Studies On Non-enzymatic Glucose Sensor With Binary Transition Metal Oxides

Diabetes is one of the most fatal chronic diseases in clinical medicine.High blood glucose concentration in human body will lead to diabetes and even many complications.In recent years,with the increasing number of diabetes patients,developing a fast and accurate glucose detection method has become the focus of researchers.Electrochemical method is widely used in glucose detection due to its advantages of portable,easy operation and high selectivity.The enzyme glucose sensor is expensive and susceptible to the environment?eg:temperature,pH?,which limits its application range.Therefore,people have focused on the development of non-enzymatic electrochemical glucose sensors in recent years.With the rise of nanomaterials,non-enzymatic glucose sensors based on nanomaterials with various structures have also achieved good results with high sensitivity and good selectivity.Transition metals,which are abundant in nature and cheap in price,are widely used as catalysts in various fields.Benefiting from the reaction between the redox electron pairs and the synergistic effect between the mixed valence elements,the bi-transition metal oxides show good catalytic activity towards glucose oxidation.In this paper,we prepared NiCo₂O₄ and CuCo₂O₄ as catalyst in a simple way,and modified the glassy carbon electrode to achieve the purpose of fast and sensitive detection of glucose.The main contents are as follows:?1?NiCo₂O₄ hollow nanocages?NiCo₂O₄ HNCs?were synthesized by using ZIF-67 as the precursor and template through simple solvothermal method and calcining.Owe to the mesoporous structure,abundant active sites and large specific surface NiCo₂O₄ HNCs,the NiCo₂O₄ HNCs modified glassy carbon electrode?NiCo₂O₄ HNCs/GCE?shows high electrochemical catalytic activity for the oxidation of glucose in alkaline medium.The proposed non-enzymatic glucose sensor afforded excellent analytical performances assessed with the aid of cyclic voltammetry and amperometry?i-t?.The experimental results show that the non-enzymatic glucose sensor has high sensitivity,low detection limit,good anti-interference ability and stability.This sensor is proved to be practical by measuring glucose level in human serum.?2?Flower-like MoS₂-CuCo₂O₄ was synthesized via a simple hydrothermal method with molybdenum disulfide?MoS₂?as fixed platform.The introducing of MoS₂ dispersed the easily agglomerated CuCo₂O₄ micro-flower,allowed more exposed active sites,and increased the catalytic activity of CuCo₂O₄ micro-flower towards the oxidation of glucose.In addition,the synergistic effect between MoS₂ and CuCo₂O₄ makes it show good catalytic performance to glucose under alkaline conditions.It was found that MoS₂-CuCo₂O₄ modified glassy carbon electrode?MoS₂-CuCo₂O₄/GCE?had high sensitivity and low detection limit to the detection of glucose.We also evaluated the practicality of MoS₂-CuCo₂O₄/GCE,the results showed the as-prepared enzyme-free glucose sensor had good selectivity,repeatability and reproducibility,and could be applied to the test of real samples.