vitro cell results illustrate that Lum-AuNCs have good cytocompatibility and can be used to readily differentiate normal cells and tumor cells.
Asunto(s)
Colorantes Fluorescentes/química , Glutatión/análisis , Luminol/química , Nanopartículas del Metal/química , Línea Celular Tumoral , Colorantes Fluorescentes/efectos de la radiación , Colorantes Fluorescentes/toxicidad , Oro/química , Oro/efectos de la radiación , Oro/toxicidad , Humanos , Ligandos , Luz , Límite de Detección , Luminol/efectos de la radiación , Luminol/toxicidad , Nanopartículas del Metal/efectos de la radiación , Nanopartículas del Metal/toxicidad , Microscopía Confocal , Microscopía FluorescenteRESUMEN
Direct observation of cavitation fields using photography, sonoluminescence and luminol "mapping" is reported for a 23 kHz horn sonicator and a 515 kHz plate transducer system. The effect of sound intensity and added surfactant on the cavitation fields is described. The observations support previously reported results suggesting significant differences in the cavitation fields between the two sonication systems.
Asunto(s)
Gases/química , Gases/efectos de la radiación , Mediciones Luminiscentes/métodos , Luminol/química , Luminol/efectos de la radiación , Fotograbar/métodos , Sonicación/métodos , Ultrasonografía/métodos , Ensayo de Materiales/métodosRESUMEN
The chemiluminescent oxidation of luminol by hydrogen peroxide in the presence of hemin is revisited in an UV-C cross-linked PVP hydrogel. Chemiluminescence properties such as initial light intensity (I(0)), area of emission (S) and observed rate constants (k(obs)) are studied, varying the concentration of all reactants using a multivariate factorial approach.
Asunto(s)
Hemina/química , Hidrogeles/síntesis química , Luminiscencia , Luminol/química , Povidona/química , Reactivos de Enlaces Cruzados/química , Análisis Factorial , Hemina/efectos de la radiación , Hidrogeles/química , Peróxido de Hidrógeno/química , Concentración de Iones de Hidrógeno , Cinética , Luminol/efectos de la radiación , Estructura Molecular , Oxidación-Reducción , Povidona/efectos de la radiación , Rayos UltravioletaRESUMEN
The chemiluminescence of luminol, after 1 and 2h in vitro exposure of human serum to 50 Hz electric fields of different intensities, decreases as compared to the controls. This indicates a field-induced decrease in the concentration of the free radicals. The report is limited to the key kinetic and field data, inviting independent kinetic analysis of the data in terms of reaction moments or reaction susceptibilities for the various normal modes indicated by the data.
Asunto(s)
Campos Electromagnéticos , Luminiscencia , Luminol/química , Luminol/efectos de la radiación , Suero/química , Suero/efectos de la radiación , Humanos , Cinética , Factores de TiempoRESUMEN
Thermoluminescent dosimetry has been the industry standard for ionizing radiation dosimetry because it is inexpensive, sensitive, and accurate. No such system exists for radio frequency radiation. This paper describes the state of the art of efforts toward developing such a system. Thermochemiluminescent (TCL) dosimetry, first reported in 1991, is a first step toward achieving this goal. However, it has had problems in the production of TCL materials and in conversion of the luminescent signal into specific absorption rate (SAR). The former problem has been solved by the development of a genetically engineered Escherichia coli bacterium (JM 109/plC20RNR1.1), described herein, that produces the TCL material in a fermentation process. The latter problem stems from the difficulty in determining the structure of the currently best TCL material diazoluminomelanin. A theoretical approach for the solution of this problem has been achieved by combining equations for delayed fluorescence, temperature determination by TCL, and the free energy equation for equilibrium reactions. It has led to an explanation for the stable display of steady-state energy disposition, illustrated by TCL, in phantoms without the expected disruption by thermal conduction or convection, at frequencies ranging from 2.06 GHz to 35 GHz.
Asunto(s)
Ondas de Radio , Dosimetría Termoluminiscente/métodos , Absorción , Animales , Biopolímeros/química , Biopolímeros/efectos de la radiación , Fenómenos Químicos , Química Física , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentación , Fluorescencia , Ingeniería Genética , Mediciones Luminiscentes , Luminol/análogos & derivados , Luminol/química , Luminol/efectos de la radiación , Melaninas/química , Melaninas/efectos de la radiación , Fantasmas de Imagen , Dosis de Radiación , Ratas , Temperatura , Conductividad TérmicaRESUMEN
Intense flashes of light were observed in sodium bicarbonate and hydrogen peroxide solutions when they were exposed to pulsed microwave radiation, and the response was greatly enhanced by a microwave-absorbing, biosynthesized polymer, diazoluminomelanin. A FPS-7B radar transmitter, operating at 1.25 GHz provided pulses of 5.73 +/- 0.09 micros in duration at 10.00 +/- 0.03 pulses/s with 2.07 +/- 0.08 MW forward power (mean +/- standard deviation), induced the effect but only when the appropriate chemical interaction was present. This phenomenon involves acoustic wave generation, bubble formation, pulsed luminescence, ionized gas ejection, and electrical discharge. The use of pulsed microwave radiation to generate highly focused energy deposition opens up the possibility of a variety of biomedical applications, including targeting killing of microbes or eukaryotic cells. The full range of microwave intensities and frequencies that induce these effects has yet to be explored and, therefore, the health and safety implications of generating the phenomena in living tissues remain an open question.
Asunto(s)
Biopolímeros/efectos de la radiación , Luminol/análogos & derivados , Melaninas/efectos de la radiación , Microondas , Absorción , Acústica , Aire , Biopolímeros/química , Electricidad , Gases/química , Gases/efectos de la radiación , Humanos , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/efectos de la radiación , Luz , Mediciones Luminiscentes , Luminol/química , Luminol/efectos de la radiación , Melaninas/química , Microondas/clasificación , Microondas/uso terapéutico , Radar , Bicarbonato de Sodio/química , Bicarbonato de Sodio/efectos de la radiación , Sonido , Grabación de Cinta de VideoRESUMEN
Perfusate, blood plasma and tissue homogenate were investigated by H2O2-stimulated chemiluminescence (CL) and photochemiluminescence (PCL) during experimental liver and kidney transplantation. The canine kidneys were perfused prior to reimplantation for 68 h at 4 degrees C. The increase of the H2O2 CL of the perfusate correlated positively with the LDH activity. After ischemic load of the liver, the antioxidative capacity (AC) of the tissue as determined by PCL decreases. After transplantation of the stored liver (1 h, 4 degrees C) an increased AC is observed in peripheral blood. This increase is lower after addition of ascorbate to the preservation solution. The results allow to conclude that both methods are suitable for the characterization of the organ status after hypoxic injury during conservation.