Free-Standing Cobalt-Based Non-Enzymati Glucose Sensor On The Carbon Cloth Substrate

In recent years,more and more people are troubled by diabetes,a chronic disease.Diabetes can induce a variety of complications.Fortunately,patients can reduce the risk of complications by frequently self-test and control blood sugar.Therefore,accurate and rapid blood glucose detection method is imperative.At present,most of the blood glucose meters on the market are electrochemical sensors.The testing principle is to use the related enzymes existing on the test paper that can catalyze the oxidation of glucose and react with the glucose in human blood sample for detection.However,due to the fact that the biological enzyme is easily affected by the external environment,the method has certain limitations,so researchers devote more energy to enzyme-free research on glucose sensor.Enzyme free glucose electrochemical sensor uses non enzyme material instead of enzyme to directly catalyze the oxidation of glucose.Its working electrode can be divided into two types: chemically modified electrode and self-supporting electrode.The self-supporting electrode avoids the influence of the process of adding binder on the performance of the electrode,and can improve the stability and reproducibility of the electrode.The research work of this paper is based on self-supporting electrode.Among the non-enzymatic materials?many metals and their compounds?,cobalt based compounds with cobalt ion as the center have excellent performance in electrocatalytic oxidation of glucose.In this study,cobalt based compounds were directly grown on carbon cloth?CC?to prepare self-supporting Co₃O₄/CC and CoS₂/CC electrode materials,which were used as the working electrodes of enzyme-free glucose sensor,respectively,to explore their detection electrochemical properties of glucose.The results of this study are as follows :In the first part of this paper,Co₃O₄/CC electrode materials were successfully prepared on the carbon cloth substrate through the two preparation steps of potentiostatic deposition and tube furnace calcination,and Co₃O₄ nanoflakes were dense and interlaced on the substrate.When glucose was detected by self-supporting Co₃O₄/CC electrode without enzyme,the linear range is 1 ?mol·L^-1-0.776 mmol·L^-1,the detection limit is 0.33 ?mol·L^-1?signal-to-noise ratio is 3:1?,and the sensitivity is7402.09 ?AmM^-1cm^-2.The material has good selectivity and long-term stability for glucose.On the basis of the first part,the second part of this paper is to prepare self-supporting CoS₂/CC electrode material on carbon cloth by potentiostatic deposition and tubular furnace sulfurization calcination.In the three electrode system,it is used as the working electrode to catalyze the oxidation of glucose.After a series of electrochemical tests,the linear range of glucose detection is 1 ?mol·L^-1-1.067mmol·L^-1,the sensitivity is 2690.7 ?AmM^-1cm^-2,and the detection limit is 0.33?mol·L^-1.In addition,the selectivity,anti-chloride toxicity and long-term stability of the electrode were tested.The results show that the electrode can achieve good selectivity for glucose when the glucose content in the system is 20 times that of the interfering substance;when the concentration of chloride ion is 100 times that of glucose,the detection current of the electrode is almost unaffected,showing strong anti-toxicity.Moreover,it can maintain good electrode stability during the 19 day experimental period.