Fabrication of a Nanofilter for a Microdialysis Chip Using Carbon Nanotubes

Abstract

This paper describes the fabrication of cost-effective and pore size-controllable nanofilter using carbon nanotubes (CNTs) for microdialysis system. Studies using microfluidic chips have enabled miniaturization of biochemical techniques and improvement analytical results. However, sample pretreatment such as sample purification or concentration still difficulties chip-level performance. Dialysis is one of frequently used sample pretreatment in conventional biochemical analysis. A CNT nanofilter can help to perform dialysis in nano-scale. CNTs are actively studied because they have extraordinary mechanical, electrical, and structural properties. The pore size of a CNT nanofilter can be controlled at a few nano meter resolution by varying CNT density and length in a CNT nanofilter. CNTs are entangled each other by amide bonding that is catalyzed by 1-Ethyl-3- (3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The chemically treated CNTs are shaped to form a nanofilter using a PDMS film mold and vacuum filtering. Vacuum filtering helps that a CNT nanofilter is homogeneous. Fabricated CNT nanofilter is integrated in PDMS microfluidic chip that is fabricated a standard photolithography. A CNT nanofilter can perform microdialysis that extracts biosamples from a complex biosample solution based on the molecules`s size.