Thermal lens microscope

Uchiyama, K., Hibara, A., Sato, K., Hisamoto, H., Tokeshi, M., Kitamori, T., An interface chip connection between capillary electrophoresis and thermal lens microscope. Electrophoresis 2003, 24, 179-184. 

Figure 3 MUOs and CFCP. Abbreviation TLM, thermal lens microscope (Tokeshi et al., 2002).

The coexisting metal chelates are decomposed when they make contact at the HCl-m-xylene interface, and the metal ions are dissolved in the HCI solution phase. The decomposed fragment of NN is dissolved in NaOH solution, and the Co-NN chelate is stable in concentrated HCI and NaOH solutions, where it remains. Finally, the target chelates in m-xylene are detected by a thermal lens microscope downstream, where the Co(II) in aqueous solutions was successfully determined. The limit of detection (2analysis time in this system is only 50 s versus 6h for conventional devices. Micro chemical processing through use of CFCP has been demonstrated on numerous occasions (Table 1). 

We have developed a novel ultrasensitive detection method, thermal lens microscopy (TLM), for nonfluorescent species [13]. TLM is photothermal spectroscopy under an optical microscope. Our thermal lens microscope (TLM) has a dual-beam configuration excitation and probe beams [13]. The wavelength of the excitation beam is selected to coincide with an absorption band of the target molecule and that of the probe beam is chosen to be where the sample solution (both solvent and solute) has no absorption. For example, in determination of methyl red dye in water, cyclohexane, and n-octanol, a 514-nm emission line of an argon-ion laser and a 633-nm emission line of a helium-neon laser were used as excitation and probe beams, respectively [21], Figure 4 shows the configuration and principle of TLM [13]. The excitation beam was modulated at 1 kHz by an optical chopper. After the beam diameters were expanded, the excitation and probe beams were made coaxial by a dichroic mirror just before they were introduced into an objective lens whose magnification and numerical aper-... 

Figure 4 Operating principles of thermal lens microscope (TLM).

Figure 5 A desktop thermal lens microscope ITLM-10 (Institute of Microchemical Technology, Inc., Japan).

Sorouraddin HM, Hibara A, Kitamori T. Use of a thermal lens microscope in integrated catecholamine determination on a microchip. Fresenius J Chem 2001 371 91-96. 

Zheng J, Odake T, Kitamori T, Sawada T. Miniaturized ultrathin slab gel electrophoresis with thermal lens microscope detection and its application to fast genetic diagnosis. Anal Chem 1999 71 5003-8. 

Tokeshi, M., Uchida, M., Hibara, A., Sawada, T., and Kitamori, T., Determination of subyocto-mole amounts of nonfluorescent molecules using a thermal lens microscope Subsingle molecule determination, Ana/yt/caZ Chemistry, 73, 2112-2116, 2001. 

Kitagawa, R, Tsuneka, T., Akimoto, Y., Sueyoshi, K., Uchiyama, K., Hattori, A., and Otsuka, K., Toward million-fold sensitivity enhancement by sweeping in capillary electrophoresis combined with thermal lens microscopic detection using an interface chip. Journal of Chromatography A, 1106,36 2, 2006. 

Tamaki E et al (2002) Single-cell analysis by a scanning thermal lens microscope with a mica o-chip direct monitoring of cytochrome c distribution during apoptosis process. Anal Chem 74 1560-1564... 

In order to solve these problems, differential interference contrast thermal lens microscope (DIC-TLM) was developed. The principle of DIC-TLM is shown in Fig. 8. The probe beam is separated into two beams and integrated again using a pair of DlC prisms. Contrary, the excitation beam is not separated and induces a local change in refractive index only for the one of the separated probe beams. Thus, phase contrast appeared between the probe beams is detected through an interference. 

Yamanchi M, Mawatari K, Hibara A, Tokeshi M, Kitamori T (2006) Circular-dichroism thermal lens microscope for sensitive chiral analysis on microchip. Anal Chem 78 2646... 

T (2006) UV-excitation thermal lens microscope for non-labeled and ultrasensitive detection of... 

Shimizu H, Mawatari K, Kitamori T (2009) Development of a differential interference contrast thermal lens microscope for sensitive individual nanoparticle detection in liquid. Anal Chem 81 9802... 

Interferon-y Specific antibodies Sandwich immunoassay with capture antibody immobilized on beads, colloidal gold as tracer Thermal lens microscope... 

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