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

The chemical binding of oligonucleotide/DNA on poly styrene-related polymeric surfaces has been investigated using contact angle measurements, x-ray photoelectron spectroscopy and gravimetric analysis. The results of the covalent attachment of the phosphorylated oligonucleotides using the hetero-bifunctional cross linker 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride to polystyrene-co-maleic anhydride (PSMAA) and polystyrene-co-maleic acid (PSMA) are described. The immobilization efficiency of covalently coupled 26-mer oligonucleotides to polymeric surfaces was estimated as 0.3 x 10(10) and 0.1 x 10(9) molecules mm(-2) for PSMA and PSMAA, respectively. The results suggest that, although the covalent binding on PSMAA per se is not capable of the high density of DNA required by micro-PCR applications, the method has the potential to be used as a cheap alternative for other low-cost, less DNA-sensitive applications such as disposable biosensors.