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 PO₄^-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 PO₄^-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 PO₄^-3 solution to detect the concentration level in a continuous flow.