Free-Standing Nickel/Cobalt-Based Non-Enzymatic Glucose Sensor On The Carbon Paper Substrate

Glucose is not only an indispensable substance in the life process,but also an important raw material in food,brewing,medicine and other production industries.In addition,the number of bacteria proliferation and metabolism in the fermentation process will be directly affected by the concentration of glucose.It’s very important to detect the content of glucose quickly and accurately.Electrochemical sensors have the detection characteristics of simple operation,rapidity,portability and accuracy,and have attracted much attention in the detection of glucose content.In this paper,the carbon fiber was used as the conductive matrix and transition metal compounds as the electrochemically active materials,nickel-cobalt-based transition metal composite materials with different morphologies were prepared to established non-enzymatic glucose sensor.The specific contents are as follows:（1）This study that enables high sensitivity,wide linear enzyme-free detection of glucose at low concentrations using in situ growth of conductive nickel/cobalt carbonates on carbon paper（Ni/Co CNs/CP）via a facile one-step hydrothermal method.Scanning electron microscope（SEM）,X-ray diffraction（XRD）,and X-ray spectrometry Photo-electron spectroscopy（XPS）were used to characterize the morphology and phase composition of Ni/Co CNs.The resulting Ni/Co CNs exhibited high performance in the non-enzymatic glucose determination because of their large surface area and the presence of active catalytic sites.Under optimised conditions,their sensitivity can reach up to 1442μAmM^-1cm^-2,their linear range covers four orders of magnitude from 0.45 to 2273μM and they exhibit a fast response time of 3.5s and a low detection limit of 0.15μM（S/N=3）.Furthermore,the developed biosensor showed outstanding selectivity,good stability and uncomplicated reproducibility for glucose detection,demonstrating that Ni/Co CNs/CP is a promising electrode for non-enzymatic glucose sensing.（2）The non-enzymatic glucose sensor was prepared by using in situ growth of nanoscale nickel/cobalt carbonate hydroxide（Ni/Co CHs）nanorods on carbon paper（Ni/Co CHs/CP）via a facile one-step hydrothermal method.Scanning electron microscope（SEM）,and X-ray diffraction（XRD）were used to characterize the morphology and phase composition of Ni/Co CHs.The resulting Ni/Co CHs nanorods has a shorter electron transmission path,while the synergy between nickel and cobalt increases the electron transfer rate.Cyclic voltammetry（CV）and chronoamperometry studies displayed that Ni/Co CHs nanorods exhibited high performance in the non-enzymatic glucose sensing.The sensor with high sensitivity can reach up to 1817μAmM^-1cm^-2,wide linear range from 4.2 to 2623 μM,a fast response time of 5 s and a low detection limit of 1.4μM（S/N=3）,good selectivity and repeatability.