Electrochemical measurements were conducted using a PalmSens 4 potentiostat/impedance analyzer (PalmSens BV, Netherlands), controlled by PStrace software version 5.9. To prevent convection effects that can influence the electrochemical current response , chronocoulometry ( CC) was preferred as the method for CRP quantification. The following CC parameters were selected: t-equilibrium of 3 s, applied potential of 0.0 V vs. Ag/AgCl, t-interval of 0.1 s, analysis time of 200 s, whereas the current response was measured from 16 s to 180 s. For CRP detection, 4 μL of CRP solution with concentrations ranging from 0.01 ng mL -1 to 100 μg mL -1 were introduced in the sample inlet. Subsequently, following the completion of the antigen-nanobody binding reaction, 150 μL of PBS were introduced in the buffer inlet. The chronoamperometric signal was consistently recorded until the peak signal was completed. The detection principle and procedure for CRP detection using CC measurement are shown in Fig. .