基于双链DNA的苯酚传感器的研究

Study on Phenol Sensor Based on Double Stranded DNA

首先在玻碳电极(GCE)表面电聚合硫堇,得到聚硫堇修饰玻碳电极(PTh/GCE),然后在PTh/GCE上依次电沉积普鲁士蓝-金纳米复合物(PB-Au)和金纳米粒子(GNPs),最后利用滴涂法固定双链DNA,制备一种基于双链DNA的苯酚传感器(dsDNA/GNPs/PB-Au/PTh/GCE).利用循环伏安法和电化学交流阻抗技术对传感器的制备过程进行了表征,研究了亚甲基蓝(MB)和[Fe(CN)_6]^(3-/4-)的协同指示剂作用,测试了苯酚传感器的响应性能,考查了传感器的一致性和抗干扰能力,最后对某制药厂的含酚废水进行了检测.结果表明,在1×10^(-3)~1×10^(-8)mol/L范围内,MB峰电流与苯酚浓度呈现良好的线性关系,相关系数为0.995 8,检出限为2.36×10^(-13)mol/L,该传感器一致性好,并具有一定的抗干扰能力,在环境监测领域具有广阔的应用前景.

An electrochemical phenol sensor based on the double stranded DNA is designed and prepared.The polythionine modified glassy carbon electrode （PTh/GCE） is prepared by electrochemical polymerization of thionine.Then the Prussian blue-gold nanocomposite （PB-Au） and gold nanoparticles （GNPs） is successively electrodeposited on the PTh/GCE surface.Finally,the double stranded DNA is fixed on the electrode surface by drop-coating method.A phenol sensor （dsDNA/GNPs/PB-Au/PTh/GCE） is fabricated.The preparation process of the sensor is characterized by cyclic voltammetry and electrochemical impedance spectroscopy.The synergistic effect of methylene blue （MB） and [Fe（CN）6]3-/4- is studied.The response of the sensor to phenol is tested.In addition,the consistency and anti-interference of the sensor are investigated.The content of phenol in the wastewater from a pharmaceutical factory is detected.The results show that the sensor has a good linear relationship between the peak current of MB and the concentration of phenol in the range of 1 × 10^-3- 1 × 10^-8mol/L,the correlation coefficient is 0.995 8,the detection limit is 2.36 × 10^-13mol/L.The developed method has many advantages such as low limits of detection,good consistency and strong anti-jamming performance.It has broad application prospects in the field of environmental monitoring.