The detection of brucellosis antibody in whole serum based on the low-fouling electrochemical immunosensor fabricated with magnetic Fe3O4@Au@PEG@HA nanoparticles

It is a novel competitive challenge for electrochemical biosensor to directly, rapidly and ultrasensitively detect the disease markers in the whole serum due to biofouling caused by the complexity of actual samples. In this paper, poly (ethylene glycol) (PEG) and hyaluronic acid (HA) were utilized to modify Fe3O4 @Au nanoparticles (NPs). Based on the successfully preparation and characterization of Fe3O4 @Au@PEG@HA NPs with TEM, SEM, XRD, FTIR and EDS, respectively, a novel immunosensor of brucellosis with high selectivity, sensitivity and almost perfect protein-resistant properties in various external environments, especially, in complex biological systems was fabricated. More importantly, this immunosensor is capable of assaying brucellosis antibody in 100% serum without suffering from any significant biological interference. In addition, a wide linear response range from 10(-15) g mL(-1) to 10(-11) g mL(-1) towards antibody in 100% serum and a low limit of detection (LOD) of 0.36 fg mL(-1) (3 sigma, n = 13) are demonstrated, which indicates that this immunosensor has a promising potential in clinical diagnosis.