Development of an Electrochemical Impedimetric Biosensor for the Detection of Telomerase Activity in Cancer Cells

Wednesday, 31 May 2017: 14:40
Grand Salon A - Section 4 (Hilton New Orleans Riverside)
C. R. Cabrera Jr. (University of Puerto RIco at Río Piedras), D. C. Diaz-Cartagena, G. Hernandez (University of Puerto Rico at Río Piedras), L. Cunci Perez (Universidad del Turabo), and C. I. Gonzalez (Universiy of Puerto Rico at Río Piedras)
Developing novel strategies to effectively detect biomarkers is of utmost importance in the early detection of cancer cells to increase the chances of a successful therapy. The proposed biosensor microchips works by tethering a biomolecular probe on the interdigital gold electrode array surfaces. This biomolecule probe can be customized according to the target biomarker, in order to recognize the change of conformation or bond upon contact. Telomerase is an enzyme responsible for the elongation of the telomeres between each cell division, restoring their length and avoiding cell death. This enzyme is responsible for the immortalization of cancer cells and it consists of a reverse transcriptase bound to a single stranded RNA (ssRNA) that is used as a template for telomere lengthening. The innovative research proposed in this project takes advantage of the telomerase and its ssRNA template by tethering a telomere-like ssDNA biomolecule probe that consists of a spacer composed of ten thymine, and the repeating sequence present in the telomeres of eukaryotic cells, 5’-TTAGGG-3’. The telomerase binds and elongates the probe, blocking electronic and capacitive processes on the microelectrode array surfaces. This change is detected by measuring the impedance using electrochemical impedance spectroscopy, which is correlated to the activity of telomerase and the presence of cancer cells. Moreover, telomerase is currently the target of many pharmaceutical companies to block cancer cell proliferation due to its presence in ca. 85% of known cancer cells (e.g. prostate, breast, and colorectal cancers). This project provides a unique opportunity to study the surface chemistry, impedance sensing, detection limits, and robustness of this microchip technology for its possible use at the point-of-care. This is funded by NSF Grant titled "Label-Free Electrochemical Capacitance DNA Sensing with Passive Wireless Radio Frequency Identification Sensor Technology" CHE-1152940.