Electrochemical Preparations Of Gold Nanostructured Materials And Their Electrochemical Detection Of Ascorbic Acid

Gold nanostructured materials have been widely applied in nonenzymatic sensors,electrocatalytic water splitting,superhydrophobic surface,surface-enhanced Raman spectroscopy?SERS?,photoelectrochemical solar cells,and so on.Among many methods for preparing gold nanomaterials,the electrochemical method has the advantages of simple,mild,cheap,controllable,et al.In this paper,gold nanostructured materials were prepared by electrochemical method and used for constructing nonenzymatic AA sensors.The main contents are as follows:1.This paper introduces the classification,characteristics and preparation methods of nanomaterials,and also of the gold nanoparticles and nanoporous gold.2.Small gold nanoparticles?SGNPs?were prepared by a mild anodic dispersion of gold wire in an acidic solution contained Cl^-and Sn?II?species.The anodic behavior is examined by in situ Raman spectroscopy and the preparation principle is discussed.The SGNPs exhibits high electrocatalytic activity toward ascorbic acid?AA?oxidation and excellent performances in AA sensing with a wide linear range?0.1?M¹3 ?M?,high sensitivity(1044mA ?M^-1 cm^-2),low detection limit?0.06?M?,short-time response?6 s?,good anti-interference,long-term stability?over 24 days?,and satisfactory quantification of AA concentration in medicine vitamin C tablets.3.Nanoporous gold film?NPGF?were prepared by combining anodization of pure gold substrate in H₂SO₄ solution and chemical reduction of gold oxide film with a reducing agent.The dependances of anodic potential,anodic time and kind of reducer on roughness of films were examined.The NPGF exhibited high electrocatalytic activities toward the AA oxidation and excellent performances in sensing AA with a wide linear range?0.1?M⁸ ?M?,high sensitivity(2834mA ?M^-1 cm^-2),low detection limit?0.1?M?,short-time response?3 s?,good anti-interference,and satisfactory quantification of AA concentration in medicine vitamin C tablets.4.A facile,green method was developed to fabricate a three-dimensional?3D?flower-like nanostructured gold film?3D FNGF?by an anodic potential step of pure gold substrate in a KCl and AA mixing solution.The formation of 3D FNGF might be related to four main processes:gold electrodissolution,gold?I?disproportion,chemical reduction of AuC1₄^-,and redeposition of Au NPs.The oxidation potential and time were investigated to obtain the maximum roughness factor.The as-prepared 3D FNGF exhibited high electrocatalytic activities toward the AA oxidation and excellent performances in AA sensing with a wide linear range?0.2?M¹0 ?M?,high sensitivity(2920mA ?M^-1 cm^-2),low detection limit?0.11?M?,short-time response?3 s?,good anti-interference,and satisfactory quantification of AA concentration in medicine vitamin C tablets.