An electrochemical dopamine aptasensor using the modified Au electrode with spindle-shaped gold nanostructure

Formation and Electrochemical Evaluation of Polyaniline and Polypyrrole Nanocomposites Based on Glucose Oxidase and Gold Nanostructures

“…Metal nanoparticles and nanostructures of gold, silver and cooper are used in recent modifications of glucose biosensors due to their unique catalytic and/or charge transfer properties [ 21 , 22 , 23 , 25 ]. The electrochemical performance of graphite-based sensors can be improved by the modification with nanoparticles [ 3 , 25 , 26 , 27 , 28 ] and/or other nanostructures [ 17 , 19 , 20 , 23 , 29 , 30 , 31 ]. Among many metal-based nanoparticles, gold nanoparticles (AuNPs) are the most promising nanomaterials due to their large surface area, high loading efficiency, possible involvement in direct and indirect charge transfer and stabilization of the enzyme through electrostatic interactions and/or strong binding with sulfur-containing groups [ 2 , 4 , 18 , 32 ].…”

“…Dendritic gold nanostructures of 10–200 nm are characterized by three-order hierarchy-based fractals [ 22 , 23 , 33 ]. Positively electrically charged gold nanostructures can establish stabile interaction with negatively electrically charged aptamers [ 31 ]. Gold compounds are used as connectors between the surface of an electrode and the red-ox center of GOx [ 20 ].…”

A Comprehensive Review on Developed Pharmaceutical Analysis Methods by Iranian Analysts in 2018

“…Shahbakhsh et al 74 also measured dopamine in the spiked serum and urine samples with LOQ and LOD of 0.6 µmol L -1 and 20 nmol L -1 , respectively. While Taheri et al 77 used a DPV method for dopamine determination by using the modified Au electrode with spindle-shaped gold nanostructure in serum sample with LOQ and LOD of 0.16 nmol L -1 and 13 pmol L -1 , respectively. They reported a dopamine serum level of 0.16 nmol L -1 for healthy subjects and 0.35 -1.23 nmol L -1 for patient subjects.…”

From Small Molecules toward Whole Cells Detection: Application of Electrochemical Aptasensors in Modern Medical Diagnostics

“…The analysis was conducted in flow injection mode, where the aptasensor response to dopamine was within ≈1 s (almost instantly after the dopamine injection), the sensitivity 67 ± 1 nA μM−1 cm −2 , and the dopamine lower limit of detection (LOD) was 62 nM ( Figure 7 ). Nonetheless, despite numerous electrochemical dopamine aptasensors mentioned in the literature [ 92 , 93 , 94 , 95 , 96 ], still, the greatest challenge is its accurate measurement in body fluids. This is related to numerous neurochemical events after the dopamine (or other neurotransmitters) release, which lead to its transformation at the time-scale of a few seconds or less (the dopamine lifetime ranges from 100 to 0.05 s and depends on the current state of the organism).…”

“…The best example of such are gold nanoparticles (AuNPs) and their composites. They are still very popular in the electrochemical aptasensors development because of their unique physical and chemical properties, such as a large surface area, a strong plasmonic characteristic, and easy functionalization with the use of self-organized monolayers [ 13 , 49 , 62 , 73 , 95 , 148 , 158 , 184 , 185 , 186 ]. This allowed for aptasensors development with excellent analytical performances and the cost-effective detection of various types of analytes in different types of matrixes with the use of conventional electrochemical measurement techniques such as cyclic voltammetry (CV), DPV, square wave voltammetry (SWV).…”