Electrochemical Characterization of Gold 6‐Amino‐2‐mercaptobenzothiazole Self‐Assembled Monolayer for Dopamine Detection in Pharmaceutical Samples

Abstract

A new sensor, gold-6-amino-2-mercaptobenzothiazole (6A2MBT), was fabricated via a self-assembly procedure. Electrochemical properties of the monolayer were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The modified electrode showed excellent antifouling property against the oxidation products of DA, allowed us to construct a dynamic calibration curve with two linear parts, 1.00 Â 10 À6 to 3.72 Â 10 À4 and 3.72 Â 10 À4 to 6.42 Â 10 À4 M DA, with correlation coefficients of 0.997 and 0.992 and a detection limit of 1.57 Â 10 À7 M DA by using differential pulse voltammetry (DPV), respectively. Finally, the performance of the Au-6A2MBT modified electrode was successfully tested for electrochemical detection of DA in a pharmaceutical sample.

Oxinate-Aluminum(III) Nanostructure Assemblies Formed via In-situ and Ex-situ Oxination of Gold-Self-Assembled Monolayers Characterized by Electrochemical, Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy, and X-ray Photoelectron Spectroscopy Methods

“…Among several neutral redox probes, like FcMeOH [34,56], ascorbic acid, dopamine [52,57] and PBQ [58] used to trace modification of the electrode surface, the FcMeOH probe was found to be the most appropriate, because it neither modifies the background current Table 2.…”

“…However, assumption (2) is in good agreement with the conclusion drown in Section 3.3.5, that is "adsorption of 8HQ on in-situ prepared Au-MPA-5A8HQ-Al(III) electrode, which suggests presence of some uncoordinated sites on the Au-MPA-5A8HQ-Al(III) electrode surface having coordination capacity towards the incoming 8HQ". Furthermore, from the voltammetry desorption experiments[52] carried out on the Au-MPA surface, a value of  MPA = 7.5410 10 mole cm 2 is obtained for the surface coverage of MPA.Combining this voltammetry data with atomic ratios obtained from XPS experiment, resultsin the values of  MPA = 7.5410 10 ,  5A8HQ = 2.6510 10 and  Al(III) = 1.3210 10 for the surface concentrations of MPA, 5A8HQ and Al(III).3.5. Reproducibility, stability against electrolyte solutions and durability (stability) against time (i) Reproducibility: Reproducibility shows the degree of agreement of measurements on the replicate devices, so it is assessed by means of precisions.…”

Simultaneous electrochemical detection of the catecholamines and ascorbic acid at PEDOT/S-β-CD modified gold electrodes

“…In a polymer matrix, however, access to the S-b-CD cavity is likely to be hindered or blocked due to the random formation of the polymer strands network. SAM of thiolated-CD's have been used to detect DA, with between 53.5% and 70% CD coverage on the surface [58,59], yielding sensors with a high degree of accessible CD sites. The number of CD active sites accessible to DA in the PEDOT/S-b-CD used here is difficult to determine for two main reasons; (i) the MW of S-b-CD is not accurately known and, (ii) adsorption of analyte at the modified surface is not solely promoted by the S-b-CD.…”

A Dopamine Sensor Based on Pre-Concentration by Magnetic Nanoparticles

“…Therefore, understanding its electrochemical properties and quantifying its presence in human body fluids are the most important. Dopamine can be easily oxidized electrochemically at conventional electrodes, which have been used to detect the neurotransmitter [3][4][5][6][7]. Apart from the need to reach low detection limits, determination of the DA is complicated by the coexistence of many interfering compounds.…”

“…To meet this challenge, a variety of modified electrodes have been proposed. These include self-assembled monolayer electrodes [5][6][7], polymer electrodes [11,12], and nanomaterial film electrodes [13][14][15]. However, in all cases two general strategies were employed for detection of DA; (i) separation of DA and AA oxidation potentials, or (ii) selective preconcentration of DA and following its determination [16].…”