Fabrication Of Multiwalled Carbon Nanotube/polymer Thin Film And Its Applications In Biological Detection

Microfluidics has been rapidly developed into a powerful approach capable ofintegrating multiple functions for micrototal analysis (mTAS), because they can provideprecise fluid control, minimum sample and reagent consumption, device miniaturization,and large-scale integration. Polydimethylsiloxane (PDMS) is one of the most commonmaterials used in microfluidic chips because of good biocompatibility, low cost, easysealing and fabrication. However, hydrophobic surface and adsorption of biomoleculehinder its application and development. In contrast, Carbon nanotubes (CNT) are someof the most promising materials for the design of functional thin films, due to theirunique physical properties, including high electrical conductivity, superior chemical andmechanical stability, and large surface area. Moreover, nanotopography exhibited byCNT layers plays a critical role in modifying cell development and proliferation, as wellas the strength of adhesion to substrates. In this paper, we designed and developed anew type of multiwalled carbon nanotube/polymer thin flim as a modified material forPDMS. Then MWCNT/PAH thin film based microfluidic chips were fabricated andcultured tumor cells on the chip.MWCNT/PAH thin film was fabricated by layer by layer assembly, andcharacterized by SEM, AFM, NanoIdentation, contact angle measurement, and thencultured Hela cells on the film to test its biocompatibility. It was shown that the surfacemorphology and internal structure of MWCNT/PAH thin film was physicalinterconnected network structure with randomly distributed individual MWCNTs.Roughness increased with the increasing of MWCNT/PAH thin film layers, but notsignificantly. Contact angles decreased with the increasing of the film layers, but theydid not change obviously if there were more than80layers. The flexibility ofMWCNT/PAH thin film was enough to support the experiments. The density of Cellson MWCNT/PAH thin films was higher than that on other petri dishes. Moreover, thecells on MWCNT/PAH thin films had a better morphology, and adhered steadily androbustly.Then MWCNT/PAH thin film based microfluidic chip was fabricated and culturedHela cells on the chip. Compared to the cells living in petri dishes modified withMWCNT/PAH thin film, the cells living in the microfluidic chip modifed withMWCNT/PAH thin film grew and proliferated more slowly, but there was nearly nodifference in other field. The cells living in the microfluidic chip modified withMWCNT/PAH thin films were still alive after48h culturing, and they could maintain apositive survival and proliferation in further culturing. The cells living in the PDMSmicrofluidic chip seemed to not adhere to substrate during the culturing, and grew and proliferated much more slowly.