Ultrasensitive electrochemical aptasensor based on sandwich architecture for selective label-free detection of colorectal cancer (CT26) cells.
Colorectal cancer is one of the most common cancers in the world and has no effective treatment. Therefore, development of new methods for early diagnosis is instantly required. Biological recognition probes such as synthetic receptor and aptamer is one of the candidate recognition layers to detect important biomolecules. In this work, an electrochemical aptasensor was developed by fabricating an aptamer-cell-aptamer sandwich architecture on an SBA-15-3-aminopropyltriethoxysilane (SBA-15-pr-NH2) and Au nanoparticles (AuNPs) modified graphite screen printed electrode (GSPE) surface for the selective, label-free detection of CT26 cancer cells. Based on the incubation of the thiolated aptamer with CT26 cells, the electron-transfer resistance of Fe (CN)63-/4- redox couple increased considerably on the aptasensor surface. The results obtained from cyclic voltammetry and electrochemical impedance spectroscopy studies showed that the fabricated aptasensor can specifically identify CT26 cells in the concentration ranges of 10-1.0×105cells/mL and 1.0×105-6.0×106 cells/mL, respectively, with a detection limit of 2cells/mL. Applying the thiol terminated aptamer (5TR1) as a recognition layer led to a sensor with high affinity for CT26 cancer cells, compared to control cancer cells of AGS cells, VERO Cells, PC3 cells and SKOV-3 cells. Therefore a simple, rapid, label free, inexpensive, excellent, sensitive and selective electrochemical aptasensor based on sandwich architecture was developed for detection of CT26 Cells.
['Hashkavayi|Ayemeh Bagheri|AB|', 'Raoof|Jahan Bakhsh|JB|', 'Ojani|Reza|R|', 'Kavoosian|Saeid|S|']
D000818:Animals D052157:Aptamers, Nucleotide D015374:Biosensing Techniques D045744:Cell Line, Tumor D002522:Chlorocebus aethiops D003106:Colon D015179:Colorectal Neoplasms D058266:Dielectric Spectroscopy D055664:Electrochemical Techniques D004566:Electrodes D006046:Gold D006108:Graphite D006801:Humans D053768:Metal Nanoparticles D051379:Mice D012007:Rectum D012680:Sensitivity and Specificity D014709:Vero Cells
Aptasensor Sandwich architecture Colorectal cancer Au nanoparticles Graphite screen printed electrode