Using gold nanostars modified pencil graphite electrode as a novel substrate for design a sensitive and selective Dopamine aptasensor.
For the first time, gold nanostars (GNS) were applied for electrostatic and covalent immobilizing a thiol modified Dopamine aptamer on the pencil graphite electrode and signal amplification. Dopamine aptamer was immobilized on the gold nanostars through electrostatic interaction between negatively charged phosphate groups of aptamer and positively charged gold nanostars and AuS well known covalent interaction. In the presence of Dopamine in the test solution, the charge transfer resistance (RCT) on the electrode surface increased with the increase of the Dopamine concentration due to specific interaction between Dopamine aptamer and Dopamine molecules, which made a barrier for electrons and inhibited the electron-transfer. So, the proposed approach showed a high sensitivity and a wide linearity to Dopamine in the range from 1.0 (±0.1) to 100.0 (±0.3) ngL-1(ppt) with detection and quantification limits of 0.29 (±0.10) and 0.90 (±0.08) ngL-1(ppt), respectively. Finally, the sensor was successfully used for determination of Dopamine in biological (human blood plasma and urine) samples. The results open up the path for manufacturing cost effective aptasensors for other biomedical applications.
Faculty of Chemistry, Kharazmi University, Tehran, Iran. Electronic address: rasoulpourtaghavi@gmail.com.
Rasoul Pourtaghavi
RP
Talemi
Faculty of Chemistry, Kharazmi University, Tehran, Iran.
Seyed Mehdi
SM
Mousavi
Department of Chemistry, Faculty of Science, Lorestan University, Lorestan, Iran.
Hossein
H
Afruzi
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D058266:Dielectric Spectroscopy; D004298:Dopamine / Q000097:blood* / Q000652:urine*; D055664:Electrochemical Techniques; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012996:Solutions
D052157:Aptamers, Nucleotide; D004573:Electrolytes; D012996:Solutions; D006046:Gold; D006108:Graphite; D004298:Dopamine
Aptasensor; Biomedical application; Dopamine; Electrochemical impedance spectroscopy; Gold nanostars; Pencil graphite electrode