The Study Of Nanomaterials In The Electrochemical Nonenzymatic Glucose Biosensors Based On Bio-carbon Materials

In recent years,the bio-carbon materials from animals or plants have been widely applied in supercapacitor,lithium ion batteries,biosensors and so on.This is owing to the bio-carbon materials which has the merits of nature nanostructure,the excellent magnifications,the inflexible performance,environmentally friendly and cheaply and easily to be obtained.In biosensors,the electrodes made by these composite materials have been payed attention to the researchers.In this thesis,how to increase the electrochemical performance in nonenzymatic glucose sensors is the main study of our research.Meanwhile,we have used the 3D nanostructures obtained from the rose or hemp as the substrate,the Co-based transitional metal sulfides or double transitional metal oxides as the catalytic electro-active materials to do the electrochemical tests.The concrete content of this thesis are as follows:1.A 3D interconnected porous carbon skeleton derived from rose has been obtained through peeling off,freezing-drying and annealing.Then the nanoflower-like CoS has been synthesized by a facial one-pot solvothermal synthetic process.Based on the 3D interconnected porous carbon skeleton of rose offering amount of channels for the transfer of electronic and ions,and the nanoflower-like CoS offering enough electrochemical catalytic active sites to further increase the catalysis of the oxidation of glucose,the electrode performs an excellent electrochemical performance in nonenzymatic glucose sensor.Through amperometric,it has a high sensitivity(697 ?A mM-1 cm-2),low detection limit(2?M)and good anti-interference.2.An innovative carbon nanotube@hemp fiber(CNT@HF)composite has been synthesized and used as a substrate electrode material.Cobalt disulfide nanoparticles(CoS2NPS)have been uniformly decorated on the substrate by one-step hydrothermal route to form an integrated CoS2NPs@CNT@HF nanocomposite electrode.On one hand,the HF and CNT are used to improve the electroconductivity through the synergistic effect;on the other hand,the CNT also can enhance the stability of the electrode as the supporting matrix.In the nonenzymatic glucose sensors,the integrated electrode performs a good electrochemical performance,because it can avoid to decrease the sensitivity which can be restricted by physical methods(such as the dropping off from the electrode,the binder interfaces and so on)and it also can reduce the low detection limit.Through amperometric,it exhibits a broad detection range from 5 ?M to 170?pM,with a sensitivity of 2824 ?A mM-1 cm-2;another wide window from 170 ?M to 1470?M with a sensitivity of 1452 ?A mM-1 cm-2,and a low detection limit of 0.3 ?M.In the human serum tests,the sensor has a satisfactory results.3.We continue to take the HF as the substrate to synthesis the catalytic electro-active species.As each nanowire that connected to the substrate directly is not only the catalytic active species,but also is the channels for the transfer of electronics and ions,the NiCo2O4 nanowires has been synthesized by one-step hydrothermal route on the HF.However,there has a problem need to be solved based on the bad dynamic reaction and the slow transfer of electronics and ions in the solution.Therefore,Ni(OH)2 nanosheets have been electrodeposited on the NiCo2O4 nanowires to form a shell to enhance the stability of the electrode.These composite materials with the core-shell structure can make the electronics and ions transfer fast in the solution,resulting in improving the sensitivity and reducing the low detection limits.Based on the synergistic effect of the core-shell structure,the material is firstly applied in nonenzymatic glucose sensor and performs a good electrochemical behavior(such as a high sensitivity,a low detection limit,a good stability and so on).In summary,the bio-carbon materials from rose or hemp are regarded as the substrates to enhance the conductivity and stability of the electrodes.And the Co-based transitional metal sulfides or double transitional metal oxides are regarded as the catalytic electro-active materials.In nonenzymatic glucose sensor,the electrodes made by these composite materials perform good electrochemical performance(such as high sensitivity,low detection,good stability)and have a satisfactory results in human serum tests.