Fabrication of new solid state phosphate selective electrodes for environmental monitoring

A highly selective and sensitive phosphate sensor has been fabricated by constructing a crystal disk consisting of variable mixtures of aluminium powder (Al), aluminium phosphate (AlPO₄) and powdered copper (Cu). The membrane sensor exhibits linear potential response in the concentration range of 1.0 × 10⁻¹ to 1.0 × 10⁻⁶ mol L⁻¹. The proposed sensor also exhibits a fast response time of <60 s. Its detection limit is lower than 1.0 × 10⁻⁶ mol L⁻¹. The electrode has a long lifetime and can be stored in air when not in use. The selectivity of the sensor with respect to other common ions is excellent.