Plasma Deposited Polyoxazoline Films Integration Into Spiral Microfluidics for the Targeted Capture of Size Selected Cells

Abstract

Biomolecules readily and irreversibly bind to plasma deposited Polyoxazoline thin films in physiological conditions. The unique reactivity of these thin films toward antibodies is driving the development of immunosensing platforms for applications in cancer diagnostics. However, in order for these coatings to be used as advanced immunosensors, they need to be incorporated into microfluidic devices that are sealed via plasma bonding. In this work, the thickness, chemistry and reactivity of the polyoxazoline films were assessed following plasma activation. Films deposited from methyl and isopropenyl oxazoline precursors were integrated into spiral microfluidic devices and biofunctionalized with prostate cancer specific antibodies. Using microbeads as model particles, the design of the spiral microfluidic was optimised to enable the size-based isolation of cancer cells. The device was tested with a mixed cell suspension of healthy and malignant prostate cells. The results showed that, following size-specific separation in the spiral, selective capture was achieved on the immunofunctionalised PPOx surface. This proof of concept study demonstrates that plasma deposited polyoxazoline can be used for immunosensing in plasma bonded microfluidic devices.

Electrochemical behavior of oxazoline‐based plasma polymers for biosensing applications

“…[ 10 ] Furthermore, the ability of these films to selectively capture cells in the high‐shear environment of a microfluidic device is maintained. [ 11 ] More recently, we have reported the use of POx thin films to functionalize electrodes in electrochemical biosensors. [ 12 ] Other groups have also shown that plasma‐polymer films can be used as part of a nanocomposite to functionalize electrodes and develop biosensors with a low limit of detection and good sensitivity and selectivity.…”