2872-52-8Relevant articles and documents
Photonic crystal fibre as an optofluidic reactor for the measurement of photochemical kinetics with sub-picomole sensitivity
Williams, Gareth O. S.,Chen, Jocelyn S. Y.,Euser, Tijmen G.,Russell, Philip St.J.,Jones, Anita C.
, p. 3356 - 3361 (2012)
Photonic crystal fibre constitutes an optofluidic system in which light can be efficiently coupled into a solution-phase sample, contained within the hollow core of the fibre, over long path-lengths. This provides an ideal arrangement for the highly sensitive monitoring of photochemical reactions by absorption spectroscopy. We report here the use of UV/vis spectroscopy to measure the kinetics of the photochemical and thermal cis-trans isomerisation of sub-picomole samples of two azo dyes within the 19-μm diameter core of a photonic crystal fibre, over a path length of 30 cm. Photoisomerisation quantum yields are the first reported for "push-pull" azobenzenes in solution at room temperature; such measurements are challenging because of the fast thermal isomerisation process. Rate constants obtained for thermal isomerisation are in excellent agreement with those established previously in conventional cuvette-based measurements. The high sensitivity afforded by this intra-fibre method enables measurements in solvents in which the dyes are too insoluble to permit conventional cuvette-based measurements. The results presented demonstrate the potential of photonic crystal fibres as optofluidic elements in lab-on-a-chip devices for photochemical applications. This journal is
Six-branched chromophores with isolation groups: Synthesis and enhanced optical nonlinearity
Lin, Wenxin,Cui, Yuanjing,Gao, Junkuo,Yu, Jiancan,Liang, Ting,Qian, Guodong
, p. 9202 - 9208 (2012)
Three new six-branched chromophores with different isolation groups were designed and synthesized by incorporating azo chromophores onto phenyl glycerol ester via an esterification reaction. The chemical structures were confirmed by 1H NMR, 13C NMR, FT-IR spectroscopy, mass spectrometry, element analysis and UV-visible absorption spectra. The six-branched dendritic chromophores can form thin films directly without adding any polymer matrix and show a quite high chromophore loading density. After electric poling, the nonlinear optical coefficients (d33) of the dendrimer films were determined to be around 113, 142 and 136 pm V-1, which are almost 3 times the maximum d33 value of the azo-chromophore doped polymer films. The further improvement in optical nonlinearity was successfully realized by mixing the six-branched chromophores containing different isolation groups.
A simple FRET-based modular design for diagnostic probes
Redy, Orit,Kisin-Finfer, Einat,Sella, Eran,Shabat, Doron
scheme or table, p. 710 - 715 (2012/02/05)
In recent years, there has been a massive effort to develop molecular probes with optical modes of action. Probes generally produce detectable signals based on changes in fluorescence properties. Here, we demonstrate the potential of self-immolative molecular adaptors as a platform for Turn-On probes based on the FRET technique. The probe is equipped with identical fluorophore pairs or a fluorophore/quencher FRET pair and a triggering substrate. Upon reaction of the analyte of interest with the triggering substrate, the self-immolative adaptor spontaneously releases the two dye molecules to break off the FRET effect. As a result, a new measurable fluorescent signal is generated. The fluorescence obtained can be used to quantify the analyte. The modular structure of the probe design will allow the preparation of various chemical probes based on the FRET activation technique.
