Circular dichroism thermal lens microscope for sensitive chiral analysis on microchip
Circular dichroism thermal lens microscope for sensitive chiral analysis on microchip
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DOI：
10.1021/ac0519920
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发表时间：
2006-04-15
影响因子：
7.4
通讯作者：
Kitamori, T
中科院分区：
文献类型：
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作者：
Yamauchi, M;Mawatari, K;Kitamori, T
为了在微芯片上实现对小体积手性样品的高灵敏度和高选择性检测，研制了一种新型手性检测器-圆二色性热透镜显微镜（CD-TLM）。为了在TLM上实现手性识别，激发光束在1.2kHz的频率下被相位调制，并且产生左旋圆偏振光（LCPL）和右旋圆偏振光（RCPL）。然后，检测LCPL和RCPL之间的差分光吸收，即CD效应，作为热透镜信号强度和相位。作为标准样品，使用光学活性三（乙二胺）钴（III）[Co（en）（3）]I-3+（3）-水溶液进行性能评价。首先，我们通过比较激发光强度调制和相位调制模式下的信号，验证了选择性手征分析的基本原理。此外，我们发现，g-因子，这是显着的确定对映体过量，同意与CD光谱仪获得的值。对映体纯[Co-（en）（3）]I-3+（3）-的检测限（LOD）为6.3 × 10（-5）M（1.9 × 10（-7）绝对值）（对于（-）-Co（en）（3）（3+）），以吸光度单位计的灵敏度比CD分光光度计高250倍以上。最后，我们展示了对映体过量测定的微芯片。（-）Co（en）（3）（3+）的LOD为1.7%（8.5 x 10（-7）绝对值），比CD光谱仪的LOD至少高上级一个数量级。CD-TLM在微芯片上的灵敏手性分析的适用性得到了验证，CD-TLM有望用于基于微芯片的手性合成和分析系统。
A novel chiral detector, a circular-dichroism thermal lens microscope (CD-TLM), was developed to realize sensitive and selective detection of small volume chiral samples on a microchip. To realize chiral recognition on TLM, an excitation beam was phase-modulated at a frequency of 1.2 kHz, and left-circularly polarized light (LCPL) and right-circularly polarized light (RCPL) were generated. Then, the differential light absorption between LCPL and RCPL, which is the CD effect, was detected as thermal lens signal intensity and phase. As a standard sample, optically active tris(ethylenediamine)cobalt(III) [Co(en)(3)]I-3+(3)- aqueous solutions were used for performance evaluations. First, we verified the basic principle for selective chiral analysis by comparing the signals in intensity-modulation and phase-modulation modes of the excitation beam. Also, we found that the g-factor, which is significant for determining enantiomeric excess, agreed well with the value obtained by the CD spectrometer. The limit of detection (LOD) for enantiopure [Co-(en)(3)]I-3+(3)- was 6.3 x 10(-5) M (1.9 X 10(-7) abs) for (-)-Co(en)(3)(3+), and the sensitivity in absorbance units was more than 250 times higher than that in a CD spectrophotometer. Finally, we demonstrated enantiomeric excess determination on a microchip. The LOD was 1.7% (8.5 x 10(-7) abs) for (-)Co(en)(3)(3+) and at least one order superior to the LOD of a CD spectrometer. The applicability of CD-TLM for sensitive chiral analysis on a microchip was verified, and CD-TLM is expected to be promising for microchip-based chiral synthesis and analysis systems.