title: Reduced graphene oxide decorated with gold nanoparticle as signal amplification element on ultra-sensitive electrochemiluminescence determination of caspase-3 activity and apoptosis using peptide based biosensor.
abstract: Introduction:Growing demands for ultrasensitive biosensing have led to the development of numerous signal amplification strategies. In this report, a novel electrochemiluminescence (ECL) method was developed for the detection and determination of caspase-3 activity based on reduced graphene oxide sheets decorated by gold nanoparticles as signal amplification element and horseradish peroxidase enzyme (HRP) as ECL intensity enhancing agent.Methods:The ECL intensity of the luminol was improved by using the streptavidin coated magnetic beads and HRP in the presence of hydrogen peroxide. The cleavage behavior of caspase-3 was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques using biotinylated peptide (DEVD containing peptide) which was coated on reduced graphene oxide decorated with gold nanoparticle. The surface modification of graphene oxide was successfully confirmed by FTIR, UV-vis and x-ray spectroscopy.Results:ECL based biosensor showed that the linear dynamic range (LDR) and the lower limit of quantification (LLOQ) were 0.5-100 and 0.5 femtomolar (fM), respectively. Finally, the performance of the engineered peptide based biosensor was validated in the A549 cell line as real samples.Conclusion:The prepared peptide based biosensor could be considered as an excellent candidate for early detection of apoptosis, cell turnover, and cancer related diseases.
authors.affiliation: Research Center for Pharmaceutical Nanotechnology (RCPN), Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Balal
authors.initials: B
authors.lastname: Khalilzadeh
authors.affiliation: Department of Nanochemistry and Nanotechnology Center, Urmia University, Urmia, Iran.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Shadjou
authors.affiliation: Research Center for Pharmaceutical Nanotechnology (RCPN), Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Afsharan
authors.affiliation: Research Center for Pharmaceutical Nanotechnology (RCPN), Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Morteza
authors.initials: M
authors.lastname: Eskandani
authors.affiliation: Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran ; Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hojjatollah
authors.initials: H
authors.lastname: Nozad Charoudeh
authors.affiliation: Research Center for Pharmaceutical Nanotechnology (RCPN), Tabriz University of Medical Sciences, Tabriz, Iran ; Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Rashidi
keywords: Apoptosis; Caspase-3; DEVD-peptide; Electrochemiluminescence; Gold nanoparticle; Reduced graphene oxide