Sikanen Tiina, Heikkilä Liisa, Tuomikoski Santeri, Ketola Raimo A, Kostiainen Risto, Franssila Sami, Kotiaho Tapio
Laboratory of Analytical Chemistry, Department of Chemistry, Division of Pharmaceutical Chemistry, Faculty of Pharmacy, and Drug Discovery and Development Technology Center, University of Helsinki, Helsinki, Finland.
Anal Chem. 2007 Aug 15;79(16):6255-63. doi: 10.1021/ac0703956. Epub 2007 Jul 17.
Effective analytical performance of native, all-SU-8 separation microdevices is addressed by comparing their performance to commercial glass microdevices in microchip zone electrophoresis accompanied by fluorescence detection. Surface chemistry and optical properties of SU-8 microdevices are also examined. SU-8 was shown to exhibit repeatable electroosmotic properties in a wide variety of buffers, and SU-8 microchannels were successfully utilized in peptide and protein analyses without any modification of the native polymer surface. Selected, fluorescent labeled, biologically active peptides were baseline resolved with migration time repeatability of 2.3-3.6% and plate numbers of 112,900-179,800 m(-1). Addition of SDS (0.1%) or SU-8 developer (1.0%) to the separation buffer also enabled protein analysis by capillary zone electrophoresis. Plate heights of 2.4-5.9 microm were obtained for fluorescent labeled bovine serum albumin. In addition, detection sensitivity through SU-8 microchannels was similar to that through BoroFloat glass, when fluorescence illumination was provided at visible wavelengths higher than 500 nm. On the whole, the analytical performance of SU-8 microchips was very good and fairly comparable to that of commercial glass chips as well as that of traditional capillary electrophoresis and chromatographic methods. Moreover, lithography-based patterning of SU-8 enables straightforward integration of multiple functions on a single chip and favors fully microfabricated lab-on-a-chip systems.
通过在荧光检测的微芯片区带电泳中将其性能与商用玻璃微器件进行比较，研究了原生全SU-8分离微器件的有效分析性能。还研究了SU-8微器件的表面化学和光学性质。结果表明，SU-8在多种缓冲液中表现出可重复的电渗性质，并且SU-8微通道在未经对原生聚合物表面进行任何修饰的情况下成功用于肽和蛋白质分析。选定的、荧光标记的生物活性肽在基线处得到分离，迁移时间重复性为2.3-3.6%，塔板数为112,900-179,800 m(-1)。向分离缓冲液中添加SDS（0.1%）或SU-8显影剂（1.0%）也能够通过毛细管区带电泳进行蛋白质分析。对于荧光标记的牛血清白蛋白，获得了2.4-5.9微米的塔板高度。此外，当在高于500 nm的可见波长下提供荧光照明时，通过SU-8微通道的检测灵敏度与通过硼硅酸盐玻璃的检测灵敏度相似。总体而言，SU-8微芯片的分析性能非常好，与商用玻璃芯片以及传统毛细管电泳和色谱方法的性能相当。此外，基于光刻的SU-8图案化能够在单个芯片上直接集成多种功能，并有利于完全微制造的芯片实验室系统。
