A flexible immunosensor based on the electrochemically rGO with Au SAM using half-antibody for collagen type I sensing

Abstract

For an efficient diagnostic, modern biosensing systems require miniaturization of portable electronic devices, should be high sensitivity to achieve detection at a low level, high specificity to the targeted molecule, and ease of operation. To address some of such tasks, this research demonstrates the fabrication of an electrochemically reduced graphene oxide (ERGO) on the surface of flexible, polymer-coated (polyethylene terephthalate, PET) covered with indium tin oxide (ITO) for biosensing application. Such fabricated ERGO film exhibited high electrical properties and a considerable amount of the oxide groups followed by thiol functionalization (tERGO). High stability and the immobilization of antibody receptors were achieved by covalent interactions between deposited gold nanoparticles (AuNPs) and reduced half-IgG collagen type I antibodies. Our biosensing immunosensor revealed a remarkable response to the complementary detected analyte collagen type I in the range of 10 pg/mL to 100 pg/mL. The performed immunosensor had a relatively low detection limit (LOD = 6 pg/mL) in comparison to the currently applied systems that are used for the detection of collagen. Therefore, it is presented an innovative attempt involving ideas for future pliable collagen immunosensors with high sensitivity and selectivity properties, which due to user-friendly handling and low cost of its production, and enabling for future application in the wearable sensors.

Keywords

• Electrochemical immunosensors
• Electrochemically reduced graphene oxide
• Nanogold particles
• Electrochemical impedance spectroscopy
• Collagen type I