Applications Of Molybdenum Disulfide Composite Materials In Electrochemical Sensing Technology

Electrochemical sensor is an analytical technology used to detect the immunological reaction between antigen and antibody to form a stable complex.Because of the high sensitivity,easy miniaturization,in-situ detection and low energy consumption,it has received extensive attention from researchers.Due to the excellent physical and chemical properties,molybdenum disulfide and its composites have been used extensively in many different scientific research fields,and are also one of the most popular materials involved in the construction of electrochemical sensors.At the same time,the composite materials based on molybdenum disulfide not only exhibit its own excellent material properties,but also possess good catalytic performance and biocompatibility compared with other materials.It can be seen that the molybdenum disulfide composite materials match well with the electrochemical sensor.Therefore,in this paper,we successfully prepared three molybdenum disulfide-based composite materials and applied them to the construction of electrochemical sensors,which achieved simple,rapid,effective and sensitive detection of multiple tumor markers.Sensitive detection provides effective references for clinical detection and bioanalysis.The concrete tasks are as follows:(1)An ultrasensitive label-free electrochemical sensor using Mo S₂/Ni Co heterostructures as an efficient signal enhancer was proposed for sensitive detection of procalcitonin.The Mo S₂/Ni Co heterostructures were synthesized by thermally depositing Mo S₂on Ni Co MOFs nanocubes,which were then functionalized with in situ grown palladium nanoparticles(Pd NPs)for electrochemically catalyze the reduction of hydrogen peroxide.The presence of Mo S₂/Ni Co heterostructures greatly enhanced the electrocatalytic activity of Pd NPs,thus the Pd NPs@Mo S₂/Ni Co modified electrode showed amplified response to hydrogen peroxide.The large specific surface of Pd NPs@Mo S₂/Ni Co greatly improved the loading of antibody of prepared immunosensor.Upon the incubation of the sensor with target procalcitonin,the electron transfer impendence increased and thus the chronoamperometric response decreased,leading to a highly sensitive immunosensing method for detection of procalcitonin.The proposed method showed a linear range of 1.0 pg/m Lto 50 ng/m L with a detection limit of0.360 pg/m L.The sensor has good accuracy and practicability for the diagnosis of PCT-related diseases,and can be widely used in the development of other biomarker immunosensors.(2)A sandwich electrochemical sensor for sensitive detection of non-small cell lung cancer was constructed based on the signal amplification strategy.Gold nanoparticles(Au NPs)functionalized oxygen-rich vacancy cobalt oxide(Au NPs@o-Co₃O₄)possessed higher electroactive surface area and conductivity,which improved the electrochemical performance of the platform improved.In addition,molybdenum disulfide(HCSs@Mo S₂-NH₂)loaded with copper rhodium nanoparticles(Cu Rh NPs)on hollow amino groups functionalized carbon spheres functionalized with amino groups was synthesized as signal amplification tag.The HCSs@Mo S₂-Cu Rh composite material increased the specific surface area and could bind more secondary antibodies(Ab₂),and the abundant catalytic active sites improved the electrocatalytic ability to hydrogen peroxide reduction.After incubating the sensing with target CYFRA 21-1 and then the labeled antibody,the electron rate was accelerated,which increased the amperometric response and realized the sensitive detection of CYFRA 21-1.Under the best experimental conditions,the sensor showed a good linear relationship between0.10 pg/m L and 25 ng/m L,the detection limit was 21.0 fg/m L,and it also showed expected performance in actual sample analysis.(3)Using Au NPs@3D Ti₃C₂T_x/Mo S₂as the signal amplification platform,a label-free electrochemical sensor for sensitive detection of insulin was constructed.Ti₃C₂T_x/Mo S₂with a three-dimensional structure could avoid the stacking and overlapping of the material,which led to larger specific surface area,improved the atomic utilization efficiency and increased the catalytic activity of materials.Meanwhile,the functionalization of Au NPs with 3D Ti₃C₂T_x/Mo S₂improved the biocompatibility,thereby increasing the loading capacity of insulin antibody and the electron transfer rate,which achieved sensitive detection of target insulin.Under the optimal experimental conditions,the sensor showed a linear response to insulin at 0.010?25 ng/m L,with a detection limit of 3.10 pg/m L,showing its potential application in clinical diagnosis.