Development of a lab-on-chip electrochemical immunosensor for detection of Polycyclic Aromatic Hydrocarbons (PAH) in environmental water

Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants found in water, soil, and air, and human exposure to these compouds is a concerning health hazard. Current methods used to determine PAHs in water require complex analysis, are time-consuming and not portable. To overcome these difficulties, this work presents the integration of electrochemical techniques in combination with a tailored immunoassay method that aims to detect Benzo[a]pyrene (BaP) in water. Nanoparticles were used as a substrate for the antibodies that are the main biomolecules of our immunoassay. Covalent immobilization was carried out, where the antibody linking occurs through chemical processes with one of its functional groups (carboxyl) to amine groups generated in the surface of the nanoparticles. This covalent immobilization method provides a strong bond between the antibody to the nanoparticle, offering then a very reliable protocol for BaP detection. The limits of detection obtained (0.5ng/ml) are comparable to those of available state-of-the-art tools and close to the values requested by European Drinking Water Directive (0.01ng/ml). It also presents a linear range of (13.7 to 123 ng/ml) that is practical in the detection of PAHs in water, The use of a magnetic platform offers the opportunity to integrate it into a portable solution that could be used for in situ monitoring of PAH in water. Having an in situ monitoring device is important for real-time and early detection of potential presence of PAHs in water. This is a potential solution for domestic testing that would allow consumers to control the quality of their drinkable water.