Direct Writing of Aligned Carbon Nanotubes across a Trench

Aligned and suspended carbon nanotubes can outperform randomly oriented networks in electronic biosensing and thin-film electronics. However, carbon nanotubes tend to bundle and form random networks. Here, we show that carbon nanotubes spontaneously align in an ammonium deoxycholate surfactant gel even under low shear forces, allowing direct writing and printing of nanotubes into electrically conducting wires and aligned thin layers across trenches. To demonstrate its application potential, we directly printed arrays of disposable electrical biosensors, which show femtomolar sensitivity in the detection of DNA and SARS-CoV-2 RNA.

Automated summary

Aligned carbon nanotubes can be directly written and printed into electrically conducting wires and thin layers using an ammonium deoxycholate surfactant gel. This technique shows potential for electronic biosensing and thin-film electronics, with demonstrated femtomolar sensitivity in DNA and SARS-CoV-2 RNA detection.