Anthraquinone functionalized carbon composite electrode: Application to ammonia sensing

A simple strategy has been used to covalently modify the glassy carbon spheres with anthraquinone moieties through the diazonium salt reduction. The derivatized glassy carbon spheres were used to modify the basal plane pyrolytic graphite electrode by immobilizing them on its surface and examining its electrochemical behaviour. The composite electrode has been used to detect trace level ammonia in the concentration range 5 × 10−8 to 3 × 10−5 M and it was successfully applied to detect low levels of ammonia present in natural samples like urine and soil.