Highly sensitive and selective amperometric nitrite sensor based on electrochemically activated graphite modified screen printed carbon electrode

A novel and sensitive amperometric nitrite sensor has been developed using electrochemically activated graphite (EAG) modified screen printed carbon electrode (SPCE) for the first time. The enhanced oxidation peak current (I _pa) with lower oxidation overpotential (E_pa) of nitrite is observed at EAG modified SPCE than that of electrochemically activated SPCE and graphite/SPCE. Under optimum conditions, the linear response of nitrite is found from 0.1 μM to 16.4 mM with a lower limit of detection of 38 nM. The sensitivity is calculated as 0.126 μA μM^-1 cm^-2. The EAG modified SPCE exhibits its high selectivity in the presence of common ions and biological co-active interfering species. In addition, the fabricated nitrite sensor shows a good repeatability, reproducibility and long term stability along with excellent practicality.