Electrochemical determination of folic acid in triple-matrix biofluids: a PAni-DES and Au/Printex L6@Chitosan enhanced lab-made screen-printed sensor.

The development and application of a highly sensitive electrochemical screen-printed electrode (SPE) for the determination of folic acid (FA) is presented. The SPE was fabricated on a polyethylene substrate using customized graphite ink and modified with Printex L6 carbon (PL6C) dispersed in chitosan (Chi). Gold (Au) nanoparticles were electrodeposited onto the SPE surface, followed by electropolymerization of polyaniline (PAni) in a deep eutectic solvent (DES), enhancing the electrochemical performance.