Explore how immobilization strategies affected immunosensor performance by comparing four methods for antibody immobilization on electrode surfaces.

Among the common methods used for antibody immobilization on electrode surfaces, which is the best available option for immunosensor fabrication? To answer this question, we first used graphene-chitosan-Au/Pt nanoparticle (G-Chi-Au/PtNP) nanocomposites to modify a gold electrode (GE). Second, avian reovirus monoclonal antibody (ARV/MAb) was immobilized on the GE surface by using four common methods, which included glutaraldehyde (Glu), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS), direct incubation or cysteamine hydrochloride (CH). Third, the electrodes were incubated with bovine serum albumin, four different avian reovirus (ARV) immunosensors were obtained. Last, the four ARV immunosensors were used to detect ARV. The results showed that the ARV immunosensors immobilized via Glu, EDC/NHS, direct incubation or CH showed detection limits of 10 EID mL, 10 EID mL, 10 EID mL and 10 EID mL ARV (S/N = 3) and quantification limits of 10 EID mL, and 10 EID mL, 10 EID mL and 10 EID mL ARV (S/N = 10), respectively, while the linear range of the immunosensor immobilized via CH (0-10 EID mL ARV) was 10 times broader than that of the immunosensor immobilized via direct incubation (0-10 EID mL ARV) and 100 times broader than those of the immunosensors immobilized via Glu (0-10 EID mL ARV) or EDC/NHS (0-10 EID mL ARV). And the four immunosensors showed excellent selectivity, reproducibility and stability.