A High Sensitive Electrochemical Nanoimmunosensor Based on Fe3o4/Tmc/Au Nanocomposite and Pt-Modified Electrode for the Detection of Cancer Biomarker Epidermal Growth Factor Receptor Publisher



Omidfar K^{1, 2} ; Darzianiazizi M² ; Ahmadi A¹ ; Daneshpour M¹ ; Shirazi H¹ Show Affiliations
Source: Sensors and Actuators# B: Chemical Published:2015

Abstract

A novel chip format sandwich electrochemical immunoassay was developed for ultrasensitive detection of epidermal growth factor receptor (EGFR) using Fe3O4/N-trimethyl chitosan/gold (Fe3O4/TMC/Au) nanocomposite as a tracing tag to label anti-EGFR VHH antibody (or nanobody) and polythiophene (PT) as immobilization platform. The EGFR is considered as an important biomarker because its overexpression is commonly observed in many aggressive cancer types. The nano-immunoassay (combination of nanocomposite and nanobody) was performed on a commercial screen-printed platinum electrode and provided sensitivity within femtogram/milliliter levels of soluble EGFR in 25 μL samples. Furthermore, the study of long-term stability demonstrated the acceptable efficiency of this nanoimmunosensor for more than eight weeks. Apart from demonstration of using nanobodies for nano-electrochemical based immunoassays, the extremely low and clinically relevant detection limits of EGFR demonstrate the direct applicability of this nanoimmunosensor to fast and sensitive biomarker detection in clinical diagnostics. © 2015 Elsevier B.V. All rights reserved © 2015 Elsevier B.V. All rights reserved.