Reduced graphene oxide-chitosan-aptamer interface as new platform for ultrasensitive detection of human epidermal growth factor receptor 2

• Published in: Biosensors & bioelectronics 2017-09, Vol.95, p.117-123
• Main Authors: Tabasi, Arezoo, Noorbakhsh, Abdollah, Sharifi, Ensiyeh
• Format: Article
• Language: English
• Subjects: Aptamer; Aptamers, Nucleotide - chemistry; Biosensing Techniques; Biosensor; Chitosan - chemistry; Electrochemical Techniques; Graphite - chemistry; Human epidermal growth factor receptor 2; Humans; Limit of Detection; Modified electrode; Receptor, ErbB-2 - chemistry; Receptor, ErbB-2 - isolation & purification; Reduced graphene oxide-chitosan; Tumor marker
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2017.04.020

The present work describes an ultrasensitive electrochemical aptamer-based assay for detection of human epidermal growth factor receptor 2 protein (HER2) cancer biomarker as a model analyte. Results show that the reduced graphene oxide-chitosan (rGO-Chit) film as a suitable electrode material possesses great favorable properties including high homogeneity, good stability, large surface area and high fraction of amine groups as aptamer binding sites. Various steps of aptasensor fabrication were characterized using microscopic, energy-dispersive X-ray spectroscopy (EDAX), Fourier transform infrared (FTIR) spectroscopy and electrochemical techniques. Using methylene blue (MB) as an electrochemical probe and differential pulse voltammetry (DPV) technique, two linear concentration ranges of 0.5–2ngml−1 and 2–75ngml−1 were obtained with a high sensitivity of 0.14μAng−1ml and a very low detection limit of 0.21ngml−1 (very lower than the clinical cut-off). The fabricated aptasensor showed excellent selectivity for detection of HER2 in complex matrix of human serum samples. The sensitive detection of HER2 can be attributed to the multiple signal amplification of MB during its accumulation to the modified electrode surface via both affinity interaction to aptamer molecules and electrostatic adsorption to the HER2 analyte as well as high charge transfer kinetic properties of the applied rGO-Chit film. The rapid and simple preparation of the proposed aptasensor as well as its high selectivity, stability and reproducibility provided a promising protocol for non-invasive diagnosis for various points of care application. The proposed aptasensor showed excellent analytical performance in comparison with current HER2 biosensors. •A novel and highly sensitive electrochemical aptasensor for detection of HER2 cancer marker was fabricated.•The rGO-Chit film provided a very favorable environment with high homogeneity and stability for the immobilization of aptamer molecules.•Multiple signal amplification and high selectivity of the HER2 aptamer resulted in very good analytical performances.•The proposed HER2 aptasensor can be used for determination of HER2 in human serum samples