Analytical Chemistry
Author:
Keywords:
self-assembled monolayers, glassy-carbon electrode, low-dose dopamine, early renal dysfunction, rat prefrontal cortex, ascorbic-acid, pharmaceutical-preparations, uric-acid, macrocyclic polyamines, amperometric detection, Science & Technology, Physical Sciences, Chemistry, Analytical, Chemistry, SELF-ASSEMBLED MONOLAYERS, GLASSY-CARBON ELECTRODE, LOW-DOSE DOPAMINE, EARLY RENAL DYSFUNCTION, RAT PREFRONTAL CORTEX, ASCORBIC-ACID, PHARMACEUTICAL-PREPARATIONS, URIC-ACID, MACROCYCLIC POLYAMINES, AMPEROMETRIC DETECTION, Biosensing Techniques, Dopamine, Dopamine Agents, Electrochemistry, Electrodes, Gold, Humans, Porphyrins, Sensitivity and Specificity, 0301 Analytical Chemistry, 0399 Other Chemical Sciences, Analytical Chemistry, 3205 Medical biochemistry and metabolomics, 3401 Analytical chemistry, 4004 Chemical engineering
Abstract:
Here, we report on an ion-channel mimetic sensor using self-assembly monolayers deposited onto gold electrodes for electrochemical determination of dopamine. The different compositions of the modification solution consist of corrole-SH and other thiol derivatives used as the "background compounds" such as 1-dodecanethiol (DDT), 6-mereapto-1-hexanol (HS(CH2)(6)OH), or 11 -mercapto-1-undecanol (HS(CH2)(11)OH) were explored to find the best self-assembled monolayer (SAM) suitable for dopamine determination. Among them, the mixed SAM consisting of corroles with the -SH group and 6-mercapto-1-hexanol (HS(CH2)(6)OH) in the molar ratio 1:10 was the most sensitive. The signals generated by the formation of a complex between the corrole host and the dopamine guest were measured by Osteryoung square-wave voltammetry (OWN) and electrochemical impedance spectroscopy (EIS) with [Ru(NH3)(6)](3+) as an electroactive marker. The developed sensor was free of interferences of components, of human plasma such as ascorbic acid, creatinine, creatine, and uric acid. The detection limits observed by EIS in buffer solution and in the presence of centrifuged human plasma 80 times diluted with a 0.9% NaCl containing 0.01 M borate buffer solution of pH 7.0 were 3.3 x 10(-12) and 5.3 x 10(-12) M, respectively.