LAUSR

Based on the successful design and preparation of Fe3O4@Au@polyethylene glycol (PEG)@chondroitin sulfate (CS) nanoparticles, a novel electrochemical biosensor was elaborately developed for MO determination by the drop coating method. This biosensor demonstrates ultra-low fouling properties in complex biological systems, especially in whole serum. Only 2.40% of the differential pulse voltammetry (DPV) signal changes are shown in the resistance test of electrode interface to 100% goat serum. The constructed biosensor also presented a good selectivity (DNA samples for M1, M2 and M3give a response around 14.2-21.4%of that obtained by the target analyte), reproducibility (the relative standard deviation (RSD) is only 4.82%) and storage stability (93.2% of the initial response is maintained after 20 day). Moreover, this biosensor exhibits high analytical performance with a wide line arranges (10-17 M ∼ 10-12 M) in buffer, even in 100% goat serum. In both cases, a low limit of detection (LOD) of 3.3 aM(S/N = 3)is showed. To our knowledge, a few examples reported the application of electrochemical biosensors to the direct ultrahigh sensitive determination of MO, especially in whole serum.