Label-free and ultrasensitive electrochemical cotinine sensing based on bio-modified magnetic nanoparticles


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

Sensors and Actuators B: Chemical, vol.408, 2024 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 408
  • Publication Date: 2024
  • Doi Number: 10.1016/j.snb.2024.135476
  • Journal Name: Sensors and Actuators B: Chemical
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Analytical Abstracts, Biotechnology Research Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Keywords: Cotinine, Label-free analysis, Magnetic iron oxide nanoparticles, Magneto-biosensor
  • Çanakkale Onsekiz Mart University Affiliated: Yes

Abstract

Herein, a label-free impedimetric magneto-biosensor was constructed for detection of cotinine, a promising marker of active and passive smoking. Indium tin oxide sheet (ITO) was utilized as a working electrode and modified magnetic iron oxide (Fe3O4) nanoparticles were attached to the electrode with a neodium magnet. Magnetic iron oxide nanoparticles were modified with a conjugated carboxyl-functionalized poly(pyrrolepropionic acid) (PPPAc) polymer to increase the area and improve the conductivity, which were utilized to immobilize anti-cotinine antibodies. Anti-cotinine antibodies were specific recognition elements, and a selective sensing platform was constructed by covalent binding of anti-cotinine antibodies. The impedimetric signal was changed with a reaction between cotinine analytes and anti-cotinine antibodies, and the proposed biosensor demonstrated excellent sensitivity, with a wide linear range from 2 to 500 pg/mL and a low detection limit of 0.579 pg/mL. Additionally, this newly constructed magneto-biosensor demonstrated high sensitivity, good reproducibility, and superior specificity. In order to test clinical applicability, serum and saliva samples were analysed with the suggested biosensor, and it indicated excellent performance in comparison with the gold standard methods of enzyme-linked immunoassay (ELISA) and high-performance liquid chromatography (HPLC) systems for the analysis of cotinine. These results displayed that the immunosensor could be potentially useful for clinical diagnostics.