The synthesis and characterization of a new Co(III) complex of a salphen-type Schiff base ligand, (E)-2-{[(2-aminopyridin-3-yl)imino]methyl}-4,6-di-tert-butylphenol (HL), are reported. The characterization has been carried out using X-ray single crystallographic, thermogravimetric, and spectroscopic techniques. The complex has been combined with polyvinyl chloride (PVC) membrane of various compositions and tested as an electrochemical electrode towards recognition of several anions. The electrode exhibits exceptional electrochemical recognition for the nitrite (NO⁻ ₂ ) anion in aqueous media. The electrode exhibited a linear response to NO⁻ ₂ with a detection limit of 5.76μM and displayed a linear Nernstian slope over the nitriteconcentration range of 1.0 × 10⁻⁵–1.0 × 10⁻¹ M in the pH range of 3–7 and a fast response time of less than 10 seconds. Theoretical calculations showed that the sensing could be via anion exchange in the Co(III) complex.