Nanoparticle concentration techniques have a strong influence on biomedical and clinical applications. Single cell analysis techniques have a strong influence on biomedical and clinical applications. Pre-concentration of the sample is the main factor for application performance. General nanoparticle concentration techniques such as centrifugation and lyophilization have some limitations, such as aggregation or sample damage, and are therefore not suitable to control the small amount of sample for biological application. On the other hand, optoelectrofluidic technology showed the possibility to focus nanoparticles in a static condition by AC electroosmosis, but all observations were performed using image analysis and thus sample acquirement was not possible. In this thesis, a continuous-flow optoelectrofluidic chip was introduced. Optoelectrofluidic focusing effect in the continuous-flow device was investigated under various conditions, including voltage, flow rate, frequency, particle size, and electrode shape. Three-outlet channel for collecting the concentrated sample was also designed and fabricated. The device was demonstrated with polystyrene nanoparticles and the concentrated sample was successfully acquired and analyzed by dynamic light scattering. These phenomena can be utilized as a novel method for concentrating biological samples in the nanometer range.
나노농축기술은 단일세포분석등 다양한 의약 및 생명 연구에 필수적이다. 소량의 분석시료를 다뤄야 하기 때문에 나노입자를 농축시키는 과정은 매우 중요하다. 일반적인 원심분리, 동결건조, 증발 등의 농축기술은 바이오분야에서 사용되는 소량 샘플에 적합하지 않으며 샘플에 손상을 줄 수 있다. 이 논문에서는 광전자유체방식을 이용하여 소량의 샘플을 농축시킬 수 있는 새로운 장비를 소개한다. 광전도성칩으로 이루어진 장비의 밑면은 빛이 조사됨에 따라 가상전극을 형성하며, 나노입자들은 가상전극에 의한 교류 전기침투 현상에 의해 칩의 가운데로 집속한다. 집속된 입자들은 액체의 연속적인 흐름에 의해 수득이 가능하다. 수득된 나노입자의 농도는 동적광산란장비를 이용하여 분석하였다. 이 장비를 통해 전압, 유속, 주파수, 입자의 크기와 초기 농도에 따른 농축 정도를 확인할 수 있었다. 이를 통해 소량의 나노입자 샘플을 제어가능하게 농축할 수 있다.
