Novel Synthesis Of Polymer Brushes Via Click Chemistry And The Composites With Graphene Oxide For The Detection Of Tumor Markers

Cancer is one of the greatest threats to human health and a major cause of human death.Although the current medical condition is relatively perfect,there is still no feasible way to effectively cure it.So,early detection of disease-related biomarkers play a crucial role in the prevention and treatment of cancers.In the healthy human serum,Tumor markers(TMs)is less than 20 ng/mL,while the serum of the patients with cancer is much higher.Realize the amplification of TMs detection signal is of great significance for improving the sensitivity of detection.In this paper,the functional polymer brush was efficiently prepared by the union of cyano click chemistry and controlled/“living”radical polymerization(CRP).And the sensitive sandwich-type electrochemical immunosensor based on polymer brush/graphene oxide(GO)composites was prepared for the ultrasensitive detection of AFP.The contents of this paper are summarezed as follows.1.An electrochemical immunosensor based on poly(2-hydroxyethyl methacrylate)(PHEMA)/graphene oxide(GO)nanocomposite was designed in a simple way for the ultrasensitive detection of tumor markers(AFP as a model).PHEMA with excellent biocompatibility,provides a large number of sites for connecting signal molecules.After modified with signal molecules,the functional PHEMA significantly improved the sensitivity of electrochemical detection.In order to immobilize antibodies,GO was introduced and used to construct nanocomposite as a substrate.The designed AFP immunosensor showed favorable selectivity and excellent stability.At the same time it has a low detection limit of 0.403 pg/m L.2.A sensitive sandwich-type electrochemical immunosensor based on polyacrylonitrile-g-poly(hydroxyethyl methacrylate)(PAN-g-PHEMA)/graphene oxide(GO)composites was prepared for the ultrasensitive detection of tumor markers(AFP as a model).The functional polymer brush was efficiently prepared by the union of cyano click chemistry and CRP.The designed immunosensor showed a low limit of detection(LOD,~0.285pg/m L),with a wide detection range(2.5×10~1-2.5×10~4pg/m L)(R~2=0.9876).The electrochemical immunosensor also exhibited high sensitivity,favorable stability,excellent reproducibility and good selectivity towards AFP.3.The ultrasensitive sandwich-type electrochemical immunosensor based on polymer brush/graphene oxide(GO)was designed for quantitative detection of alpha fetoprotein(AFP).By modified GO to GO@Br,the GO@polyacrylonitrile(GO@PAN)was efficiently prepared via surface-initiated atom transfer radical polymerization(SI-ATRP).Benefit from the large number of cyano groups in PAN,the GO@Polymer Brush was synthesized herein through cynao click chemistry.High sensitivity was achieved through the GO@Polymer Brush connected to a large amount of signal molecules,which used PHEMA as side chains.The immunosensor showed a low limit of detection(LOD,~0.183 pg/m L),with a wide detection range(2.5×10~1-5×10~4pg/m L)(R~2=0.993).In addition,excellent selectivity,good reproducibility and stability were obtained for the immunosensor,which has a promising application for quantitative detection of other tumor markers in clinical diagnosis.