Farmehini Vahid, Rohani Ali, Su Yi-Hsuan, Swami Nathan S
Department of Electrical & Computer Engineering, University of Virginia, Charlottesville, VA 22904, USA.
Lab Chip. 2014 Nov 7;14(21):4183-7. doi: 10.1039/c4lc00801d.
Insulator-based dielectrophoresis enables contact-less separation and analysis of biosystems, but it is unable to operate effectively in the MHz frequency range, which is necessary for the manipulation of biological cells based on the characteristic electrophysiology of their cytoplasm or biomolecular preconcentration based on their unique conformation. To address the steep drop in output power and the rise of signal distortions within conventional amplifiers at MHz frequencies due to slew rate limitations, we present the design principles for a wideband amplifier. This is validated by demonstrating the absence of harmonic distortions and parasitic DC within the amplifier output up to 15 MHz, thereby enabling analysis of cytoplasmic alterations on oocysts of Cryptosporidium parvum, due to constant force dispersion in the MHz range.
基于绝缘体的介电电泳能够实现生物系统的非接触式分离和分析,但它无法在兆赫兹频率范围内有效运行,而这一频率范围对于基于生物细胞质的特征电生理学来操纵生物细胞或基于其独特构象进行生物分子预浓缩是必不可少的。为了解决由于转换速率限制导致的传统放大器在兆赫兹频率下输出功率急剧下降和信号失真增加的问题,我们提出了一种宽带放大器的设计原理。通过证明在高达15兆赫兹的放大器输出中不存在谐波失真和寄生直流,从而验证了该原理,这使得能够在兆赫兹范围内由于恒定力分散而对微小隐孢子虫卵囊的细胞质变化进行分析。