Development of high performance photoelastic modulator and its application to measurements of solid-state circular dichroism

高性能光弹调制器的研制及其在固态圆二色性测量中的应用

基本信息

批准号：
15550011
负责人：
MAEDA Shiro
金额：
$ 1.6万
依托单位：
University of Fukui
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

(1)Improvement of photoelastic modulator (PEM) driverPEM driver, which is optimized to have highest driving efficiency by means of phase-locked loop technique, was improved to have a wide range of driving frequency.(2)Development of thin PEM headsNovel thin PEM heads were made to minimize residual birefringence in the optical element of PEM head which results in artifact signals in solid-state CD measurements. The thickness of the conventional PEM head had been 6.4 mm from the birth of Schnattery type PEM. The thicknesses of novel PEM heads are 2, 3, and 4 mm. The values of R in the electrical equivalent circuit of PEM head are quite low compared with conventional ones.(3)In situ measurement of CD of DNA adsorbing onto a solid surfaceThe adsorption process of DNA dissolved in aqueous solutions onto the surface of polyethyleneimine (PEI) has been examined by the observation of in situ CD, including time-resolved measurements, to elucidate the conformation of DNA at the liquid/solid interface. The adsorption process can be characterized by two stages that are characterized in terms of CD. In the first stage, time (t) <700s, a slight change in the time-resolved CD spectra of DNA is observed, whereas in the second stage, t>700s, where no further adsorption occurs, a change in the induced CD as well as in the CD of DNA is observed.(4)Structural investigation of Poly(ε-lysine) (PL)by solid state-CD measurements.The conformation of microbial PL was estimated by means of solid-state CD measurements. The CD measurements were done by using artifact-free technique for the PL films obtained by casting the aqueous solution with various pH onto a glass plate.

(1)光弹性调制器(PEM)驱动器的改进PEM驱动器通过锁相环技术优化为具有最高的驱动效率，改进为具有较宽的驱动频率范围。(2)薄型PEM头的开发新型薄型PEM 头的制造是为了最大限度地减少 PEM 头光学元件中的残余双折射，这种残余双折射会导致固态 CD 测量中的伪影信号。传统 PEM 头的厚度自诞生以来一直为 6.4 毫米。 Schnattery型PEM头的厚度为2、3、4mm，与传统的PEM头相比，其等效电路中的R值相当低。(3)CD的原位测量。 DNA 吸附到固体表面通过原位 CD 观察（包括时间分辨测量）检查了溶解在水溶液中的 DNA 吸附到聚乙烯亚胺 (PEI) 表面的过程，以阐明 DNA 的构象DNA 在液/固界面的吸附过程可以用 CD 来表征，在第一阶段，时间 (t) <700 秒，DNA 的时间分辨 CD 光谱发生轻微变化。观察到，而在第二阶段，t>700s，没有发生进一步的吸附，观察到诱导的CD以及DNA CD的变化。(4)聚(ε-赖氨酸)(PL)的结构研究经过固态CD测量。通过固态CD测量来估计微生物PL的构象。CD测量是通过使用无伪影技术对通过将具有不同pH的水溶液浇铸到玻璃板上获得的PL膜进行的。。