Arakawa E T, Lavrik N V, Rajic S, Datskos P G
Oak Ridge National Laboratory, 1 Bear Creek Rd. Oak Ridge, TN 37831-8039, USA.
Ultramicroscopy. 2003 Oct-Nov;97(1-4):459-65. doi: 10.1016/S0304-3991(03)00074-3.
We report on the application of infrared (IR) microcalorimetric spectroscopy ( micro -CalSpec) to the identification and detection of trace amounts of biological species. Our approach combines principles of photothermal IR spectroscopy with ultrasensitive microcantilever (MC) thermal detectors. We have obtained photothermal IR spectra for DNA and RNA bases and for Bacillus Cereus (an anthrax simulant) in the wavelength range of 2.5-14.5 micro m (4000-690 cm(-1)). The measurements are accomplished by absorbing biological materials directly on a MC thermal detector. The main advantage of the developed micro -CalSpec is its unprecedented sensitivity as compared to any of the previously explored IR techniques, including FTIR and photothermal FTIR methods. Our results demonstrate that <10(-9)g of a biological sample is sufficient to obtain its characteristic micro -CalSpec spectrum that contains information-rich chemical (vibrational) signatures. This opens up a new opportunity to create inexpensive high-throughput analytical systems for biochemical detection.
我们报告了红外（IR）微量量热光谱法（Micro - CalSpec）在痕量生物物种识别与检测中的应用。我们的方法将光热红外光谱原理与超灵敏微悬臂梁（MC）热探测器相结合。我们已在2.5 - 14.5微米（4000 - 690厘米⁻¹）波长范围内获得了DNA和RNA碱基以及蜡样芽孢杆菌（一种炭疽模拟物）的光热红外光谱。测量是通过将生物材料直接吸附在MC热探测器上完成的。与包括傅里叶变换红外光谱（FTIR）和光热傅里叶变换红外光谱方法在内的任何先前探索的红外技术相比，所开发的Micro - CalSpec的主要优势在于其前所未有的灵敏度。我们的结果表明，<10⁻⁹克的生物样品就足以获得其特征性的Micro - CalSpec光谱，该光谱包含信息丰富的化学（振动）特征。这为创建用于生化检测的廉价高通量分析系统开辟了新机遇。
