Fabrication of β‐Cyclodextrin/Glycine/Carbon Nanotubes Electrochemical Neurotransmitters Sensor – Application in Ultra‐sensitive Determination of DOPAC in Human Serum

Abstract

In this work, an electrochemical sensor was constructed by applying two successive thin layers of glycine‐carbon nanotubes mixture and β‐cyclodextrin (CNTs‐Gly)/CD over glassy carbon electrode surface for some neurotransmitters determination. A host‐guest interaction between CD and neurotransmitters molecules is expected and resulted in enhanced sensitivity, selectivity and stability of sensor response. Other components of the sensor are crucial for the unique electrochemical response. Carbon nanotubes allowed large surface area for glycine distribution that provided hydrogen bonding to CD moieties and contributed to facilitated charge transfer. It was possible to determine 3,4‐dihydroxy phenyl acetic acid (DOPAC) in the linear range of 0.1 μmol L−1 to 80 μmol L−1 with detection limit of 9.40 nmol L−1, quantification limit of 31.5 nmol L−1 and sensitivity of 4.16 μA/μmol L−1. The proposed sensor was applied in synthetic cerebrospinal fluids samples using random standard addition method. Also, the proposed sensor was used to determine DOPAC in presence of common interferences and acceptable recovery results were achieved for its analysis in real blood serum. Figures of merit for (CNTs‐Gly)/CD composite in terms of precision, robustness, repeatability and reproducibility were reported.

Carbon Nanotube‐phenolic Resin Composite Electrode Fabricated by Far Infrared‐assisted Crosslinking for Enhanced Amperometric Detection

“…CNTs in the composite electrode exhibit pronounced electrocatalytic activity toward the oxidation of synephrine and hesperidin. Their one‐dimensional structures allow them to be connected by PR to form electrical conduction pathways and electrocatalytic surface, which are crucially important for CE‐AD .…”

“…Because it owns unique nanostructures and promising properties of physics and chemistry, it has find a wide range of scientific and technological applications, such as sensors, electronics, energy storage and biomedicine . Because of its high electrical conductivity, high specific area and electrocatalytic activity, CNT has been employed to prepare a variety of electrochemical sensors and biosensors with improved performances .…”

“…CNT‐based electrochemical sensors and biosensors are mainly fabricated by surface modification . Drop coating was the most commonly used approach.…”

Electrochemical Sensing Platform Based on Nano‐Perovskite/Glycine/Carbon Composite for Amlodipine and Ascorbic Acid Drugs

“…has designed different electrochemical sensors based on CNTs confirming their performance . Decoration of CNTs surface with different nanomaterials as metals, metal oxides and polymers has improved the properties of CNTs and make them more advantageous for sensory applications . Mixed metal oxides particularly perovskites, ABO 3 , are considered one of the most important and frequently used catalysts in wide applications of fuel cells, catalysis, sensing, etc.…”

“…On the other hand, glycine (GL) as the simplest amino acid with one amino group and carboxyl group has attracted considerable interest as modifier for CNTs. Thus, modification of CNTs with glycine (physical suspension in dimethylformamide) can promote the charge transfer kinetics of DOPAC oxidation in terms of improved current response and reduced overvoltage . Furthermore, polymerization of glycine over CNTs paste electrode or immobilization of CNTs over poly (glycine) modified electrode can enhance the electroanalytical performance of CNTs.…”