Abstract Submitted to the    NANOTUBE'04 Conference:

The immobilization of DNA oligonucleotides on single-walled carbon nanotube (SWNT) multilayer films is a crucial step for any application in the field of DNA microarrays. It determines the efficacy of hybridization and influences the signal strength for the detection. For the immobilization of DNA, we used SWNT multilayer films made from the chemical reaction using the cut SWNTs and the chemical reagents onto an amine-terminated glass. These SWNTs multilayer films were constructed via consecutive condensation reactions that created stacks of SWNT layers linked together with the aid of a linker molecule 4,4’-oxydianiline (ODA) and a condensation reagent. The aminated or carboxylated DNA oligonucleotides were covalently immobilized to the carboxylated or aminated SWNTs multilayer films via amide bonds by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride-catalyzed amidation reaction. Absorbance spectrophotometry (UV-vis-NIR) analysis indicated that the surface density of SWNT films increased uniformly according to the number of reaction cycles. Scanning electron microscopy measurements results showed that the SWNT multilayer film thoroughly and uniformly covered the substrate surface. The DNA oligonucleotide probe attached onto SWNT multilayer films and subsequent hybridization has been investigated using X-ray photoelectron spectroscopy and fluorescence-based measurements of DNA hybridization. The resultant DNA-attached SWNT multilayer films were shown to exhibit excellent specificity and chemical stability under the conditions of DNA hybridization.