Ultrasensitive Determination of Glial-Fibrillary-Acidic-Protein (GFAP) in Human Serum-Matrix with a Label-Free Impedimetric Immunosensor.
Goksu OzcelikayFariba MollarasouliMehmet Altay ÜnalKıvılcım GucuyenerSibel Ayşıl ÖzkanPublished in: Biosensors (2022)
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.
Keyphrases
- label free
- gold nanoparticles
- ionic liquid
- endothelial cells
- high throughput
- living cells
- sensitive detection
- binding protein
- computed tomography
- squamous cell carcinoma
- high resolution
- small molecule
- solid phase extraction
- protein protein
- solid state
- magnetic nanoparticles
- cerebrospinal fluid
- spinal cord
- liquid chromatography
- induced pluripotent stem cells