title: A novel dry method for surface modification of SU-8 for immobilization of biomolecules in Bio-MEMS.
abstract: SU-8 has been primarily used for structural elements and microfludics components in MEMS. Microsystems for biological applications require immobilization of biomolecules on the MEMS structures. In order to functionalize SU-8 for such purposes, the surface needs to be modified. In this paper, we report a novel dry method of surface modification of SU-8 which is compatible with standard microfabrication techniques. The surface obtained by spin coating SU-8 (2002) on silicon wafer was modified by grafting amine groups using pyrolytic dissociation of ammonia in a hotwire CVD setup. To demonstrate the presence of amine groups on modified SU-8 surface, the surface characteristic after modification was assessed using Fourier transform infrared spectroscopy. The change in SU-8 surface morphology before and after surface modification was investigated using atomic force microscopy. To show the utility of this process for application in Bio-MEMS, SU-8 microcantilevers were fabricated and subjected to the same surface modification protocol. Following this, the cantilevers were incubated first in a suspension of human immunoglobulin (HIgG) and then in FITC tagged goat anti-human IgG in order to demonstrate the utility of the surface modification performed. The efficacy of the process was assessed by observing the cantilevers under a fluorescence microscope.
authors.affiliation: School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Manoj
authors.initials: M
authors.lastname: Joshi
authors.forename: Nitin
authors.initials: N
authors.lastname: Kale
authors.forename: Rakesh
authors.initials: R
authors.lastname: Lal
authors.forename: V
authors.initials: V
authors.lastname: Ramgopal Rao
authors.forename: Soumyo
authors.initials: S
authors.lastname: Mukherji
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D001704:Biopolymers / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D007118:Immunoassay / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D008422:Materials Testing; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D001704:Biopolymers; D007074:Immunoglobulin G