Preparation And Biosensing Performances Of Functional Polymers/Au, Ni-based Nanocomposites

In the thesis,functional polymers as the substrate material,a series of new material system was designed and prepared,and a series of high-performance biosensors were constructed,which were realized the high sensitive specificity of detection disease markers such as glucose,carcinoembryonic antigen,thrombin,prostate antigen.At the same time,the application of in the actual sample detection was studied.This thesis mainly includes the following five aspects:（1）Ni（OH）₂@PEDOT-rGO nanocomposite electrode materials were fabricated by a simple,fast and controllable electrochemical deposition method using graphene oxide（GO）,3,4-ethylenedioxythiophene（EDOT）and nickel nitrate（Ni（NO₃）₂）as raw materials and a non-enzyme glucose sensor was constructed.The influence of PEDOT-rGO electrochemical deposition cycles,Ni（OH）₂ deposition time,Ni（OH）₂ deposition potential,the concentration of NaOH solution,the applied potential on the morphplogy and the electrocatalytic performance of Ni（OH）₂@PEDOT-rGO nanocomposite electrode materials was studied in detailed,respectively.And the preparation technological parameters and detection conditions were optimized.Ni（OH）₂@PEDOT-rGO nanocomposite electrode materials were characterized via scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,cyclic voltammetry（CV）,current-time curve（i-t）,X-ray photoelectron spectroscopy（XPS）and Raman spectroscopy（Raman）.The selectivity,stability and repeatability of the non-enzyme glucose sensor were also investigated.In addition,we also studied its application in actual sample detection.The results indicated that the optimum conditions were as follows:PEDOT-rGO electrochemical deposition cycles was 13 cycles,Ni（OH）₂ deposition time was 400 s,Ni（OH）₂ deposition potential was-0.9 V,the concentration of NaOH sulotion was 0.1 mol L^-1 and the applied potential was 0.55 V.Ni（OH）₂ nanoparticles with an average particle size about 10 nm are uniformly grown on PEDOT-rGO hybrid film with rough surface.Under optimal condition,the non-enzyme glucose sensor exhibits a wide detection range(2?7100μmol L^-1,R²=0.998),a low detection limit(0.6μmol L^-1,S/N=3),a high sensitivity(346μA mM^-1 cm^-2)and an ultrafast response time（less than 1 s）.In addition,the senor exhibits better selectivity,stability and repeatability.The as-prepared sensor was successfully used to determine glucose in the real samples.（2）Ni₃S₂@PEDOT-rGO nanocomposite electrode materials were fabricated via an easy-to-controlcyclic voltammetry methodusinggrapheneoxide（GO）,3,4-ethylenedioxythiophene（EDOT）,nickel chloride（NiCl₂）and thiourea（CS（NH₂）₂）as raw materials and a non-enzyme glucose sensor was constructed.The influence of Ni₃S₂electrochemical deposition cycles,Ni₃S₂ scan rate,the concentration of NaOH solution and the applied potential on the morphplogy and the electrocatalytic performance of Ni₃S₂@PEDOT-rGO nanocomposite electrode materials was studied in detailed,respectively.And the preparation technological parameters and detection conditions were optimized.The electrode materials were characterized by using scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）,X-ray diffraction（XRD）,cyclic voltammetry（CV）and current-time curve（i-t）.The selectivity,reproducibility,repeatability and stability of the sensor were also investigated.In addition,we also studied its application in real sample.The optimum technological parameters were as follows:Ni₃S₂ electrochemical deposition cycles was 2 cycles,Ni₃S₂ scan rate was 10 mV s^-1,the concentration of NaOH solution was 0.1 mol L^-1 and the applied potential was 0.5V.Ni₃S₂ nanochains were uniformly grown on PEDOT-rGO hybrid film with rough surface.Under the optimum conditions,the sensor exhibited a wide detection range(2⁹105μmol L^-1),low detection limit(0.46μmol L^-1,S/N=3),high sensitivity(2222μA mM^-1 cm^-2)and fast response time（<2 s）.Moreover,the sensor exhibited good selectivity,reproducibility,repeatability and stability.More importantly,the sensor was successfully used to determine glucose in human blood serum samples and the results was a good agreement with hospital test results,indicating the electrode material has promising potential in estimating the glucose concentration in human serum.（3）Au/PEDOT-rGO nanocomposite electrode materials were fabricated via a facile and controllable electrochemical deposited method using graphene oxide（GO）,3,4-ethylenedioxythiophene（EDOT）and chloroauric acid（HAuCl₄·4H₂O）as raw materials.Carcinoembryonic antigen（CEA）aptamer biosensor was constructed by introducing CEA aptamer on the surface of Au@PEDOT-rGO nanocomposite electrode material.The influence of CEA aptamer incubation temperature,incubation time and pH value on the sensor performance was investigated in detailed,respectively.And the detection conditions were optimized.The morphology and electrochemical performances of Au/PEDOT-rGO nanocomposite electrode materials were characterized by using scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）,X-ray diffraction（XRD）,cyclic voltammetry（CV）,electrochemical impedance spectroscopy（EIS）and differential pulse cyclic voltammetry（DPV）.The optimum detection conditions were as follows:CEA aptamer incubation temperature was 37℃,incubation time was 30min and pH value was 7.4.Au nanoflowers were uniformly grown on PEDOT-rGO hybrid film with rough surface.Under the optimum conditions,the CEA aptamer sensor exhibited a wide detection range(10^-6μg m L^-11μg mL^-1),a low dection limit(3.3*10^-7μg mL^-1).Meanwhile,the sensor exhibited good selectivity,repeatability and stability.More importantly,the as-prepared sensor was successfully used to determine CEA in human blood serum samples,indicating Au/PEDOT-rGO nanocomposite electrode material is expected to be an ideal material for the new CEA sensor.（4）Au/PANI nanocomposite electrode materials were prepared via a facile and controllable galvanostatic method using aniline（ANI）and chloroauric acid（HAuCl₄·4H₂O）as raw materials.Thrombin aptamer biosensor was constructed by introducing thrombin aptamer on the surface of Au/PANI nanocomposite.The influence of aniline deposition time,aniline concentration,deposition current density,thrombin aptamer incubation temperature,incubation time and pH value on the sensor performance was investigated in detailed,respectively.And the preparation technological parameters and detection conditions were optimized.The morphology and electrochemical performances of Au/PANI nanocomposite electrode materials were characterized by using scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）,X-ray diffraction（XRD）,cyclic voltammetry（CV）and differential pulse cyclic voltammetry（DPV）.The optimum conditions were as follows:aniline deposition time was 1800s-7200 s-7200 s,aniline concentration was 0.5 mol L^-1,deposition current density was0.06 mA cm^-2-0.03 mA cm^-2-0.015 mA cm^-2,thrombin aptamer incubation temperature was 37℃,incubation time was 40 min and pH value was 7.4.PANI presented nanowire array structure.Under the optimum conditions,the as prepared sensor exhibited a wide detection range(10^-1210^-99 g mL^-1)and a low detection limit(3.3×10^-13 g m L^-1).Meanwhile,the sensor exhibited good selectivity,repeatability and stability.More importantly,the as-prepared sensor had a great potential in the field of actual sample detection.（5）Au/PDA nanocomposite electrode materials were prepared via a facile electrochemical deposited method.Then prostate antigen（PSA）aptamer sensor was constructed by introducing polypeptide and PSA aptamer.The PSA incubation time was optimum.The morphology,hydrophilia and electrochemical detection performances were characterized by using scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）,static water contact angle and electrochemical impedance spectroscopy（EIS）.The results indicated that when the incubation time was 30 min,the sensor exhibited an excellent detetion performance.The detection range was 0.0001 ng m L^-1200 ng mL^-1 and the detection limit was 0.00003 ng mL^-1.Meanwhile,the sensor exhibited good selectivity,reproducibility and stability.In particular,the results obtained by the sensor for actual sample detection showed its good application potential.