Single-walled carbon nanotubes chemiresistor aptasensors for small molecules: picomolar level detection of adenosine triphosphate

Here we report single walled-carbon nanotubes (SWNTs)-based chemiresistor aptasensors for highly sensitive and selective detection of weakly or uncharged molecules using the displacement format. As a proof-of-concept we demonstrate the detection of ATP, a small weakly charged molecule, by displacement of the ssDNA anti-ATP aptamer hybridized to a small capture oligonucleotide covalently attached on SWNTs, with picomolar sensitivity and selectivity over GTP.