Voltammetric Determination of Droxidopa in the Presence of Tryptophan Using a Nanostructured Base Electrochemical Sensor

Abstract

A novel carbon paste electrode modified with Cu-TiO 2 nanocomposite, 2-(ferrocenylethynyl)fluoren-9-one (2FF) and ionic liquid (IL) (2FF/Cu-TiO 2 /IL/CPE) was fabricated and employed to study the electrocatalytic oxidation of droxidopa, using cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV) as diagnostic techniques. It has been found that the oxidation of droxidopa at the surface of modified electrode occurs at a potential of about 295 mV less positive than that of an unmodified CPE. DPV exhibits a linear dynamic range from 5.0 × 10-8 to 4.0 × 10-4 M and a detection limit of 30.0 nM for droxidopa. Finally this modified electrode was used for simultaneous determination of droxidopa and tryptophan. Also the 2FF/Cu-TiO 2 /IL/CPE shows excellent ability to determination of droxidopa and tryptophan in real samples.

Carvacrol electrochemical reaction characteristics on screen printed electrode modified with La2O3/Co3O4 nanocomposite

“…Thirdly, nanomaterials can assist the electrode to preserve its characteristics for a long period of time [26]. So, a variety of nanomaterials have been synthesized and characterized for the electrochemical analysis [27][28][29][30][31][32].…”

Synthesis and characterization of LaMnO3 nanocrystals and graphene oxide: fabrication of graphene oxide–LaMnO3 sensor for simultaneous electrochemical determination of hydroquinone and catechol

“…However, a serious obstacle is that the oxidation peak potentials of the isomers are too close at a bare electrode which causes overlapping of voltammetric responses, making their discrimination very difficult [13][14][15][16][17]. A chemically modified electrode is a superior approach to solve the peak separation problem by applying a modifier [18][19][20][21][22][23][24]. Hence, a few modified electrodes have already been reported to determine HQ and CT such as GCE modified by carbon nanotubes (CNT), poly-amid sulfonic acid-CNTs, graphenechitosan composite, carbon nanotubes/poly (3-methylthiophene), penicillamine), Zn/Al layered double hydroxide film, or gold-graphene [25][26][27][28][29][30][31].…”

Synthesis of Magnetic Ordered Mesoporous Carbons (OMC) as an Electrochemical Platform for Ultrasensitive and Simultaneous Detection of Thebaine and Papaverine

“…However, electro-chemical methods are growingly used for detecting analytes due to the benefits such as rapid responses, lower limits of detection, affordability, easy operations, and lack of pre-treatment. [14][15][16][17][18][19] Nevertheless, oxidation peak potential of the analyte has serious overlap in several bare solid electrodes. If improvement of selectivity is the goal; thus, separation of the signals from each other would be necessary.…”