Label-Free Electrochemical
Immunosensor Based on Conjugated
Polymer Film Coated Disposable Electrode for Ultrasensitive Determination
of Resistin Potential Obesity Biomarker
posted on 2024-02-24, 02:29authored byElif Burcu Aydın, Muhammet Aydın, Mustafa Kemal Sezgintürk
A new label-free immunosensor was
designed for sensitive
detection
of resistin obesity biomarker in human biological fluids. To construct
a sensing interface, the monomer of double epoxy groups-substituted
thiophene (TdiEpx) was synthesized for the fabrication
of the biosensing system. A disposable indium tin oxide sheet was
first modified by electrochemical polymerization of the TdiEpx monomer, and this robust and novel surface was characterized using
different spectroscopic and electrochemical analyses. The double epoxy
ends were linked to the amino ends of anti-resistin, and they served
as binding points for the covalent binding of biomolecules. The double
epoxy ends present in each TdiEpx monomer ensured
an extensive surface area, which improved the quantity of attached
anti-resistin. The determination of resistin antigen was based on
the specific coupling of resistin with anti-resistin, and this interaction
hindered the electron transfer reaction. The immunosensor introduced
a wide linear range of 0.0125–15 pg/mL, a low detection limit
of 4.17 fg/mL, and an excellent sensitivity of 1.38 kohm pg mL–1 cm2. In this study, a sandwich enzyme-linked
immunosorbent assay spectrophotometric method was utilized as a reference
technique for the quantitative analysis of resistin in human serum
and saliva samples. Both measurements in clinical samples displayed
correlations and high-correlation coefficients. In addition, this
immunosensor had good storage stability, acceptable repeatability
and reproducibility, high specificity, and good accuracy. The proposed
immunosensor provided a simple and versatile impedimetric immunosensing
platform and a promisingly sensitive way for clinical applications.