阳极表面积对生物电化学传感器的性能影响研究

Effect of anode surface area on performance of bioelectrochemical sensor

以生物电化学系统(BES)为基础提出了一种BOD水质监测传感器,探究了生物电化学传感器产生的电信号与底物BOD值之间的相关关系,并评估了阳极表面积对其性能的影响。采取循环伏安法(CV)和线性扫描伏安法(LSV)对其生物活性和电子传递能力进行了讨论,并利用微生物多样性分析其阳极界面上的微生物均匀度和丰富度。研究结果表明,完整碳刷和1/2碳刷传感器的最大电流都达到了1.18 mA,而1/4碳刷的只有0.5 mA。完整碳刷和1/2碳刷传感器在不同时间下的BOD-电流拟合曲线的R2值在3 min时高达0.9,1/4碳刷在2 min时,R2值达到了0.9以上。完整碳刷、1/2碳刷和1/4碳刷的负峰电位接近,峰值电流密度逐渐提高。1/2碳刷的微生物菌群分布较为均匀。3种表面积的碳刷阳极都具有较高的传感器性能,其中,1/2碳刷阳极整体利用效率最高。容积为236 mL的BOD监测传感器,利用碳刷作为阳极时,阳极的表面积为1193.13 cm^(2)比较合适。

Based on the bioelectrochemical systems(BES),an water quality monitoring sensor for BOD was proposed.The correlation between electrical signal generated by the sensor and the BOD value in the substrate was investigated;besides,the effect of anode surface area on the performance of bioelectrochemical sensor was evaluated.The bioactivity and electron transport capacity of the said sensor were discussed using cyclic voltammetry(CV)method and linear sweep voltammetry(LSV)method,more than that,the uniformity and richness of the microorganism on the anode interface were analyzed through microbial diversity.The study results showed that,the maximum current of both the complete carbon brush and the 1/2 carbon brush reached 1.18 mA,while the maximum current generated by the 1/4 carbon brush anode was only 0.5 mA.The R2 value of the fitted curve of the BOD-electric current of the complete carbon brush and 1/2 carbon brush sensor at different time reached 0.9 at 3 min,while the R2 value of 1/4 carbon brush reached above 0.9 at 2 min.The negative peak potentials of the complete carbon brush anode,1/2 carbon brush anode and the 1/4 carbon brush anode were close,and the peak electric current density gradually increased.The distribution of microbial flora on the 1/2 carbon brush anode was more uniform.The carbon brush anodes with three different surface areas all had high sensor performance,and the overall utilization efficiency of 1/2 carbon brush anode was the highest.The suitable surface area of the anode was 1193.13 cm^(2) in a 236 mL BOD monitoring sensor using a carbon brush as the anode.