Construction And Application Of Electrochemiluminescence Sensor Based On Molybdenum Nanomaterials

As the mortality rate caused by diseases is gradually increasing,the prevention and diagnosis of diseases have received great attention.The electrochemiluminescence（ECL）sensor has the advantages of high sensitivity,low interference background,and simple operation of the instrument.It has been widely used in the detection of disease markers,environmental monitoring,and food safety.Molybdenum-based nanomaterials have become important research materials for the construction of sensors because of their excellent electrical conductivity,good chemical stability and good biocompatibility.In this paper,molybdenum-based nanomaterials were used as substrate material and luminescence signal augmenting agent to construct sandwich-type ECL immunosensor,so as to achieve ultrasensitive detection of disease markers.The main research contents and results of this topic are as follows:1.Construction of sandwich-type electrochemiluminescence sensor based on Mo₂C/NCF nanomaterialsA quenching ECL immunosensor was constructed using molybdenum carbide nanoflower-polyethylenimin@N,S-doped graphene quantum dots（Mo₂C/NCF-PEI@N,S-GQDs）as luminophor and Si O₂/polydopamine（Si O₂/PDA）as secondary antibody marker for the ultrasensitive detection of cytokeratin 19 fragment（Cyfra21-1）.In the prescence of co-reactant K₂S₂O₈,Mo₂C/NCF-PEI@N,S-GQDs with larger specific surface area showed good ECL performance.As a receptor,Si O₂/PDA can produce energy resonance transfer with Mo₂C/NCF-PEI@N,S-GQDs,thus effectively quenching the ECL signal of Mo₂C/NCF-PEI@N,S-GQDs,and realizing the ultrasensitive detection of Cyfra21-1.Under the optimal experimental conditions,the concentration of Cyfra21-1 antigen showed a good linear relationship in the range of 0.01 pg/m L～100 ng/m L,and the detection limit（LOD）was 3.0 fg/m L（S/N=3）.The quenching ECL immunosensor presented high stability and sensitivity.2.Construction of sandwich-type electrochemiluminescence sensor based on MoS₂@Cu₂O-Ag nanomaterialsA sandwich-type ECL immunosensor was constructed based on molybdenum disulfide@cuprous oxide-silver nanoparticles（MoS₂@Cu₂O-Ag）composite nanomaterials for the detection of cardiac troponin I（c Tn I）.In this work,MoS₂@Cu₂O-Ag composite nanomaterials were used as the sensor platform,which provided the high specific surface area.In addition,with the help of lysine,cerium-doped zinc oxide nanoparticles（Ce:ZnO）were synthesized.The Ce O₂ redox pair(Ce⁴⁺/Ce³⁺)in Ce:ZnO would be quickly and reversibly converted,thus enhancing the ECL intensity of the luminophore nitrogen doped graphene quantum dots（NCQDs）,and realizing the sensitive detection of c Tn I.The ECL signal intensity and the logarithm of the c Tn I antigen concentration showed a linear relationship in the range of 10 fg/m L to 100 ng/m L,and the detection limit was 2.9 fg/m L（S/N=3）.The constructed immunosensor has good stability,excellent repeatability and high sensitivity.3.Construction of sandwich-type electrochemiluminescence sensor based on Mo₂C@C nanomaterialsA sandwich-type ECL immunosensor was constructed based on carbon encapsulated molybdenum carbide（Mo₂C@C）composite material for the detection of Cyfra21-1.Ga ON with high specific surface area was used as substrate to support large quantities of luminol.Luminol showed good ECL performance in the presence of co-reactive agent H₂O₂.In addition,Mo₂C@C nanospheres with core-shell structure were used as luminescent signal augmenting agent for the sensor.With good electrical conductivity,excellent stability and high specific surface area,Mo₂C@C could greatly improve the strength of ECL.Under the optimal experimental conditions,the detection range of the constructed sensor for Cyfra21-1 antigen is0.1 pg/m L～100 ng/m L,and the detection limit is 0.09 pg/m L,which can realize the ultrasensitive detection of Cyfra21-1.