Enhanced host-guest electrochemical recognition of herbicide MCPA using a β-cyclodextrin carbon nanotube sensor

► New sensor combining MWCNT, β-cyclodextrin and a polyaniline film. ► The proposed sensor has a high electrochemical sensitivity for determination of MCPA. ► The modified electrode developed exhibited high stability and lifetime. ► This sensor was used for the quantitative determination of MCPA in natural waters.