| Prostatic cancer,is recognized as a killer of men’s health all over the world.As an important cancer biomarker,prostate-specific antigen plays a vital role in the process of screening and diagnosis of prostatic cancer.At present,the development of advanced analysis technology for the detection of prostate-specific antigen becomes a significant topic.Electrochemical immunosensors combine highly sensitive electrochemical sensing techniques with specific immunologic recognition reactions.Electrochemical immunosensors have been applied for the detection of various cancer biomarkers due to their advantages such as high sensitivity,good selectivity,small sample requirement,low cost and so on.In recent years,to realize sensitive detection of cancer biomarkers,electrocatalysts are usually used to construct electrochemical immunosensors for signal amplification.The sensitivity of electrochemical immunosensor is largely determined by the catalytic activity of electrocatalyst,so the development of electrocatalyst with excellent catalytic activity is beneficial to sensitive detection of PSA.In this paper,three novel electrocatalyst nanomaterials were prepared and used to construct electrochemical immunosensors for the highly sensitive detection of PSA.The main contents and innovations of this thesis are as follows:（1）Using ZIF-67 nanocubes as a template,by the experimental procedures of Ni2+ion exchange,calcination and CeO2 QDs growth,the Ni CoO2@CeO2 hollow nanocubes with high oxygen evolution reaction（OER）activity were prepared and used as catalytic labels for constructing a sandwich-type electrochemical immunosensor.Highly sensitive detection of PSA was realized due to the high OER catalytic current response.The prepared immunosensor showed a broad linear range from 10-44 to 50 ng mL-11 for PSA detection,with a low detection limit of 10 fg mL-1（S/N=3）.Moreover,this immunosensor was successfully used for detecting PSA in a serum sample.The main innovation point of this work:the combination of immunosensing with OER of high current response for the first time,and thus provides a new method of signal amplification for constructing highly sensitive electrochemical immunosensor.（2）Using CNTs as a nanocarrier,by the experimental procedures of amination and Co3O4 QDs growth,Co3O4 quantum dots（QDs）-aminated carbon nanotubes（ACNTs）with high electrocatalytic activity toward the reduction of hydrogen peroxide were prepared and used as catalytic labels for constructing a sandwich-type electrochemical immunosensor.Highly sensitive detection of PSA was realized due to the large current response of H2O2 reduction reaction.The prepared immunosensor showed a broad linear range from 10-44 to 100 ng mL-11 for PSA detection,with a low detection limit of 20 fg m L-1（S/N=3）.Moreover,this immunosensor was successfully used for detecting PSA in a serum sample.The main innovation point of this work:compared with large-grained Co3O4 nanoparticles,the Co3O4 QDs with ultrasmall size show higher electrocatalytic activity,the higher reduction current can be got.Thus,the signal amplification of immunosensor can be realized.（3）Using Cu2O as a nanocarrier,by the experimental procedure of Co（OH）2nanosheets growth and sulfofication with Na2S aqueous solution,Cu2S@Co3S4 with high electrocatalytic activity toward the reduction of hydrogen peroxide were prepared and used for the construction of label-free electrochemical immunosensor.Highly sensitive detection of PSA was realized due to the large current response of H2O2 reduction reaction.The prepared immunosensor showed a broad linear range from 10-22 to 100 ng mL-11 for PSA detection,with a low detection limit of 4.2 pg mL-1（S/N=3）.Moreover,this immunosensor was successfully used for detecting PSA in a serum sample.The main innovation point of this work:developing a novel nanomaterial with outstanding electrocatalytic activity toward the reduction of hydrogen peroxide,which is beneficial to the construction of highly sensitive electrochemical immunosensor. |
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