Surface plasmon resonance biosensor based on graphene oxide/silver coated polymer cladding silica fiber

•The RI sensitivity of the GO/silver SPR sensor reaches 3311.47 nm/RIU and 436.11 nm/RIU higher than silver film SPR sensor.•A high sensitivity of 0.4985 nm/(μg/mL) is reached for protein A and goat anti-human IgG modified on the sensor region.•A low limit of detection of human-IgG reaches 40 ng/mL.•The biosensor has advantages of high sensitivity, low limit of detection, inexpensive and simpler fabrication. A graphene oxide/silver coated polymer cladding silica fiber optical surface plasmon resonance (SPR) human IgG detection biosensor with a high sensitivity and a low limit of detection is presented. Due to the graphene oxide (GO), the intensity of the confined electric field surrounding the sensing layer can be enhanced, the sensitivity of refractive index (RI) of the graphene oxide/silver SPR sensor reached 3311 nm/RIU in the RI range of 1.3334–1.3731 compared with 2875 nm/RIU in the range of 1.3328–1.3739 of the silver film SPR sensor. Afterwards, SPR optical fiber biosensor was developed based on graphene oxide/silver coated optical fiber when staphylococcal protein A and goat anti-human IgG were immobilized on the surface of the graphene oxide film. The sensor can be used to detect different concentrations of human IgG, a high sensitivity of 0.4985 nm/(μg/mL) and a low limit of detection 0.04 μg/mL were observed. Therefore, the graphene oxide/silver film SPR human IgG detection biosensor with high sensitivity and low limit of detection shows a great promise for the future biochemical and biomedical application.