Controllable Synthesis Of Three Dimensional Multi Metal Nanomaterials And Their Applications In Electrochemical Immunosensors

Cancer has become one of the major diseases that threaten human life and health,so?early detection?and?early treatment?are effective ways of cancer prevention and treatment.Studies have shown that the development of cancer is related to certain tumor markers and their quantitative changes in patients'blood,body fluids or tumor cells.Therefore,the detection of tumor markers is very important for early diagnosis,classification,prognosis and treatment of cancer.It has a good practical sample analysis and clinical application value to construct an efficient and sensitive detection method.The purpose of this paper is to design a controllable synthesis of noble metal nanomaterials with beautiful appearance and excellent performance as a stable sensing interface or signal amplification label.Based on this,an electrochemical immunosensor is constructed to achieve accurate analysis and detection of tumor markers and expand its practical application in human serum samples.The main contents are as follows:?1?A novel electrochemical immunosensor for highly sensitive detection of prostate-specific antigen using 3D open-structured Pt Cu nanoframes for signal amplificationThe highly opened three-dimensional?3D?Pt Cu hollow nanoframes?Pt Cu HNFs?were synthesized by a one-pot solvothermal method with cetyltrimethylammonium chloride and trishydroxymethyl aminomethane as co-structuring directors.And polylysine was used to disperse Pt Cu HNFs,improve the biocompatibility and prevent its aggregation.In the light of the boosted currents for hydrogen peroxide?H₂O₂?reduction catalyzed by Pt Cu HNFs,a new type of label-free ultrasensitive electrochemical immunosensor was fabricated for detecting prostate-specific antigen?PSA?.Under the optimal conditions,the immunosensor displayed a wider linear range of 0.01–75 ng mL^–1,with a lower detection limit of 0.003 ng mL^–1?S/N=3?,an outstanding selectivity,good reproducibility and favorable stability towards PSA detection,indicating its prospective applications in clinical diagnosis.?2?Threedimensionalsea-urchin-likePdAu Cu nanocrystals/ferrocene-graftedpolylysine as an efficient probe to amplify the electrochemical signals for ultrasensitive immunoassay of carcinoembryonic antigenThree dimensional sea-urchin-like PdAu Cu nanocrystals?PdAuCu NCs?were directly synthesized with polyethylene oxide as a growth-directing agent by a facile one-step aqueous method without any organic solvent.Meanwhile,ferrocene-grafted-polylysine was obtained by covalent linkage of Fc with PLL via Schiff-base reaction.A novel sandwich-like immunosensor was efficiently fabricated for detection of carcinoembryonic antigen?CEA?with PdAuCu NCs/ferrocene-grafted-polylysine as the label of secondary antibodies?Ab₂?and Au nanoparticles?Au NPs?as the substrate material.The resultant immunosensor shows linear relationship of the electrochemical responses with the CEA concentrations within a broader linear range(0.001–100 ng mL^–1)and a lower detection limit(0.23pg mL^–1,S/N=3),along with satisfactory reproducibility,better stability and superior selectivity.Furthermore,the immunosensor was explored for practical assay of CEA in human serum samples with accredited results.?3?Simple one-pot aqueous synthesis of 3D superstructured Pt Co CuPd alloyed tripods for ultrasensitive immunoassay of cardiac troponin IFour-metallic Pt Co CuPd hierarchical branch-like tripods?HBTPs?were directly synthesized with the aid of F127 by a green one-pot aqueous method without any seed or organic solvent.A Pt Co CuPd HBTPs-based label-free immunosensor was fabricated by virtue of the catalytic signals of K₃Fe?CN?₆ to quantitatively detect cardiac troponin I?cTnI?.Under the optimal conditions,the as-developed immunosensor exhibited a wide linear range(0.01–100 ng mL^–1)and a low detection limit(2 pg mL^–1,S/N=3)for the assay of cTnI,along with the acceptable reproducibility,specificity and long-term stability.Furthermore,the as developed immunosensor is further implemented for the assay of cTnI in actual serum sample.