Feasibility of using carboxylic-rich polymeric surfaces for the covalent binding ofoligonucleotides for microPCR applications

Abstract

The chemical binding of oligonucleotide/DNA on polystyrene-related polymericsurfaces has been investigated using contact angle measurements, x-rayphotoelectron spectroscopy and gravimetric analysis. The results of the covalentattachment of the phosphorylated oligonucleotides using the hetero-bifunctionalcross linker 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride topolystyrene-co-maleic anhydride (PSMAA) and polystyrene-co-maleic acid(PSMA) are described. The immobilization efficiency of covalently coupled 26-meroligonucleotides to polymeric surfaces was estimated as 0.3 × 1010 and 0.1 ×109 molecules mm−2 for PSMA and PSMAA, respectively. The resultssuggest that, although the covalent binding on PSMAA per se is notcapable of the high density of DNA required by micro-PCR applications,the method has the potential to be used as a cheap alternative for otherlow-cost, less DNA-sensitive applications such as disposable biosensors.