title: An Optically-Transparent Aptamer-Based Detection System for Colon Cancer Applications Using Gold Nanoparticles Electrodeposited on Indium Tin Oxide.
abstract: In this paper, a label-free aptamer based detection system (apta-DS) was investigated for detecting colon cancer cells. For this purpose, we employed an aptamer specific to colon cancer cells like HCT116 expressing carcinoembryonic antigen (CEA) on their surfaces. Capture aptamers were covalently immobilized on the surface of gold nanoparticles (GNPs) through self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA) activated with EDC (1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide)/N-hydroxysuccinimide (NHS). The cyclic voltammetry (CV) and chronopotentiometry (CP) methods were used for electrodeposition of GNPs on the surface of indium tin oxide (ITO). In this work, the CV method was also used to demonstrate the conjugation of GNPs and aptamers and identify the cancer cell capturing events. Additionally, Field Emission Scanning Electron Microscopy (FE-SEM) confirmed the deposition of GNPs on ITO and the immobilization of aptamer on the apta-DS. The electrodeposited GNPs played the role of nanoprobes for cancer cell targeting without losing the optical transparency of the ITO substrate. A conventional optical microscope also verified the detection of captured cancer cells. Based on this study's results relying on electrochemical and optical microscopic methods, the proposed apta-DS is reliable and high sensitive with a LOD equal to 6 cell/mL for colon cancer detection.
authors.affiliation: Department of Life Science Engineering, Faculty of New Sciences &amp;Technologies, University of Tehran, Tehran 14395-1561, Iran. m_ahmadzadeh@ut.ac.ir.|Department of Electrical Engineering and Computer Science, York University, Toronto, ON M3J1P3, Canada. m_ahmadzadeh@ut.ac.ir.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Ahmadzadeh-Raji
authors.affiliation: Department of Electrical Engineering and Computer Science, York University, Toronto, ON M3J1P3, Canada. egz@cse.yorku.ca.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Ghafar-Zadeh
authors.affiliation: Department of Life Science Engineering, Faculty of New Sciences &amp;Technologies, University of Tehran, Tehran 14395-1561, Iran. amoabediny@ut.ac.ir.|Department of Biotechnology and Pharmacy Engineering, Faculty of Chemical Engineering, University of Tehran, Tehran 4563-11155, Iran. amoabediny@ut.ac.ir.
authors.forename: Ghasem
authors.initials: G
authors.lastname: Amoabediny
mesh_terms: D052158:Aptamers, Peptide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D002272:Carcinoembryonic Antigen / Q000737:chemistry; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D004595:Electroplating; D006046:Gold / Q000737:chemistry*; D045325:HCT116 Cells; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D052158:Aptamers, Peptide; D002272:Carcinoembryonic Antigen; D017971:Tin Compounds; C109984:indium tin oxide; D006046:Gold
keywords: Gold Nanoparticle (GNP); apta-DS; chronopotentiometry (CP); colon cancer; cyclic voltammetry (CV); indium tin oxide (ITO)