Electrochemical detection of thyroglobulin based upon biomimetic thyroid chemistry

We report on a novel nature-inspired electrochemical platform for the sensitive detection of thyroglobulin (Tg), a critical biomarker for monitoring treatment efficacy in patients with differentiated thyroid cancer following thyroidectomy. Current Tg diagnostic strategies typically require multiple complex reactions that require various washing steps and stringent experimental protocols. For this study, we have successfully developed a lactoperoxidase (LPO) based Ag nanoparticles (AgNP) and reduced graphene oxide (rGO) nanohybrid platform, on which LPO was immobilized through the creation of a self-assembled monolayer (SAM) of mercaptopropionic acid (MPA) followed by EDC/NHS activation. Cyclic voltammetry (CV) was employed to characterize the electrochemical behaviours of the rGO-AgNP nanohybrid, prior to and following the formation of the self-assembled monolayer (SAM). Electrochemical impedance spectroscopy (EIS) was used to further investigate the behaviour of the rGO-AgNP nanohybrid, following the immobilization of LPO. Our study has shown that the developed biosensor demonstrated rapid, sensitive, and selective Tg detection over a broad linear range of 4.0-90.0 ng/mL with a low limit of detection of 0.75 ng/mL, highlighting its strong potential for biological and clinical applications.