title: Physicochemically modified silicon as a substrate for protein microarrays.
abstract: Reverse phase protein microarrays (RPMA) enable high throughput screening of posttranslational modifications of important signaling proteins within diseased cells. One limitation of protein-based molecular profiling is the lack of a PCR-like intrinsic amplification system for proteins. Enhancement of protein microarray sensitivities is an important goal, especially because many molecular targets within patient tissues are of low abundance. The ideal array substrate will have a high protein-binding affinity and low intrinsic signal. To date, nitrocellulose-coated glass has provided an effective substrate for protein binding in the microarray format when using chromogenic detection systems. As fluorescent systems, such as quantum dots, are explored as potential reporter agents, the intrinsic fluorescent properties of nitrocellulose-coated glass slides limit the ability to image microarrays for extended periods of time where increases in net sensitivity can be attained. Silicon, with low intrinsic autofluorescence, is being explored as a potential microarray surface. Native silicon has low binding potential. Through titrated reactive ion etching (RIE), varying surface areas have been created on silicon in order to enhance protein binding. Further, via chemical modification, reactive groups have been added to the surfaces for comparison of relative protein binding. Using this combinatorial method of surface roughening and surface coating, 3-aminopropyltriethoxysilane (APTES) and mercaptopropyltrimethoxysilane (MPTMS) treatments were shown to transform native silicon into a protein-binding substrate comparable to nitrocellulose.
authors.affiliation: Comprehensive Cancer Center, The Ohio State University, 473 W 12th Ave, #326 Columbus, OH 43210, USA.
authors.forename: A Jasper
authors.initials: AJ
authors.lastname: Nijdam
authors.forename: Mark
authors.initials: M
authors.lastname: Ming-Cheng Cheng
authors.forename: David H
authors.initials: DH
authors.lastname: Geho
authors.forename: Roberta
authors.initials: R
authors.lastname: Fedele
authors.forename: Paul
authors.initials: P
authors.lastname: Herrmann
authors.forename: Keith
authors.initials: K
authors.lastname: Killian
authors.forename: Virginia
authors.initials: V
authors.lastname: Espina
authors.forename: Emanuel F
authors.initials: EF
authors.lastname: Petricoin
authors.forename: Lance A
authors.initials: LA
authors.lastname: Liotta
authors.forename: Mauro
authors.initials: M
authors.lastname: Ferrari
mesh_terms: D000327:Adsorption; D000418:Albumins / Q000737:chemistry; D000818:Animals; D019921:Biotinylation; D003101:Collodion / Q000737:chemistry; D006801:Humans; D007477:Ions; D017646:Organosilicon Compounds; D011437:Propylamines; D040081:Protein Array Analysis / Q000295:instrumentation* / Q000379:methods*; D011506:Proteins / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D013379:Substrate Specificity; D013499:Surface Properties
chemical_list: D000418:Albumins; D007477:Ions; D017646:Organosilicon Compounds; D011437:Propylamines; D011506:Proteins; D012821:Silanes; C102833:(3-mercaptopropyl)trimethoxysilane; D003101:Collodion; C477625:amino-propyl-triethoxysilane; D012825:Silicon