Determination of dipyridamole using TCPO-H2O2 chemiluminescence in the presence of silver nanoparticles

Curcumin-Based Molecularly Imprinted Polymer Electropolymerized on Single-Use Graphite Electrode for Dipyridamole Analysis

A new molecularly imprinted polymer (MIP)-based disposable electrochemical sensor for dipyridamole (DIP) determination was obtained. The sensor was rapidly prepared by potentiodynamic electrochemical polymerization on a pencil graphite electrode (PGE) using curcumin (CUR) as a functional monomer and DIP as a template molecule. After the optimization of the conditions (pH, monomer-template ratio, scan rate, number of cyclic voltammetric cycles applied in the electro-polymerization process and extraction time of the template molecule) for MIP formation, DIP voltammetric behavior at the modified electrode (MIP_PGE) was investigated. DIP oxidation took place in a pH-dependent, irreversible mixed diffusion-adsorption controlled process. Differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV) were used to quantify DIP from pharmaceutical and tap water samples. Under optimized conditions (Britton-Robinson buffer at pH = 3.29), the obtained linear ranges were 5.00 × 10-8-1.00 × 10-5 mol/L and 5.00 × 10-9-1.00 × 10-7 mol/L DIP for DPV and AdSDPV, respectively. The limits of detection of the methods were 1.47 × 10-8 mol/L for DPV and 3.96 × 10-9 mol/L DIP for AdSDPV.

Optical sensors based on silver nanoparticles for determination of pharmaceuticals: An overview of advances in the last decade

This review focuses on optical nanosensors based on silver nanoparticles (Ag NPs) and demonstrates their applications in the determination of pharmaceutical compounds in the last decade. Such optical sensors have received high attention in the analytical field owing to their low cost and simplicity since they do not require any complex or expensive instrumentation. This article reviews Ag NP-based optical methods for the determination of pharmaceutical compounds from 2010 to 2020. The reported optical methods are classified into four types: spectrophotometry, spectrofluorimetry, scattering and chemiluminescence. Ag NPs play different roles in the different sensing platforms used by these methods, the details of which are carefully explained in this review. Moreover, the relevant analytical parameters of the developed methods are categorized by role and tabulated. It is hoped that this review will stimulate further research in this field with similar nanostructures.

Silver nanoparticles enhanced a novel TCPO-H₂O₂-safranin O chemiluminescence system for determination of 6-mercaptopurine

The present study deals with first attempt to introduce safranin O as the fluorophore for peroxyoxalate chemiluminescence system. The reaction of bis-(2,4,6-trichlorophenyl) oxalate (TCPO) with H2O2 catalyzed by silver nanoparticles can transfer energy to safranin O via the formation of dioxetanedione intermediate and emits orange-red light. The relationship between CL intensity and the concentration of TCPO, fluorophore, hydrogen peroxide and nanocatalyst was investigated. The Ag nanoparticles were synthesized by chemical reduction method and characterized using scanning electron microscopy, particle size analyzer and UV-spectroscopy. Moreover, the system was applied successfully to detect a drug, 6-mercaptopurine (6-MP) in pharmaceuticals. Under optimum conditions, a linear working range for 6-MP concentrations from 5.5 × 10(-7) to 5.5 × 10(-5)mol L(-1) (r>0.9831, n=6) was obtained with a detection limit of 1.6 × 10(-7)mol L(-1). The relative standard deviation for 6 repetitive determinations was less than 3.8% and recoveries of 98% and 103% were obtained.