Chitosan Stabilized Gold Nanoparticle‐Modified Au Electrodes for the Determination of Polyphenol Index in Wines: a Preliminary Study

Abstract

Gold‐chitosan nanocomposite is successfully proposed for assembling a sensitive and selective electrochemical sensor for the determination of an antioxidant such as caffeic acid, which has recently attracted much attention due to its benefits on human health. In this paper, taking advantage of the peculiar sensing performance of the nanocomposite, an analytical method based on differential pulse voltammetry for determination of polyphenol index in wines was proposed.

Water-soluble acetylated chitosan-stabilized gold nanosphere bioprobes

“…The limit of detection (LOD) and the limit of quantification (LOQ) for melamine and uric acid were obtained by using equations LOD ¼ 3s x/y /b and LOQ ¼ 10s x/y /b where s y/x and b are the estimated standard deviation and the slope of the analytical calibration function of each substance, respectively, with a 95% (degrees of freedom ¼ 3) confidence level [8].…”

Phenothiazine‐Capped Gold Nanoparticles: Photochemically Assisted Synthesis and Application in Electrosensing of Phosphate Ions

“…The majority of modified AuNP interfaces are based on the affinity between thiols and gold (i.e. [28][29][30] The PTZH-AuNP-modified electrode did not show any redox peaks in the potential window À0.4 to +0.5 V versus Ag/AgCl in the blank sample. [15][16]28] Cyclic voltammetric responses of the polycrystalline Au electrode and the electrode modified with PTZH-AuNPs were examined by using 0.1 mm FeðCNÞ 4À=3À 6 in tris buffer solution.…”

Determination of antioxidant activities in fruit juices based on rapid colorimetric measurement and characterisation of gold nanoparticles

“…Plants (such as tea) and fruits or fruit juices are natural sources of antioxidants. Since the antioxidant composition and the matrix varies [5][6][7], a diverse array of analytical methodologies is required to measure antioxidant activities and reducing power [8][9][10][11][12][13][14]. Several common assays such as the ferric-reducing antioxidant power assay (FRAP) [8,9], the cupric-reducing antioxidant capacity (CUPRAC) assay [10,11], the Folin-Ciocalteu method (FC) [5,[12][13][14][15][16][17] and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay [12,15,16] were used to measure total antioxidant activity/capacity or reducing power of tested foods.…”