Construction And Performance Study Of A Novel Bioelectrochemical Hydrogen Peroxide Sensor

In recent years,the demand for hydrogen peroxide(H2O2)detection in food analy-sis,medical testing,engineering control,environmental protection and other fields has been continuously increasing.It is of great importance to develop highly efficient,fast,high-sensitivity,low-cost H2O2 sensors.In this article,a new type of H2O2 sensor is constructed based on the microbial fuel cell(MFC)technology in the bioelectrochemcal system.Graphite electrodes(GE)and nano-CoMn2O4@GE graphite are used as the cathode materials respectively to study the performance of the sensor.The article ana-lyzes and compares the electrochemical performance of different cathode materials,op-timizes the operating parameters of th sensor,tests the sensor's sensitivity and reliability and studies the influence of environmental disturbance factors on the sensor perfor-mance.The experiment draws the following conclusions:(1)The H2O2 sensor constructs with GE as the cathode material,and is equipped with an anion exchange membrane or a cation exchange membrane(AEM,CEM),re-spectively.The optimal sensor operating conditions is pH 7.0,at a flow rate of 5 mL min-1 with external resistance 500 or 300 2.When using different ion exchange mem-branes,there are good exponential relationships between the response current and the logarithm of H2O2 concentration,the sensitivity can up to 156.7 ?A mM-1.The selectiv-ity and stability of the sensor are well.Compared with the anion exchange membrane,the sensor with cation exchange membrane has a higher response current,and under the same conditions,the response current can be 33%higher than the sensor with the anion exchange membrane.(2)CoMn2O4@GE can promote ion and electron migration and enhance sensor sensitivity.The H2O2 sensor constructs with CoMn2O4@GE as the cathode material,and is equipped with a cation exchange membrane(CEM).The optimal sensor operat-ing conditions is pH 7.0,at a flow rate of 5 mL min-1 with external resistance 500 or 300 ?.There is a good linear correlation between the sensor response current and the logarithm of H2O2 concentration,the sensitivity can up to 6.9 ?A mM-1.The selectivity and stability of the sensor are well,and superior to the GE cathode H2O2 sensor.(3)Environmental disturbance factors study found that the presence of organic matter or the change of temperature has little effect on the performance of the device,however,as the concentration of dissolved oxygen or Fe2+ in the catholyte increases,the sensor current output increases.