PHOTOTHERMAL SPECTROSCOPY WITH FEMTOJOULE SENSITIVITY USING A MICROMECHANICAL DEVICE
PHOTOTHERMAL SPECTROSCOPY WITH FEMTOJOULE SENSITIVITY USING A MICROMECHANICAL DEVICE
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DOI：
10.1038/372079a0
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发表时间：
1994-11-03
期刊：
影响因子：
64.8
通讯作者：
GIMZEWSKI, JK
中科院分区：
文献类型：
--
作者：
BARNES, JR;STEPHENSON, RJ;GIMZEWSKI, JK
当一种物质吸收一个光子时，一部分能量可能转化为热量。作为波长的函数的光热加热的测量可以提供材料的吸收光谱。我们最近（1，2）开发了一种微机械传感器，能够检测皮焦耳（10（-12）J）量级的热变化。该仪器包括一个双层悬臂的微米尺寸的弯曲响应加热。在这里，我们表明，该设备可以用于光热光谱与100 pW的功率灵敏度-两个数量级优于传统的光热偏转光谱的灵敏度（3）。传感器的小尺寸允许研究皮克数量的材料，开辟了对单个细胞和细菌进行光谱研究的可能性。传感器基于硅技术，应与微电子电路兼容。
WHEN a material absorbs a photon, a fraction of the energy may be transformed into heat. A measurement of photothermal heating as a function of wavelength can provide an absorption spectrum of the material. We have recently(1,2) developed a micromechanical sensor capable of detecting heat changes of the order of picojoules (10(-12) J). The instrument incorporates a bilayer cantilever of micrometre dimensions which bends in response to heating. Here we show that this device can be used for photothermal spectroscopy with a power sensitivity of 100 pW-two orders of magnitude better than the sensitivity of conventional photothermal deflection spectroscopy(3). The small size of the sensor allows picogram quantities of material to be studied, opening up the possibility of spectroscopic studies on individual cells and bacteria. Being based on silicon technology, the sensor should be compatible with microelectronic circuitry.