Fullerene-PAMAM(G5) composite modified impedimetric biosensor to detect Fetuin-A in real blood samples.

The aim of this study is to develop a nanomaterial-dendrimer composite modified biosensor to detect Fetuin-A (HFA) in real blood samples. For this purpose, we designed an Electrochemical Impedance Spectroscopy (EIS) based anti-Fetuin-A (Anti-HFA) modified biosensor system and tested in real blood samples. Chronoimpedance was also employed. The same samples were analyzed with ELISA and the results were compared for validation of the new system. Gold screen printed electrodes (AuSPE) were used as transducer. Firstly, a self-assembly monolayer (SAM) was formed on gold surface by 4-aminothiophenol (4-ATP), Fullerene and PAMAM-NH2 (G5), layers were formed, consecutively. Then Anti-HFA was immobilized on Au/4-ATP/Fullerene/PAMAM electrode via glutaraldehyde. The chronoimpedance test was employed to investigate the optimum analysis duration. According to the data of chronoimpedance, the total analysis time for EIS was chosen as 3 min. The new biosensor was compared with the ELISA method which required 150 min. The calibration curve was prepared electron transfer resistance of the electrode (ΔRet) per minute as ohm and 1.66-134 ng/mL.min with a R2  = 0.9912. The LOD and LOQ of the biosensor was calculated as 0.48 ng/mL.min, 1.46 ng/mL.min, respectively. Linear regression analysis indicated that the novel developed biosensor results agreed well with that of the conventional ELISA assay.