DNA−CNT Nanowire Networks for DNA Detection

• Published in: Journal of the American Chemical Society 2011-03, Vol.133 (10), p.3238-3241
• Main Authors: Weizmann, Yossi, Chenoweth, David M, Swager, Timothy M
• Format: Article
• Language: English
• Subjects: DNA - analysis; DNA Probes - chemistry; Electric Conductivity; Humans; Microscopy, Electron, Scanning; Nanotubes, Carbon - chemistry; Nanowires - chemistry; Nucleic Acid Hybridization - methods
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja109180d

The ability to detect biological analytes in a rapid, sensitive, operationally simple, and cost-effective manner will impact human health and safety. Hybrid biocatalyzed-carbon nanotube (CNT) nanowire-based detection methods offer a highly sensitive and specific platform for the fabrication of simple and effective conductometric devices. Here, we report a conductivity-based DNA detection method utilizing carbon nanotube−DNA nanowire devices and oligonucleotide-functionalized enzyme probes. Key to our sensor design is a DNA-linked-CNT wire motif, which forms a network of interrupted carbon nanotube wires connecting two electrodes. Sensing occurs at the DNA junctions linking CNTs, followed by amplification using enzymatic metalization leading to a conductimetric response. The DNA analyte detection limit is 10 fM with the ability to discriminate single, double, and triple base pair mismatches. DNA−CNT nanowires and device sensing gaps were characterized by scanning electron microscopy (SEM) and confocal Raman microscopy, supporting the enhanced conductometric response resulting from nanowire metallization.