Inkjet-printed bifunctional carbon nanotubes for pH sensing

The monitoring of pH values of liquids for environmental, industrial, and biological applications requires sensitive, stable, compact, and easy-to-use pH sensors. Here, we develop an inkjet printing process to deposit functionalized single-wall carbon nanotubes as both electron conduction and pH sensitive layers. Doping and de-doping of the carbon nanotubes by hydronium and hydroxide ions is the primary pH sensing mechanism. Multi-pass printing …