Preparation Of Nanomaterials By Template Method And Their Application In Electrochemical Sensing

Electrochemical analysis is a rapid,highly sensitive,and accurate analytical method,It is widely used in drug analysis,food safety,clinical testing,and environmental monitoring because of its simple,easy to operate,and time-saving.The preparation of electrode materials is very important for electrochemical sensors.The development and application of novel nanomaterials make it possible to further expand the application range of sensors and increase the sensitivity of sensors.The specific works are as follows:(1)Nano porous gold(NPG)was established by electrodeposition method,and the method of determining trace As3+ by NPG modified electrode was established.Electrochemical characterization of the NPG electrode was carried out to optimize the deposition time,enrichment time,supporting electrolyte and pH.The results showed that the response current value was in good linear relation with the concentration of As3+ in the range of 0.004-4 ?g/mL.The linear equation was y=14.4797x+0.3081(r=0.9985),and the lower limit was 0.004 ?g/mL,The repeatability and reproducibility was investigated with a RSD of 2.41%(n =6)and 3.11%(n =6).The proposed method is simple,sensitive and fast,and has good repeatability and reproducibility.(2)A method was developed to fabricate gold/copper sulfide hollow nanospheres using Cu2O nanoparticles as sacrificial template.Gold/copper sulfide hollow nanospheres has large specific surface area,strong adsorption capacity and good electrocatalytic properties which can significantly enhance the electrochemical signal of the sensor.The electrochemical sensor based on gold/copper sulfide hollow nanospheres for determing hydrogen peroxide was constructed.The potential,the amount of gold/copper sulfide hollow nanospheres,and pH were optimized.Under the optimized experimental conditions the response current with the concentration of hydrogen peroxide is in a linear range of 0.02 to 8 mM and the detection limit is 20 ?M.The linear equation is y= 16.4137x-0.9270(r=0.9979).The repeatability and reproducibility was investigated with a RSD of 2.30%(n =6)and 1.64%(n =6).The proposed sensor presented some advantages including fast response,wide linear range,low detection limit,good reproducility and stability.(3)Palladium nanoparticles was synthesized firstly.Seed growth method was used to synthesis Pd@PtCo core-shell nanoparticles with palladium nanoparticles as seed,PVP as protective agent,hydrazine hydrate as reducing agent.The excellent electrocatalytic activity and efficient electron transport property of Pd@PtCo core-shell nanoparticles was used to construct a non-enzymatic H2O2 sensor.Under the optimized experimental conditions the response current with the concentration of hydrogen peroxide is in a linear range of 0.001 to 6 mM and the detection limit is 1 ?M.The linear equation is y=18.3827x+2.1154(r=0.9988).The repeatability and reproducibility was investigated with a RSD of 1.08%(n =6)and 1.38%(n =6).The proposed sensor presented some advantages including high sensitivity and selectivity,improved stability and fast amperometric response.