Abstract A novel colorimetric chemodosimeter for cyanide (CN−) and 1-allyl-4-[2-(4- hydroxyphenyl) ethenyl)]-quinolinium bromide (AHPEQB) was designed and synthesized by condensation and terminal N alkyl reaction. AHPEQB exhibited highly selective and sensitive recognition properties toward CN− over other competing anions in ethanol, a protic solvent, with a 1: 1 binding stoichiometry and a detection limit of 1.7× 10− 6 mol L− 1. ...