Covalent Functionalization for Biomolecular Recognition on Vertically Aligned Carbon Nanofibers

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• 作者：Sarah E. Baker ; Kiu-Yuen Tse ; Eve Hindin ; Beth M. Nichols ; Tami Lasseter Clare ; and Robert J. Hamers
• 刊名：Chemistry of Materials
• 出版年：2005
• 出版时间：October 4, 2005
• 年：2005
• 卷：17
• 期：20
• 页码：4971 - 4978
• 全文大小：320K
• 年卷期：v.17,no.20(October 4, 2005)
• ISSN：1520-5002

文摘

We compare two different strategies for covalently modifying carbon nanofibers with biologicalmolecules such as DNA. One method begins with a photochemical reaction between the nanofibers andmolecules bearing both a terminal olefin group and a protected amine group followed by deprotection toyield the free primary amine. The second method uses a chemical reaction of an aryldiazonium salt withthe nanofibers followed by electrochemical reduction to the primary amine. Both methods then link theprimary amines to thio-terminated DNA oligonucleotides. Our measurements show that both methodsyield DNA-modified carbon nanofibers exhibiting excellent specificity and reversibility in binding toDNA probe molecules in solution having complementary vs noncomplementary sequences. Quantitativemeasurements show that 2.3 × 10¹⁴ DNA molecules/cm² will hybridize to the DNA-modified nanofibersamples, approximately eight times higher than for a flat sample of glassy carbon functionalized in anidentical manner. Similar results were obtained comparing the amount of avidin that specifically bindsto biotin-modified surfaces of nanofibers and glassy carbon. Our results demonstrate the ability to covalentlyfunctionalize nanofibers via two different methods that both provide excellent biomolecular recognitionproperties. Since the photochemical method uses molecules that are highly insulating while the diazoniummethod uses molecules bearing aromatic groups that are expected to be conductive, these methods canbe used to prepare biologically modified nanofibers with a range of electrical properties that may beuseful for electrical sensing of specific biomolecules in solution.