title: Design and characterization of electrochemical dopamine-aptamer as convenient and integrated sensing platform.
abstract: Here, an ultrasensitive label-free electrochemical aptasensor was developed for dopamine (DA) detection. Construction of the aptasensor was carried out by electrodeposition of gold-platinum nanoparticles (Au-PtNPs) on glassy carbon (GC) electrode modified with acid-oxidized carbon nanotubes (CNTs-COOH). A designed complementary amine-capped capture probe (ssDNA1) was immobilized at the surface of PtNPs/CNTs-COOH/GC electrode through the covalent amide bonds formed by the carboxyl groups on the nanotubes and the amino groups on the oligonucleotides. DA-specific aptamer was attached onto the electrode surface through hybridization with the ssDNA1. Methylene blue (MB) was used as an electrochemical indicator that was intercalated into the aptamer through the specific interaction with its guanine bases. In the presence of DA, the interaction between aptamer and DA displaced the MB from the electrode surface, rendering a lowered electrochemical signal attributed to a decreased amount of adsorbed MB. This phenomenon can be applied for DA detection. The peak current of probe (MB) linearly decreased over a DA concentration range of 1-30 nM with a detection limit of 0.22 nM.
authors.affiliation: Department of Chemistry, Islamic Azad University, Khorramabad Branch, Khorramabad, Iran. Electronic address: azadbakht.a@gmail.com.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Azadbakht
authors.affiliation: Department of Chemistry, Ilam University, Ilam, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Roushani
authors.affiliation: Department of Chemistry, Islamic Azad University, Khorramabad Branch, Khorramabad, Iran.
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Abbasi
authors.affiliation: Department of Chemistry, Islamic Azad University, Khorramabad Branch, Khorramabad, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Derikvand
mesh_terms: D052157:Aptamers, Nucleotide / Q000138:chemical synthesis / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D004298:Dopamine / Q000032:analysis*; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D013499:Surface Properties
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D010984:Platinum; D002244:Carbon; D006046:Gold; D008751:Methylene Blue; D004298:Dopamine
keywords: Aptasensor; Dopamine; Gold–platinum nanoparticles; Methylene blue