A new immunosensing platform based on conjugated Poly(ThidEp-co-EDOT) copolymer for resistin detection, a new obesity biomarker

Aydın E. B., Aydın M., SEZGİNTÜRK M. K.

Microchimica Acta, vol.191, no.1, 2024 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 191 Issue: 1
  • Publication Date: 2024
  • Doi Number: 10.1007/s00604-023-06145-8
  • Journal Name: Microchimica Acta
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Analytical Abstracts, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Food Science & Technology Abstracts, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Keywords: Conjugated thiophene polymer, Electrochemical immunosensor, Electrochemical impedance spectroscopy, Modified electrode, Obesity, Resistin, Single-frequency impedance
  • Çanakkale Onsekiz Mart University Affiliated: Yes


The design of a novel electrochemical impedimetric biosensor for label-free analysis of resistin, a biomarker for obesity, is reported. For the fabrication of the immunosensor, a novel approach composed of electrochemical copolymerization of double epoxy groups-substituted thiophene (ThidEp) and 3,4-Ethylenedioxythiophene (EDOT) monomers was utilized. Anti-resistin antibodies were covalently attached to the copolymer-coated electrode. The capture of resistin antigens by anti-resistin antibodies caused significant variations in charge transfer resistance (R ct) because of the immunoreactions between these proteins. Under optimum experimental variables, the changes in impedance signals were employed for the determination of resistin antigen concentration, and the prepared immunosensor based on conjugated copolymer illustrated a wide linear range between 0.0125 and 22.5 pg/mL, a low detection limit (LOD) of 3.71 fg/mL, and a good sensitivity of 1.22 kΩ pg−1mL cm2. The excellent analytical performance of the resistin immunosensor in terms of selectivity, sensitivity, repeatability, reproducibility, storage stability, and low detection limit might be attributed to the conductive copolymer film layer generation on the disposable indium tin oxide (ITO) platform. The capability of this system for the determination of resistin in human serum and saliva samples was also tested. The immunosensor results were in accordance with the enzyme-linked immunosorbent assay (ELISA) results. The matrix effects of human serum and saliva were also investigated, and the proposed immunosensor displayed good recovery ranging from 95.91 to 106.25%. The engineered immunosensor could open new avenues for obesity monitoring. Graphical Abstract: [Figure not available: see fulltext.]