Research On The Preparation Technology And Sensing Properties Of Nanoporous Gold Based Electrochemical Sensor

Enviromental pollution raised to be a global challenge in recent years.In order to improve the ability to detect environmental pollutants,detecting devices develoment becomes an important task,in which electrochemical sensor is considered to be a proper candidate with great potential due to its low cost,small volume and easy operation.Because of the unique structure and special properties,nanoporous metals have wide applications electrochemical sensors,of which nanoporous gold(NPG)is the most representative.In this work,the technology of preparing nanoporous gold by electrochemical dealloying in a mixed solution of H2SO4 and NaCl was explored.Based on the exploration,different active catalytic materials were loaded on NPG to fabricate different molecular sensing electrodes.The work is mainly composed of the following three parts(1)This work investigates the effects of dealloying parameters on morphology and electrochemical performance of NPG.By adjusting the dealloying potential and the concentration of NaCl in the corrosive solution,a series of nanoporous gold was prepared.After being systematically tested(SEM,XRD and electrochemica tests),the optimal process parameters of NPG were determined(2)A standard integrated three-electrode sensor device(SITE)modified with palladium nanoparticles and nanoporous gold(Pd/NPG-SITEs)was designed for 4-aminophenol(4-AP)and paracetamol(PAR)determination.For 4-AP,the sensitivity is 0.58 ?A ?M-1,the detection limit reaches 0.13 ?M(S/N=3),the linear range is 2 ?M to 300 ?M.For PAR,the sensitivity is 0.28 ?A ?M-1,the detection limit reaches 0.05 ?M(S/N=3),the linear range is 5 ?M to 600?M.The Pd/NPG-SITEs showed good anti-interference performance,excellent reproducibility and good stability in tests,which is hopeful to be applied in practical determination(3)A NPG film modified with palladium-cerium dioxide composite(Pd@CeO2)was successfully prepared on a carbon paper substrate(Pd@CeO2/NPG/CFP).The electrode showed excellent sensing performance toward 4-aminophenol(4-AP)determination.The sensitivity is extremely as 75 ?A ?M-1,and the detection limit is as low as 4 nM(S/N=3)and the linear concentration range is 0.03 ?M to 9 ?M.Meanwhile,the Pd@CeO2/NPG/CFP also showed excellent repeatability and stability,which is very helpful to extended the electrode to practical applications.