title: Electrochemical aptamer/antibody based sandwich immunosensor for the detection of EGFR, a cancer biomarker, using gold nanoparticles as a signaling probe.
abstract: Detection of epidermal growth factor receptor (EGFR) in biological fluids is of paramount importance, since it has significant application in cancer diagnosis, drug development, and therapy monitoring. EGFR is a cancer biomarker, and its overexpression is associated with the development of some types of cancer. Herein, we report on the development of a sensitive and selective electrochemical aptamer/antibody (Apt/Ab) sandwich immunosensor for detection of EGFR. In this study, a biotinylated anti-human EGFR Apt was immobilized on streptavidin-coated magnetic beads (MB) and served as a capture probe. A polyclonal anti-human EGFR Ab was conjugated to citrate-coated gold nanoparticles (AuNPs) and used as a signaling probe. In the presence of EGFR, an Apt-EGFR-Ab sandwich was formed on the MB surface. The extent of the complexation was evaluated by differential pulse voltammetry of AuNPs after their dissolution in HCl. Under optimal conditions, the dynamic concentration range of the immunosensor for EGFR spanned from 1 to 40 ng/mL, with a low detection limit of 50 pg/mL, and RSD percent of less than 4.2%. The proposed approach takes advantage of sandwich assay for high specificity, MBs for fast separation, and electrochemical method for cost-effective and sensitive detection. In this proof-of-principle study, we demonstrate the potential clinical efficacy of the immunosensor for monitoring of chemotherapy effectiveness in breast cancer samples.
authors.affiliation: Department of Chemistry, Tarbiat Modares University, Tehran 14115-175, Iran.
authors.forename: Hoda
authors.initials: H
authors.lastname: Ilkhani
authors.affiliation: Department of Chemistry, Tarbiat Modares University, Tehran 14115-175, Iran.
authors.forename: Morteza
authors.initials: M
authors.lastname: Sarparast
authors.affiliation: Department of Chemistry, Tarbiat Modares University, Tehran 14115-175, Iran.
authors.forename: Abolhassan
authors.initials: A
authors.lastname: Noori
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: S
authors.initials: S
authors.lastname: Zahra Bathaie
authors.affiliation: Department of Chemistry, Tarbiat Modares University, Tehran 14115-175, Iran. Electronic address: mfmousavi@yahoo.com.
authors.forename: Mir F
authors.initials: MF
authors.lastname: Mousavi
mesh_terms: D000906:Antibodies / Q000276:immunology; D052157:Aptamers, Nucleotide / Q000737:chemistry; D014408:Biomarkers, Tumor / Q000097:blood* / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation; D001943:Breast Neoplasms / Q000097:blood* / Q000175:diagnosis; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D066246:ErbB Receptors / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D005260:Female; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000906:Antibodies; D052157:Aptamers, Nucleotide; D014408:Biomarkers, Tumor; D006046:Gold; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Aptamer; Breast cancer; EGFR; Electrochemical sandwich immunosensors; Gold nanoparticles