Modifying the Morphology of Silicon Surfaces by Laser Induced Liquid Assisted Colloidal Lithography

Protein Patterning on Microtextured Polymeric Nano-brush Templates Obtained By Nanosecond Fibre Laser

Micropatterned polymer brushes have attracted attention in several biomedical areas, i.e., tissue engineering, protein microarray, biosensors etc., for precise arrangement of biomolecules. Herein, we report a facile and scalable approach to create microtextured polymer brushes with the ability to generate different type of protein patterns. Nanosecond fibre laser was exploited to generate micropatterns on polyPEGMA (poly(ethylene glycol) methacrylate) brush modified Ti alloy substrate. Surface initiated atom transfer radical polymerisation was employed to grow PolyPEGMA brush (11-87 nm thick) on Ti alloy surface immobilized with initiator having an initiator density (σ*) of 1.5 initiators/nm² . Polymer brushes were then selectively laser ablated and their presence on non-textured area was confirmed by atomic force microscopy, fluorescence microscopy and X-ray photoelectron spectroscopy. Spatial orientation of biomolecules was first achieved by non-specific protein adsorption on areas ablated by the laser, via physisorption. Further, patterned brushes of polyPEGMA were modified to activated ester that gave rise to protein conjugation specifically on non-laser ablated brush areas. Moreover, the laser ablated brush modified patterned template was also successfully utilized for generating alternate patterns of bacteria. This promising technique can be further extended to create interesting patterns of several biomolecules which are of great interest to biomedical research community. This article is protected by copyright. All rights reserved.