Microfluidics-Based Microwave Hairpin Resonator Biosensor for Biological Cell Detection and Analysis

• Main Authors: Chia-FengLiu, 劉佳峯
• Other Authors: Ling-Sheng Jang
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/kk8779

博士 === 國立成功大學 === 電機工程學系 === 106 === Cell impedance analysis is one of theme and has been researched in depth. Impedance studies can indicate the pathological status of cells. However, parameters of cells based on average of large populations may be misleading by cellular heterogeneity. In order to get parameters of cells precisely, the technology of small amount of cells analysis was developed. In this work, a microwave hairpin resonator fabricated and integrated with microfluidics was used for the detection of biological cells. The resonant-based biosensors primarily determine the dielectric properties of cells based on the electromagnetic interaction between the resonator and the cells being tested. At microwave frequencies, the ability of the electromagnetic waves to penetrate into cells, contrary to low-frequency situations where the bi-lipidic membrane screens the fields, ensures access to rich information on cells. The biosensor was a microfluidic device constructed from polydimethylsiloxane (PDMS) and negative photoresist (SU-8) using micro-electro-mechanical-system (MEMS) technology to measure and characterize biological cells in a liquid medium. By using only one step of the SU-8 process, the SU-8 layer plays multiple roles: forming the cell trapping structures, defining the patterns for electroplating, and bonding with the PDMS cover plate. A biosensor with a high-Q dielectric resonator allowed the detection of biological cells by measuring the scattering parameter (S-parameter) responses at a resonant frequency of 2.17 GHz. Measurements and analyses of Dulbecco’s modified Eagle’s medium (DMEM) and B16F10 melanoma cells (mus musculus skin melanoma) were then performed to obtain the linear relationship between S11 responses and the number of cells. A model of coupled resonators in terms of capacitances was then used to analyze the effects of DMEM and the cells. Then, the relative dielectric constant of the B16F10 melanoma cell was found to be 35.6. The results demonstrate the potential of hairpin resonator sensors for the analysis of biological cells.