Nanoscale wires with external layers for sensors and other applications

An article, comprising:

• a field-effect transistor comprising a gate comprising a nanoscale wire, the nanoscale wire at least partially coated with polyethylene glycol.

An article, comprising:

• an ionic solution comprising an analyte;
• and
• a field-effect transistor exposed to the ionic solution, the field effect transistor comprising a gate comprising a nanoscale wire, the nanoscale wire at least partially coated with a polymer permeable to the analyte, wherein the polymer has an average pore size of between about 2 nm and about 10 nm.

A method, comprising:

• exposing an analyte to a nanoscale wire at least partially coated with a polymer, the polymer having an average pore size of at least the average size of the analyte and no more than 120% of the average size of the analyte, wherein the analyte has an average size of at least about 2 nm.

An article, comprising:

• a field-effect transistor comprising a gate comprising graphene at least partially coated with a polymer, the polymer containing pores having an average diameter of between about 5 nm and about 50 nm.

A method, comprising:

• exposing a protein to a field-effect transistor comprising a gate comprising graphene at least partially coated with a polymer, the polymer containing pores having an average diameter that is between 80% and 120% of the average diameter of the protein, whereby insertion of the protein into the pores alters the gating properties of the carbon nanotube.