Delphinidin immobilized on silver nanoparticles for the simultaneous determination of ascorbic acid, noradrenalin, uric acid, and tryptophan

Abstract

In the present study, the fabrication of a new modified electrode for electrocatalytic oxidation of noradrenalin, based on the delphinidin immobilized on silver nanoparticles modified glassy carbon electrode. Cyclic voltammetry was used to investigate the redox properties of this modified electrode. The surface charge transfer rate constant (k) and the charge transfer coefficient (α) for the electron transfer between the glassy carbon electrode and the immobilized delphinidin were calculated. The differential pulse voltammetry exhibited two linear dynamic ranges and a detection limit of 0.40μM for noradrenalin determination. Moreover, the present electrode could separate the oxidation peak potentials of ascorbic acid, noradrenalin, uric acid, and tryptophan in a mixture. The usefulness of this nanosensor was also investigated for the determination of ascorbic acid, noradrenalin, and uric acid in pharmaceutical and biological fluid samples with satisfactory results.

Determination of Antioxidant Activity by Oxygen Radical Absorbance Capacity (ORAC-FL), Cellular Antioxidant Activity (CAA), Electrochemical and Microbiological Analyses of Silver Nanoparticles Using the Aqueous Leaf Extract of Solanum mammosum L.

“…35 Most studies that measure antioxidant activity using silver nanoparticles are based on methods such as DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), ABTS (2,2ʹazino-bis [3-ethylbenzothiazoline-6-sulfonic acid]), and FRAP (ferric reducing ability of plasma), among others. 36,37 The technique of oxygen radical absorption capacity using fluorescein (ORAC-FL) 38,39 has been applied very infrequently to analyze the behavior of different nanoparticles, especially using plant extracts, 28,[40][41][42][43] as have electrochemical methods such as differential pulse voltammetry (DPV) and cyclic voltammetry (CV). 36,37 However, all these methods do not accurately reflect the antioxidant capacity at the cellular level, since physiological conditions such as pH, temperature, bioavailability and metabolism are not taken into account, so the use of in vitro models would allow a better approach for the determination of the antioxidant capacity.…”

Multivariate optimization of mebeverine analysis using molecularly imprinted polymer electrochemical sensor based on silver nanoparticles

“…Here, silver NPs (AgNPs) exhibits a good electrocatalytic effect can effectively catalyze the oxidation of MEB are chosen to amplify the electrochemical response because they are easy to functionalize and quite stable in aqueous environment. Among several different methods for preparation of silver nanoparticles such as chemical reduction of silver cation in the presence of stabilizers [ 28 ], layer-by-layer adsorption [ 29 ], template induction [ 30 ], electrodeless preparation [ 31 ], and electrochemical deposition [ 32 ], electrodeposition is a simple, fast and inexpensive method for preparation of metal nanoparticles possessing unique properties such as high purity of the particles, higher control over the dimension and density of particles, lower particle size distribution and a very short time scale compared to other methods [ 33 ]. Thus, in this work, we used a potentiostatic electrodeposition method.…”

Preparation of Multiwalled Carbon Nanotubes: Electrochemically Treated Pencil Graphite Electrodes for Nanomolar Detection of L‐Tryptophan in Complex Samples

“…Serum sample [50] DSNPs-GCE [g] NA [f'] , AA, UA, L-Try DPV 0.40 129.0-330.0 Vitamin C tablet, Injection solution of NA and urine (human) [34] ERGO/CFME [h] L-Try, UA, GSH [g'] Amperometric 0.10 0.60-10.0 10.0-100.0…”