| Gold nanoparticles-modifide electrode was prepared by applying a seed mediated growth method in this thesis, and this modified electrode was charactered by electrochemical methods.The electrochemical behavior of NO2- , ascorbic acid (AA) and uric acid (UA) was studied. The L-Cystein SAMs (Au/GCE SAMs) were prepared on nanopartilce-modified electrode and charactered by cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) electrochemical technology. Furthermore, the electro-catalystic activity of the L-Cystein SAMs to AA and UA were investigated.The main contents are listed as follows:A new type of gold nanoparticles-attached glassy carbon electrode was fabricated by applying a seed mediated growth method, without using peculiar binder molecules. The surface coverage of gold nanoparticles on glassy carbon electrode was calculated as 5.4×10-10mol?cm-2. Furthermore, the Au/GC electrode exhibited a relatively low electron transfer resistance for aqueous redox couples than the Au/L-Cys/GC electrode. The behavior of NO2– on the nanogold modified electrode was studied. The result showed that compared with the bare glassy carbon electrode, the oxidation peak of NO2 - on this Au/GC electrode shifted negatively 198mV accompanied with an enhancement of 1.66μA in oxidation peak current. It instructed that nanoparticle gold had obviously catalysis to NO2 - .The anodic current of NO2- is linearly proportional to NO2- concentration from 1×10-55×10-3mol?L-1 with a correlation coefficient of 0.9998.The linear equation is expressed as ip a( A) = 5.621×1 0? 7 + 2.222×1 0? 2 C( m ol iL ?1), it means that this modified electrode can be used to detect the quantity of NO2 - in water .The L-Cystein SAMs on nanoparticle gold modified electrode was constructed and this monolayer was characterized by CV and EIS techniques. The results instructed that the monolayer can counteract the reaction of[Fe(CN)6] 3-/[Fe(CN)6]4-.The electro-catalystic activity to biomolecules such as uric acid and ascorbic acid of the modified electrode was also studied. The oxidation peaks of uric acid and ascorbic acid could be separated to 211mV implying that the uric acid and ascorbic acid can be detected simultaneity at this L-Cys/Au/GC electrode. The anodic current of UA is linearly proportional to UA concentration from 2×10-61×10-3molL-1 with a correlation coefficient of 0.9993.The linear equation is expressed as ip a( A) =1 .584×1 0- 7 +1 .005×1 0 5 C ( m oli L1).The anodic current of AA is also linearly proportional to AA concentration from 2×10-6 8×10-4molL-1 with a correlation coefficient of 0.9969.The linear equation is expressed as ip a(A) =2 .213×1 0-7 +1 .566×1 0-7 C (m oli L1)... |
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