A protamine-conjugated gold decorated graphene oxide composite as an electrochemical platform for heparin detection

In this study, an effective electrochemical sensor was developed for heparin detection using a protamine-conjugated graphene oxide/gold (GO/Au) composite. Protamine is an antidote that can act as an affinity ligand for heparin. The GO was used as support for signal amplification, and Au nanoparticles (NPs) were employed to immobilize the protamine. This Au NPs also increasing the electron transfer rate and enhancing the signal response during protamine-heparin integration. The proposed affinity sensor had a simple fabrication process, a low detection limit (0.9 nM), a wide linear range (1.9 × 10 ⁻⁷ M to 1.5 × 10 ⁻⁹ M), high stability, and high selectivity in the detection of heparin.