title: Electrochemical bioassay development for ultrasensitive aptasensing of prostate specific antigen.
abstract: A densely packed gold nanoparticles on the rGO-MWCNT platform was used as the basis for an ultrasensitive label-free electrochemical aptasensor to detect the biomarker prostate specific antigen (PSA) in serum. The detection was based on that the variation of electron transfer resistance (Rct) and differential pulse voltammetry (DPV) current were relevant to the formation of PSA-aptamer complex at the modified electrode surface. Compared with pure AuNPs, rGO-MWCNT and MWCNT/AuNPs, the rGO-MWCNT/AuNPs nanocomposite modified electrode was the most sensitive aptasensing platform for the determination of PSA. Two calibration curves were prepared from the data obtained from the DPV and electrochemical impedance spectroscopy (EIS) by plotting the peak current and Rctagainst PSA concentration, respectively. The proposed aptasensor had an extremely low LOD of 1.0pgmL-1PSA within the detection range of 0.005-20ngmL-1and 0.005-100ngmL-1for DPV and EIS calibration curves, respectively. This sensor exhibited outstanding anti-interference ability towards co-existing molecules with good stability, sensitivity, and reproducibility. Clinical application was performed with analysis of the PSA levels in serum samples obtained from patients with prostate cancer using both the aptasensor and Immunoradiometric assay. The results revealed the proposed system to be a promising candidate for clinical analysis of PSA.
authors.affiliation: Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, 77188-97111, Iran; High Temperature Fuel Cell Research Group, Vali-e-Asr University of Rafsanjan, 77188-97111, Iran. Electronic address: heydari1983@gmail.com.
authors.forename: Esmaeil
authors.initials: E
authors.lastname: Heydari-Bafrooei
authors.affiliation: Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, 77188-97111, Iran.
authors.forename: Nazgol Sadat
authors.initials: NS
authors.lastname: Shamszadeh
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D058266:Dielectric Spectroscopy / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000648:ultrastructure; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis; D015203:Reproducibility of Results
chemical_list: D052157:Aptamers, Nucleotide; D037742:Nanotubes, Carbon; D006046:Gold; D006108:Graphite; D017430:Prostate-Specific Antigen
keywords: Aptamer; Electrochemical impedance spectroscopy; Label free detection; Multiwalled carbon nanotubes; Prostate specific antigen