|Name||Mr. Danté Comer|
|Organization or Institution||Department of Chemistry and Biochemistry, Florida State University|
Optimization of electrochemical aptamer-based sensor performance via controlling gold morphology
Amanda J. Ritz, Danté N. Comer, Robert A. Lazenby
Department of Chemistry and Biochemistry, Florida State University, USA
Electrochemical aptamer-based (E-AB) biosensors utilize binding-induced changes in aptamer conformation for the quantitative detection of specific analytes.1 Sensors of this type typically employ macroscale electrodes with surface-immobilized DNA, tagged with a redox reporter molecule, such as methylene blue, to provide a reagentless and reversible response to an analyte. Examples in literature aimed at reducing the size of the sensor demonstrate a direct correlation between increasing microscopic surface area of the interrogating electrode and analyte current response. Methods used to increased surface area include heat-shrinking gold surface coatings,2 electroetching gold,3 and using selectively etched gold alloys.4 In this work, electrodeposition is used to control gold morphology on the electrode surface, using both constant applied-potentials and pulsed-waveforms. The current response, probe packing density, and signal change of the resultant sensors were studied, using an E-AB sensor selective for adenosine 5’ triphosphate as a model system. The current response and aptamer probe packing density and background current are affected by the roughness of the surface of the Au-nanostructured sensors, with the surface characterized via scanning electron microscopy. The current response and signal change are characterized via square wave voltammetry while the probe packing density and electrochemical surface area are characterized via cyclic voltammetry.
1 Schoukroun-Barnes, L. R.; Macazo, F. C.; Gutierrez, B.; Lottermoser, J.; Liu, J.; White, R. J. Annu. Rev. Anal. Chem. 2016, 9, 163–181.
2 Li, S.; Lin, L.; Chang, X.; Si, Z.; Plaxco, K. W.; Khine, M.; Li, H.; Xia, F. RSC Adv. 2020, 11 (2), 671–677.
3 Arroyo-Currás, N.; Scida, K.; Ploense, K. L.; Kippin, T. E.; Plaxco, K. W. Anal. Chem. 2017, 89 (22), 12185–12191.
4 Downs, A. M.; Gerson, J.; Hossain, M. N.; Ploense, K.; Pham, M.; Kraatz, H. B.; Kippin, T.; Plaxco, K. W. ACS Sensors 2021, 6 (6), 2299–2306.