title: Developing a non-fouling hybrid microfluidic device for applications in circulating tumour cell detections.
abstract: Non-specific cell adsorption is a challenge in sensitive detections using microfluidic systems, such as detecting circulating tumour cells from blood samples. In this report, we present a new strategy to study the combined effects of surface hydrophilicity/hydrophobicity, electric charges and roughness on surface non-fouling properties of a PDMS/SU-8 microfluidic system. To achieve this, microchannel surfaces were modified by poly(amidoamine) generation 4 and generation 7, dendrimers that rendered surfaces negatively and positively charged at pH 7.4, respectively. Water contact angle, atomic force microscopy (AFM) and microscopy were used to characterize and confirm surface modifications, and the non-fouling performance of the resulting surfaces was tested using both live and dead CCRM-CEM cancer cells. Our results show that for live cells, electric charges of a surface is the most important factor affecting the non-fouling features of the surface in microfluidic systems; in contrast, for dead cells, surface hydrophilicity is the most important factor affecting surface non-fouling properties. However, surface roughness does not seem to be as important for both live and dead cells under the experimental conditions used in this study. These results also highlight the importance of different considerations when designing a lab-on-a-chip microfluidic system for high sensitivity biosensing and detection applications.
authors.affiliation: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
authors.forename: Yubo
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Hainan Institute of Science and Technology, 571126 Haikou, China.
authors.forename: Xiuying
authors.initials: X
authors.lastname: Yang
authors.affiliation: Hainan Institute of Science and Technology, 571126 Haikou, China. Electronic address: zhangjc1@mail.buct.edu.cn.
authors.forename: Jingchang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada; Ottawa-Carleton Institute of Biomedical Engineering, Ottawa, Ontario K1N 6N5, Canada. Electronic address: xcao@eng.uottawa.ca.
authors.forename: Xudong
authors.initials: X
authors.lastname: Cao
mesh_terms: D000327:Adsorption; D050091:Dendrimers / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D056656:Lab-On-A-Chip Devices; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D018625:Microscopy, Atomic Force; D009369:Neoplasms / Q000175:diagnosis; D009360:Neoplastic Cells, Circulating; D009757:Nylons / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D011073:Polyamines / Q000737:chemistry; D013499:Surface Properties
chemical_list: D050091:Dendrimers; D004129:Dimethylpolysiloxanes; D009757:Nylons; C531249:Poly(amidoamine); D011073:Polyamines; C085707:poly(dimethylsiloxane)-polyamide copolymer; D010100:Oxygen
keywords: CTC; Dendrimer; Detection; Microfluidic channels; Non-fouling