Dopamine Sensor Based on a Composite of Silver Nanoparticles Implemented in the Electroactive Matrix of Calixarenes

Abstract

A sensitive electrochemical sensor based on a composite containing silver nanoparticles and a redox active thiacalixarene with catechol fragments in the substituents at the lower rim has been developed and used for dopamine detection. The electrochemical investigation of thiacalixarene in homogeneous solution and on the electrode interface showed the reversible character of the redox conversion of catechol fragments and its involvement in the chemical reduction of silver which resulted in formation of uniform nanoparticles of 4-6 nm in diameter. The use of such a material for electrode modification made it possible to record a high amplitude cathodic signal at À700 mV that was proportional to the dopamine concentration within 1 nM-1 mM. (limit of detection 0.5 nM).

Fabrication of Silver Nanoparticles Decorated on Activated Screen Printed Carbon Electrode and Its Application for Ultrasensitive Detection of Dopamine

“…The anodic peak at 0.232 V is due to the two‐electron oxidation of DA to dopaminoquinone and the cathodic peak at 0.115 V is due to the subsequent reduction of dopaminoquinone to DA in a reversible two electron process (step 1). As reported earlier that DA exists mainly in protonated form blow pH 7 and the intramolecular 1, 4‐Michael addition for DA is weak 36,37. Moreover, when the pH of solution is equal or more than 7 the amount of unprotonated dopaminoquinone is sufficient for the cyclization reaction to form leuco‐dopaminoquinone (step 2).…”

Electrochemical Aptasensor for the Determination of Ochratoxin A at the Au Electrode Modified with Ag Nanoparticles Decorated with Macrocyclic Ligand

“…The silver nanoparticles were obtained by the method adapted from 36. To accelerate the formation of Ag nanoparticles, triethylamine was added to the reaction mixture.…”

“…The sediment was neutralized with solid NaHCO 3 , resuspended from THF by water and recrystallized from acetone. The structure of the product was confirmed by physical methods and elemental analysis 36. For the synthesis of Ag nanoparticles, 250 µL of thiacalix[4]arene solution in acetone were mixed with 20 µL of 0.01 M aqueous AgNO 3 solution and 2.5 µL of 0.01 M triethylamine in acetone.…”

“…5,11,17,23‐Tetra‐ tert ‐butyl‐25,26,27,28‐tetrakis‐[1‐(2′‐hydroxyethyl)‐ N ‐(3′′,4′′‐dihydroxy‐phenyl)‐amidocarbonyl)‐methoxy)‐2,8,14,20‐tetrathiacalix[4]arene in 1,3‐alternate conformation was synthesized at the Organic Chemistry Department of Kazan Federal University as described elsewhere 36. Briefly, tetraacid derivative of thiacalix[4]arene was consecutively treated with SOCl 2 and dopamine hydrochloride in THF followed by the addition of triethylamine.…”

The Role of Calix[n]arenes and Pillar[n]arenes in the Design of Silver Nanoparticles: Self-Assembly and Application

“…Chemical reduction takes several hours, and the obtained coating is more uniform and acts as more effective electrochemical sensing nanomaterial when compared to electrochemically reduced silver salt on the TCA-27-coated electrode. With variations in other components of electrochemical sensors, these nanoparticles were successfully used for dopamine [95] and ochratoxin determination [96]. This approach has allowed to obtain electrochemical sensors for cholinesterase, where quaternary ammonium derivatives of thiacalixarene TCA-22-TCA-24 act as cholinesterase inhibitors [97].…”