A polymer based sensor for phosphate detection in water

This paper presents the detection of phosphate (PO4-
³
) concentration in water by using a commercial quartz crystal microbalance (QCM) sensor that was coated with a novel polymeric affinity layer for the first time. The QCM sensor was exposed to PO
4
⁻³
and chloride (Cl
⁻
) solutions in various concentrations to investigate the sensitivity of the affinity layer. Changes in the viscosity of a solution, and weak binding of ions onto the polymeric layer eliminated the effect of PO
4
⁻³
binding to the polymer and hardened the concentration detection. Therefore, we have proposed a new method in which an intermediate Cl
⁻
solution is applied before introducing the PO
4
⁻³
solution to detect the concentration level in a continuous flow.