Mesoporous N-doped Carbon Nanowall Arrays Modified Carbon Fiber Nanohybrid Microelectrode For Electrochemical Sensing

The yearly cancer death rate for human being over the past few decades has not significantly decreased despite the emergence of new drugs and surgical techniques.One of the reason for this worse picture is that even with the current state of advanced medical technology,However,the primary tumor has metastasized and invaded other organs when we were diagnosed.Therefore,in order to improve the survival rate of cancer treatment,some important issues must be addressed: fabrication of novel electrode for diagnosis of this disease at an earlier.Electrochemical biosensor with its high sensitivity,good selectivity,excellent stability rapid detection as well as superior reproducibility,Which has outstanding performance and wide application prospect in the sensitive detection of cancer markers.Thus,we reported the preparation of a new type of nanohybrid microelectrode based on 3D honeycomb–like with Ni NPs embedded mesoporous N–doped carbon nanowall arrays?MNCNWAs?and a novel microelectrode based on Pt Pd alloy nanoparticles?alloy nanoparticles,ANPs?by using hydrogen reduction,uniformly and densely decorated MNCNWAs wrapped CF improves the sensitivity of the electrode,used in the electrochemical detection of active oxygen free radicals H₂O₂ cancer markers.The main contents of this work are as follows:?1?3D honeycomb–like Ni nanoparticles embedded mesoporous N–doped carbon nanowall arrays wrapped carbon fiber: Flexible microelectrode for electrochemical analysis of biological samplesWe used hydrophilic CF as the substrate,Ni?OH?₂–NSAs as the sacrificial template and DA as carbon and nitrogen sources.The sacrificial template of carbon film with a certain thickness can be prepared by regulating the concentration of DA and the time of self–polymerized,and then the sacrificial template of wrapped PDA?CF@Ni?OH?₂–NSAs@PDA?were placed in the high temperature argon tube furnace for annealing.The purpose that is PDA converted from amorphous carbon to crystalline carbon and Ni?OH?₂ changed Ni NPs under high temperature with carbon sources.Then,a new type of nanohybrid microelectrode based on 3D honeycomb–like Ni NPs embedded mesoporous N–doped carbon nanowall arrays wrapped CF can be constructed after calcination of PDAlayer and removing the Ni?OH?₂–NSAs template.Owing to the synergistic effect of the structural and catalytic properties of different components,the resultant nanohybrid microelectrode exhibits high electrocatalytic activity toward H₂O₂ oxidation.The practical application of the proposed microelectrode has been explored in sensitive detection of biomarker H₂O₂ in human body fluid?plasma,urine?and live cell samples.?2?Ultramicro Pt Pd Alloy Nanoparticles in situ growth on 3D carbon nanowall arrays wrapped carbon fiber for research on the electrochemical sensing system of cancer cells.On the basis of the above work,in this paper,it is easy to get without Ni NPs embedded3 D honeycomb–like Carbon Nano Wall Arrays via increased the time and temperature of calcination of PDA etched by HCl solution.Then,the excellent catalytic performance of precious metal PtPd ANPs to H₂O₂ combine the advantages of MNCNWAs with good conductivity,high stability and large specific surface area,successfully fabricating ultramicro PtPd ANPs uniformly distributed in the MNCNWAs by impregnated the CF@MNCNWAs in Pt and Pd precursor mixed solution,The hydrogen reduction method was used to synthesize ultramicro PtPd ANPs on the carbon nanowall arrays.The dispersion,load and stability of PtPd ANPs were improved by using MNCNWAs with good conductivity,high stability and large specific surface area.Due to the excellent catalytic performance of the precious metal PtPd ANPs for H₂O₂,the sensitivity of the modified microelectrode to detect H₂O₂ was significantly improved.The microelectrode CF@PtPd ANPs–MNCNWAs was used to detect cervical cancer cells?Hela?,human hepatocellular carcinoma?Hep G2?and human breast cancer cells?MCF–7?.According to the different types of cancer cells release different contents of H₂O₂ under the same stimulation,thus,this microelectrode can be sensitive differentiation of different cancerous cells as well as distinguish between cancer cells and normal cells,which is of great clinic significance for cancer diagnosis and identification of cancer cells.