Preparation Of MoS₂ Nanomaterial Modified Electrode And Their Electrochemical Sensing Properties

In recent times,presence of contaminants in the environment is one of most concerned issues regarding human health.Environmental contaminants possess the ability to affect the structure and physiological function of human body,thus it is necessary to develop a sensitive and rapid method to detect them.Electrochemical sensing methods have emerged as sensitive,selective and convenient detection techniques with low cost,high accuracy and simple operation.Recent developments in the field of nanoscience offer new possibilities for novel sensor designs based on advance functional nanomaterials.The enhanced electrochemical performance of sensors is mainly achieved by chemical modifications of bare electrode surfaces using the signal amplification of different nanomaterials.Among various advance nanomaterials,molybdebum disulfide(Mo S2)has emerged as a popular member and withdrawn immense attention due to its extraordinary electronic and layered morphology.However,compared with metal and graphene,the conductivity of Mo S2 has a certain gap,which limits the application.Herein,advance Mo S2 nanomaterials have been synthesized to improve the conductivity and promote catalytic activity of Mo S2,using for the sensitive detection of bisphenol A and glucose was achieved.The main research contents and conclusions and conclusions are as follows:(1)A sensitive electrochemical sensing system was fabricated based on two dimensional(2D)Mo S2 nanosheets(Mo S2),gold nanoparticles(Au NPs)and polypyrrole(PPY)nanocomposite modified glass carbon electrode(GCE)for glucose detection.Modification of Mo S2 nanosheets with gold nanoparticles(Au NPs)can significantly increase the effective electrode surface area and provide high conductivity to promote electron transfer reactions.Polypyrrole(PPY)which belongs to conducting polymers and Mo S2 nanostructures exhibits synergistic effects to accelerate electron transport at electrode surface which improve the sensitivity of the sensing system towards glucose detection.Cu(II)/Cu(III)redox couple was utilized as catalytic center which converted glucose into gluconolactone.After optimizing the experimental conditions,the electrode based on Mo S2-PPY-Au NPs composite can detect glucose linearly within 0.1-80 n M with a detection limit of 0.085 n M.In addition,the approach showed high specificity,good stability and repeatability.The electrode was found suitable for glucose detection in human serum samples with recoveries ranging from 97%-102.1%.(2)An electrochemical sensing system based on the three-dimensional Mo S2 nanoflowers prepared with polypyrrole as template.It was applid to detect bisphenol A.Polypyrrole(PPY)was used as a soft template for Mo S2 in the experiment to provide a substrate for the growth of Mo S2.The Mo S2 nanoflowers prepared by this method exhibit a stretched morphology and the petals are large and thin compared with which prepared without polypyrrole.Moreover,it has larger superficial area,more effective edge active sites and defects and the conductivity of modified electrodes has been significantly improved.In the application of bisphenol A detection,a linear range of 1.5-20 μM and a detection limit(3S/N)of 0.5 μM are exhibited.Moreover,the method also showed good anti-interference ability,repeatability and stability.And it can also be used to detect BPA in the real water samples,with the recovery of 95%~102%.