A sandwich-type electrochemical sensor based on RGO-CeO-Au nanoparticles and double aptamers for ultrasensitive detection of glypican-3.

A sandwich-type electrochemical aptasensor for ultrasensitive detection of glypican-3 (GPC3) was constructed using GPC3 aptamer (GPC3) labelled reduced graphene oxide-cerium oxide-gold nanoparticles (RGO-CeO-Au NPs) as the signal probe and the same GPC3 as the capture probe. The electrochemical redox properties of CeO (Ce/Ce) in the RGO-CeO-Au NPs indicate the electrochemical signals. When the target GPC3 was present, an "aptamer-protein-aptamer" sandwich structure was formed on the sensing interface due to the specific binding between the protein and aptamers, resulting in an increased electrochemical redox signal detected by differential pulse voltammetry (DPV) technique.

Sandwich-type supersensitive electrochemical aptasensor of glypican-3 based on PrGO-Hemin-PdNP and AuNP@PoPD.

A new sandwich-type electrochemical biosensing platform was developed by gold @polyphthalenediamine nanohybrids (AuNP@PoPD) as the sensing platform and phosphorus doped reduced graphene oxide-hemin-palladium nanoparticles (PrGO-Hemin-PdNP) as the signal amplifier for phosphatidylinositol proteoglycan 3 (GPC3). AuNP@PoPD, co-electrodeposited into the screen printed electrode with high conductivity and stability, is dedicated to assembling the primary GPC3 aptamer (GPC3). The second GPC3 immobilized on the high conductivity and large surface area of PrGO-Hemin-PdNP was utilized as an electrochemical signal reporter by hemin oxidation (PrGO-Hemin-PdNP-GPC3).