Research On The Construction And Sensing Response Performance To Heavy Metals Of Bi-based Electrode

Due to their high toxicity,bioaccumulation and non-biodegradability,heavy metals pose a serious threat to living organisms and ecosystems.Therefore,the analysis of heavy metal ions in drinking water and environmental water is very important for human health and environmental monitoring.Compared with other methods,electrochemical analysis technology has the advantages of low cost,small equipment,simple operation,time saving,and low detection limit.The miniaturization,high sensitivity,and satisfactory reliability of electrochemical sensors have always been the focus of the field of electrochemical analysis.In view of this,this article uses conductive polymers and nanomaterials as the substrate,combined with the method of in-situ electrodeposition of bismuth film to construct the first electrochemical sensor.Then,the second type of electrochemical sensor was constructed using the method of ex-situ electrodeposition of bismuth film.Research on heavy metal ion sensors based on nanomaterials and bismuth has been carried out.The work content of this article mainly includes the following four parts:（1）Firstly,the AuNPs/PANI composite material was loaded on a screen-printed gold electrode（SPAuE）,and the results of scanning electron microscopy and X-ray diffraction characterization showed that the prepared AuNPs/PANI/SPAuE electrodes with reticulated fiber-like PANI and well-dispersed AuNPs were successfully prepared.Then,the in-situ Bi FE and AuNPs/PANI/SPAuE electrodes are combined to construct an ultra-sensitive Bi@AuNPs/PANI/SPAuE electrochemical sensor.（2）The influence of the electrodeposition potential of bismuth in 0.2 M bismuth bath on the morphology of the bismuth film and the influence of the electrodeposition potential and the electrodeposition time on the electrochemical performance are explored.The best bismuth electrodeposition conditions are determined through SEM,XRD characterization and electrochemical testing,successfully constructed Bi/SPAuE_-0.08V sensor with high performance and high reliability.（3）The sensing research and performance research of the constructed Bi@AuNPs/PANI/SPAuE sensor were studied by square wave anodic stripping voltammetry（SWASV）.The results show that Bi@AuNPs/PANI/SPAuE can simultaneously detect the three heavy metal ions（Cu（II）,Pb（II）and Cd（II））,and obtains good linearity in the concentration range of 0～200μg L^-1（R²>0.99）,the detection limits were 0.13μg L^-1,0.06μg L^-1 and 0.09μg L^-1,respectively.In addition,the anti-interference,repeatability,reproducibility and stability of the constructed electrode were discussed in detail,and the reliability of the proposed method was verified.（4）The sensing research and performance research of the prepared Bi/SPAuE_-0.08Vsensor were studied by SWASV.The results show that the sensor has excellent electrocatalytic ability for Pb（II）,Cd（II）and Zn（II）,and has a wide linear range(1～120μg L^-1).The detection limits were 0.04μg L^-1,0.02μg L^-1 and 0.05μg L^-1（S/N=3）,respectively.In addition,the prepared sensor shows satisfactory anti-interference ability,repeatability,reproducibility and stability.At the same time,the applicability of the proposed method is verified by detecting heavy metal ions in actual samples,so this type of sensor is expected to find practicality in portable heavy metal detection applications.