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Electrochemical Sensors Based On Metal Nanoparticles Modiifed Electrode

Posted on:2013-01-10Degree:MasterType:Thesis
Country:ChinaCandidate:X X LinFull Text:PDF
GTID:2248330374490698Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
In recent years, the use of nanostructured materials for catalysis and analysis is anextremely promising prospect. Due to the small size effect, the surface effect,thequantum effect and the macroscopic quantum tunnel effect, nanoparticles showexcellent physical, chemistry and electrochemical properties. People are paying moreand more attention to the preparation of electrochemical sensors based on metalnanoparticles. In this paperwe use dispending method, seed-mediated method andelectrochemical deposition method respectively to build several new types ofelectrochemical sensing interface. The prepared sensors have the advantages of simplefabrication and good performance and can realize the determinations of targets. Thedetails are summarized as follows:(1) In chapter2, the glassy carbon electrode was modified with gold nanoparticlesthrough dispending method. The electrocatalytical behaviors of the modified electrodetowards phenol were investigated by CV. The results revealed that this AuNPs/GCEshowed a strong electrocatalytic ability for the redox of phenol. Under optimalconditions, the peak current of phenol was linear to its concentration from6.3×10-5mgmL-1to54mg mL-1with a detection limit of6.3×10-5mg mL-1. This sensor is initiallyused for the detection of phenol in the wastewater.(2) In chapter3, for the first time, copper nanoparticles (CuNPs) were prepared byseed-mediated growth method using3.5nm gold nanoparticles (AuNPs) as seeds andcarbon nanotubes (CNTs) as growth scaffold. A CuNPs/CNT modified electrodesurface was constructed successfully. The modified electrode showed goodelectrochemical activity for electrocatalytic oxidation of glucose in alkaline medium,which was utilized as the fabrication of a nonenzymatic biosensor for electrochemicaldetection of glucose. The biosensor in optimal conditions had a linear range of1.0×10-7M to5×10-3M for glucose detection with a detection limit of3×10-8M.(3) In chapter4, platinum nanoparticles were electrochemically deposited on agold-nanoporous film coated gold electrode to prepare a sensor for determingformaldehyde. Gold-nanoporous film was obtained by anodizing the gold electrodeunder a high potential and then reduced by freshly prepared ascorbic acid(AA) solution.The electrochemical behaviors of formaldehyde at the sensing surface were studied bycyclic voltammetry. The results showed that this Pt-nanoparticle-coatedgold-nanoporous film (PGNF) electrode had a good electrocatalytic ability for the redox of formaldehyde in acidic medium. Under optimal conditions, the peak current offormaldehyde was linear to its concentration from1×10-5M to1×10-3M with adetection limit of5×10-6M.
Keywords/Search Tags:Electrochemical sensors, Metal nanoparticles, Dispending method, Seed-mediated method, Electrochemical deposition method
PDF Full Text Request
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