Voltammetric carbon nanotubes based sensor for determination of tryptophan in the milk sample

Abstract

In this research, functionalized carbon nanotubes were employed to modify a glassy carbon electrode (F-MWCNT/GCE). Several techniques including Fourier Transform Infrared Spectroscopy, scanning electron microscopy, and transmission electron microscopy were utilized for characterization of F-MWCNT. The electrochemical activity of the developed electrode was assessed by differential pulse voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy. The electrochemical results demonstrated that oxidation of tryptophan (TRP) caused a higher anodic peak current than unmodified GCE. The F-MWCNT/GCE offered a detection limit of 3.63 nM and dynamic ranges of 0.01-0.7 µM for analysis of TRP by the differential pulse voltammetry method. Moreover, tryptophan detection was achieved successfully using F-MWCNT/ GCE in milk samples. It can be stated that this method paves the way for a selective, sensitive and straightforward method to determine tryptophan in the real food sample.

A sensitive voltammetric sensor for specific recognition of vitamin C in human plasma based on MAPbI3 perovskite nanorods

“…The charge transfer resistance magnitude at the respective electrodes was ascribed to the diameters of the depressed semicircles. As shown, the charge transfer resistance at L-cys@MAPbI3/GCE surface is decreased about 1.7-fold compared to the bare electrode (23.57 kΩ), indicating fast electron transfer on the electrode surface [27]. Results confirmed that the presence of L-cys and MAPbI3 increases the electrode surface's conductivity [28].…”

The Determination of Timolol Maleate Using Silver/Tannic Acid/Titanium Oxide Nanocomposite as an Electrochemical Sensor in Real Samples

“…The electrochemical active surface area (EASA) was calculated using the Randles-Sevcik equation (Eq. 3) [39,40]. The EASAs value were observed to be 0.062, 0.075, 0.069 and 0.14 cm 2 for GCE, TiO 2 , Ag@TiO 2 /GCE and Ag/TA@TiO 2 /GCE, respectively.…”

Monitoring of Butylated Hydroxyanisole in Food and Wastewater Samples Using Electroanalytical Two-Fold Amplified Sensor

“…Accordingly, measurement methods have been used for many years as a suitable strategy to evaluate the quality of food products [8]. Various measurement methods such as chromatography, spectroscopy, and electrochemical sensors have been proposed to monitor food composition [9][10][11][12][13]. Electrochemical methods have received greater attention than the other techniques [14,15].…”