Development of electrochemical devices for lead determination in whole blood samples

In this work, we developed a paper-based device coupled with a screen-printed carbon electrode (SPCE) for lead (Pb(II)) detection in whole blood, which can reduce interference from blood elements and shorten the conventional blood separation procedure. This paper-based device is composed of two parts. The first zone, as the sample zone for blood separation, is immobilized with a hemostatic agent, and the second zone, as the detection zone, is integrated with an electrode sensor. The metal was analyzed by square wave anodic stripping voltammetry (SWASV) using in situ plating of bismuth film. We optimized the separation and detection conditions for the lead detection (i.e., the concentration of the hemostatic agent, the concentration of bismuth, the volume of electrolyte solution, pH, the electrodeposition potential, and the deposition time). Under the optimal conditions, the linearity range of lead was found in the range from 40 to 120 µg/dL. The limit of detection (LOD) was found to be 34.8 and µg/dL based on 3σ method. The recoveries were in the range of 98-104%, with the highest relative standard deviation being 4.5%. Finally, we validated our proposed method by applying the paper-based device for lead detection in whole blood samples and compared the results with the ICP-MS method.