Investigations on Nanoparticle−Chromophore and Interchromophore Interactions in Pyrene-Capped Gold Nanoparticles
摘要:
Three pyrene alkanethiol derivatives (P1, P2, and P3) possessing flexible alkyl groups of different lengths were attached to nanoparticles of gold (similar to2-3 nm in size) along with dodecanethiol (Au-P1, Au-P2, and Au-P3). The photophysical properties of these systems were investigated as a function of (i) distance of chromophore from gold core, (ii) concentration of pyrene on gold surface, and (iii) solvent polarity. The structured absorption bands of the pyrene chromophore were significantly perturbed near the surface of gold nanoparticles (Au-P1), indicating a strong ground state interaction between the plasmon electrons of Au nanoparticles and thepi-electron cloud of the chromophore. Such effects were not observed in Au-P2 and Au-P3 systems, in which the linker groups are long enough to prevent any ground state interactions. A gradual increase in the peak intensity ratio of band III/I of the normal fluorescence of pyrene chromophore was found with an increase in length of the spacer group. These results indicate that the local environment close to the surface of the An nanoparticle is more polar compared to the bulk medium. Interchromophoric interactions are limited in the Au-P1 system due to the restriction imposed by the curvature of spherical gold nanoparticle whereas the flexible alkyl chain tethering pyrene in Au-P2/Au-P3 allows free interaction between chromophores. Steady state and time-resolved emission studies indicate that the normal fluorescence and intermolecular excimer formation are the main deactivation channels of the singlet excited state of pyrene linked to An nanoparticles, in nonpolar solvents. In contrast, the competitive electron transfer to the gold nanocore dominates in polar solvents.
Liquid-Phase Synthesis of N-Functionalized Azanucleoside-Incorporated Oligonucleotides and Development of Anodic C(sp3)–H Acetoxylation Reaction for Direct Preparation of Azaribose
functionalized oligonucleotides. A synthetic route to azaribose, as a precursor of aza-ODNs, was also reinvestigated to realize more efficient production. Electrochemical N-α-acetoxylation in 0.1 M lithium perchlorate/nitromethane/50 mM AcOH medium was found to be a suitable medium for this route. These results represent a newefficient synthetic route to aza-ODNs.
我们报告了芘缀合的氮杂核苷结合寡脱氧核苷酸(氮杂-ODN)的合成。烷基链可溶性载体(ACSS)液相合成和电化学 C-H 活化相结合,实现了对氮杂-ODN 的有效获取,而无需过量的试剂或溶剂。还研究了芘共轭氮杂-ODN 的荧光特性。得到的荧光光谱表明氮原子位置的改变适合于人工功能化寡核苷酸的制备。氮杂核糖的合成路线,作为氮杂-ODNs的前体,也被重新研究以实现更有效的生产。发现在 0.1 M 高氯酸锂/硝基甲烷/50 mM AcOH 介质中的电化学 N-α-乙酰氧基化是该路线的合适介质。
Oxygen sensors based on hard-soft acid-base relationships
申请人:Honeywell Romania S.R.L.
公开号:EP2610609A1
公开(公告)日:2013-07-03
A fluorescence quenching oxygen sensor (100) comprises a support (102) having coated thereon;
a compound having hard or soft acid groups (104); and
one or more pyrene compounds (106) represented by
Y-R-Pyrene (I)
attached to the compound having hard or soft basic groups;
wherein Y is a hard or soft basic group and R is an aliphatic linking group having 1 to 19 carbon atoms. The sensor can be used to prepare a fluorescence quenching oxygen detector.
Oxygen fluorescence quenching sensor, detector comprising the sensor, and method for producing the sensor
申请人:Honeywell Romania S.R.L.
公开号:EP2610609B1
公开(公告)日:2018-10-10
OXYGEN SENSORS BASED ON HARD-SOFT ACID-BASE RELATIONSHIPS
申请人:Serban Bogdan Catalin
公开号:US20130171027A1
公开(公告)日:2013-07-04
A fluorescence quenching oxygen sensor (
100
) comprises a support (
102
) having coated thereon;
a compound having hard or soft acid groups (
104
); and
one or more pyrene compounds (
106
) represented by
Y—R-Pyrene (I)
attached to the compound having hard or soft basic groups;
wherein Y is a hard or soft basic group and R is an aliphatic linking group having 1 to 19 carbon atoms. The sensor can be used to prepare a fluorescence quenching oxygen detector.