Fabrication of an ultrasensitive and selective electrochemical aptasensor to detect carcinoembryonic antigen by using a new nanocomposite

• Published in: Biosensors & bioelectronics Vol. 129; pp. 1 - 6
• Main Authors: Mazloum- Ardakani, Mohammad, Tavakolian- Ardakani, Zahra, Sahraei, Nafiseh, Moshtaghioun, Seyed Mohammad
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.03.2019
• Subjects: Aptamer; Carcinoembryonic antigen (CEA); Electrochemical aptasensor; Graphene; Hemin; Multi-walled carbon nanotube; Aptamer; Hemin; Electrochemical aptasensor; Carcinoembryonic antigen (CEA); Graphene; Multi-walled carbon nanotube
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2018.12.047

A lable-free electrochemical aptasensor was successfully developed for the sensitive detection of carcinoembryonic antigen as a tumor biomarker. To do this, a ternary nanocomposite of hemin, graphene oxide and multi-walled carbon nanotubes was used. The aptamer can be attached to the surface of a hemin, graphene oxide and multi-walled carbon nanotubes glassy carbon electrode through –NHCO- covalent bonds to form a sensing surface. Through fourier transform infrared spectroscopy and scanning electron microscopy, it was indicated that hemin can be successfully incorporated into hemin, graphene oxide and multi-walled carbon nanotubes. Hemin, which protects graphene nanosheets, also serves as an in-situ probe owing to its well-defined redox properties. Multi-walled carbon nanotubes in the modifier enhance conductivity and facilitate the electron transfer between hemin and the glassy carbon electrode. In this study, carcinoembryonic antigen got specifically bound to the aptamer, and the current changes were used for selective and specific detection of that antigen. The devised aptasensor proved to have excellent performance with a wide linear range of 1.0 × 10–15 – 1.0 × 10−8 gmL−1 and a detection limit of 0.82 fg mL−1. The inter-day and intra-day values of RSD% were obtained in the range of 0.10–2.91 and 2.21–4.56 respectively. According to the experiments conducted on real samples, it may be claimed that the proposed label-free electrochemical aptasensor is capable enough of determining carcinoembryonic antigen in clinical diagnostics. •The electrochemical properties of an aptasensor for CEA detection were improved using the HGNs-MWCNTs nanocomposite.•Hemin was attached to the surface of the modified electrode, which provided a good interface for connection of the aptamer to the surface electrode.•The proposed biosensor has a low limit of detection (0.82 fgm L−1) and a wide linear range (1 × 10–15 to 1 × 10−8 gmL−1).