Design and Analytical Performances of a Diclofenac Biosensor for Water Resources Monitoring

Because the broadly consumed pain killer diclofenac (DCF) is a recognized pollutant, monitoring of its concentration routinely performed in surface waters. As valuable alternative to chromatographic and immunochemical assays, we developed piezoelectric immunosensor quantify DCF, first buffer (PBS) then river water samples. A sensing layer comprising DCF was built up on silica-coated quartz sensors using robust coupling chemistry. Binding highly affine monoclonal anti-DCF antibody monitored real time by crystal microbalance with dissipation (QCM-D) measurements from which were determined dissociation constant KD 0.24 nM an acoustic coverage 1120 ng/cm2 at saturation. On other hand, optical 260 combined nanoplasmonic measurement, giving hydration percentage 75% for monolayer. assay further set following competitive format binding inhibited solution. The sensor response expressed as frequency shift ?F inversely related dynamic range 15–46 limit detection (LoD) 9.5 (2.8 ?g/L) PBS. This eventually applied samples taken three different locations Seine Marne rivers. calculated these good agreement official data published French center analysis eaufrance.