Non-enzymatic Glucose Sensors Based On Au_XCu_Y Alloy Nanoparticles

The accurate and rapid detection of glucose is of great value in clinical medicine,food and drug production and fermentation.Glucose detection methods involve DNS colorimetry,film titration,high performance liquid chromatography and electrochemical sensor method.Among them,the non-enzymatic electrochemical sensor is the most rapid method of detecting application.The rapid advancement in nanoscience has advanced innovative approaches for the development of non-enzymatic glucose sensors.Massive nanostructured electrocatalysts such as metals,bimetallic alloy and carbon-based nanomaterials were chosen to study and develop as non-enzymatic glucose sensors.These nanomaterials in glucose oxidation has established as a significant tool in non-enzymatic glucose sensor due to high effective surface area.In this paper,the mechanism of enhancing sensor performance was investigated through analyzing the composition and surface texture of as-prepared Au_XCu_Y alloy nanoparticles.Spherical Au₃Cu₁ nanoparticles had been prepared through one-step reduction in one pot at room temperature.The structure,size and composition of Au₃Cu₁ nanoparticles were characterized using transmission electron microscopy?TEM?and high-resolution transmission electron microscopy?HRTEM?.Electrochemical methods were used in characterizing the catalytic performance of Au₃Cu₁ alloy nanoparticles with glucose.HRTEM demonstrated that the Au₃Cu₁ alloy nanocrystals contained a high density of crystal defects.Au₃Cu₁ alloy nanocrystals enriched with various crystal defects,including dislocations and stacking faults,were obtained.The surface structures of the Au3Cu1nanoalloys were important in determining catalytic activity.The results showed that the glucose sensor had a good linear relationship in the range of 1x10^-5-8x10^-33 mol/L with a sensitivity of 56.8?A mM^-1 cm^-2,and the detection limit was 0.67?mol/L?S/N=3?.The glucose sensor showed anti-interference performance toward ascorbic acid?AA?,uric acid?UA?,and fructose?Fru?,with good stability and reproducibility.Branches of Au₃Cu₁ alloy nanocrystals was developed by changing synthetic method.Au3Cu1 alloy nanocrystals had high-indexed facets?HIFs?and twinning through analyzing.Contrast with chapter one,the non-enzymatic glucose sensor based on Au₃Cu₁ alloy nanocrystals showed enhanced sensitivity of 131.3?A mM^-1 cm^-2,a detection limit 0.091?mol/L?S/N=3?.The HIFs and synergistic effect between Au and Cu were key factors of enhancement of sensor performance.The non-enzymatic glucose sensor of Au₂Pt₁Cu₁ ternary alloy nanoparticles was prepared by changing composition.The results showed that the Au₂Pt₁Cu₁ presented surface defect of five fold axis.Compared with the preceding chapter,the prepared Au₂Pt₁Cu₁ enzyme-free glucose sensor displayed:sensitivity of 116?A mM^-1 cm^-2,detection limit of 0.36?mol/L and good selectivity.The Au₂Pt₁Cu₁ ternary alloy nanoparticles is promising for the future development of non-enzymatic glucose sensors in the neutral medium.