A regulatable gap-electrical DNA sensor based on gold nanorods and single-walled carbon nanotubes

Infectious diseases, genetic diseases, and malignant tumor diseases are all related to DNA, but simple, unlabeled, and sensitive devices to detect DNA remain challenging. Carbon nanotubes biosensor has the advantages of low cost, fast detection speed, small size, and good biocompatibility. A new strategy gap device for DNA detection by using gold nanorods assembled in single-walled carbon nanotubes (AuNRs@SWCNTs) was developed. The AuNRs are synthesized with an average diameter of 56 +/- 4.8 nm and a length of 95 +/- 9.4 nm. Because of the anisotropic physical interaction between AuNRs and SWCNTs structure, when the SWCNTs grow on the surface of SiO2/Si substrate, the AuNRs are self-assembled orderly. The detection principle is based on the target DNA desorbing the probe DNA on the AuNRs to change its catalytic activity. The AuNRs are connected into nanowires along with the growth of the SWCNTs, thereby generating a conductance response. By adjusting the electrode gap, different detection limits were obtained. The 0.25 mu m electrode gap device detected target DNA with the detection limit of 1 pM.

Automated summary

Carbon nanotube biosensor is a low-cost, fast detection speed, small size, and good biocompatibility DNA detection device. Researchers have developed a new strategy gap device using gold nanorods assembled in single-walled carbon nanotubes to detect DNA. The device is based on the desorption reaction of the target DNA on the probe DNA on the gold nanorods, and different detection limits can be obtained by adjusting the electrode gap.