Ultrasensitive Determination of Glial-Fibrillary-Acidic-Protein (GFAP) in Human Serum-Matrix with a Label-Free Impedimetric Immunosensor

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Ozcelikay G., Mollarasouli F., ÜNAL M. A., Gucuyener K., ÖZKAN S. A.

BIOSENSORS-BASEL, cilt.12, sa.12, 2022 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 12 Sayı: 12
  • Basım Tarihi: 2022
  • Doi Numarası: 10.3390/bios12121165
  • Dergi Adı: BIOSENSORS-BASEL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, EMBASE, INSPEC, MEDLINE, Directory of Open Access Journals
  • Anahtar Kelimeler: label-free impedance immunosensor, screen printed carbon electrode (SPCE), Au nanoparticles (Au NPs), glial fibrillary acidic protein (GFAP), SELF-ASSEMBLED MONOLAYERS, TRAUMATIC BRAIN-INJURY, BIOSENSOR
  • Ankara Üniversitesi Adresli: Evet

Özet

In this work, immobilizing anti-GFAP antibodies via covalent attachment onto L-cysteine/gold nanoparticles that were modified with screen-printed carbon electrodes (Anti-GFAP/L-cys/AuNps/SPCE) resulted in the development of a sensitive label-free impedance immunosensor for the detection of Glial Fibrillary Acidic Protein (GFAP). The immunosensor's stepwise construction was studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). L-cysteine was chosen as the linker between GFAP antibodies and Au NPs/SPCE because it enables the guided and stable immobilization of GFAP antibodies, thus resulting in increased immunosensor sensitivity. As a redox probe, 5 mM of [Fe(CN)6]3-/4- was used to measure the electron-transfer resistance (Ret), which was raised by the binding of antigens to the immobilized anti-GFAP on the surface of the modified electrode. A linear correlation between Rct and GFAP concentration was achieved under optimum conditions in the range of 1.0-1000.0 pg/mL, with an extraordinarily low detection limit of 51.0 fg/mL. The suggested immunosensor was successfully used to detect the presence of GFAP in human blood serum samples, yielding good findings. As a result, the proposed platform may be utilized to monitor central nervous system injuries.