Ultrasensitive detection of nonlabelled bovine serum albumin using photothermal optical phase shift detection with UV excitation
Ultrasensitive detection of nonlabelled bovine serum albumin using photothermal optical phase shift detection with UV excitation
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DOI：
10.1039/d0an00037j
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发表时间：
2020-04-07
期刊：
影响因子：
4.2
通讯作者：
Kitamori, Takehiko
中科院分区：
文献类型：
--
作者：
Shimizu, Hisashi;Takeda, Shigenori;Kitamori, Takehiko
超灵敏检测未标记的牛血清白蛋白进行微/纳流控芯片使用光热光学相移（POPS）检测系统。目前，微流体和纳米流体允许分析各种单细胞，其目标正在从核酸转移到蛋白质。在此之前，我们的团队开发了光热检测技术，用于非荧光分子的灵敏检测。例如，我们开发了一种热透镜显微镜（TLM），其在单分子水平上具有超灵敏度，以及一种适用于小于光波长的纳米通道的POPS检测器。POPS检测器还实现了在纳米通道中的非标记蛋白质的检测，尽管由于背景光减少不足，其检测灵敏度低于微通道中的TLM。为了克服这个问题，我们开发了一种新的POPS检测器，使用中继光学进一步减少背景光。此外，从样品溶液到纳米通道壁的热传递进行了彻底的研究，以实现温度敏感性。使用新的POPS检测器获得的检测限（LOD）为1.0 fL中的30个分子。考虑到该LOD，新的POPS检测器的性能与TLM的性能相当。由于即使在纳米通道或单μ m通道，这不能实现与TLM的POPS检测器的灵敏检测的适用性，POPS检测器和分离技术，采用独特的纳米通道特性的组合将有助于在未来的单细胞蛋白质组学的进步。
Ultrasensitive detection of nonlabelled bovine serum albumin is performed in micro/nanofluidic chips using a photothermal optical phase shift (POPS) detection system. Currently, micro- and nanofluidics allow the analysis of various single cells, and their targets of interest are shifting from nucleic acids to proteins. Previously, our group developed photothermal detection techniques for the sensitive detection of nonfluorescent molecules. For example, we developed a thermal lens microscope (TLM) with ultrahigh sensitivity at the single-molecule level and a POPS detector that is applicable to nanochannels smaller than the wavelength of light. The POPS detector also realized the detection of nonlabelled proteins in nanochannels, although its detection sensitivity is less than that of the TLM in microchannels due to insufficient background light reduction. To overcome this problem, we developed a new POPS detector using relay optics for further reduction of the background light. In addition, heat transfer from the sample solution to the nanochannel wall was thoroughly investigated to achieve ultrahigh sensitivity. The limit of detection (LOD) obtained with the new POPS detector is 30 molecules in 1.0 fL. Considering this LOD, the performance of the new POPS detector is comparable with that of the TLM. Owing to the applicability of the POPS detector for sensitive detection even in nanochannels or single-mu m channels, which cannot be realized with the TLM, combinations of the POPS detector and separation techniques employing unique nanochannel properties will contribute to advances in single-cell proteomics in the future.