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Dual-Reporter Drift Correction To Enhance the Performance of Electrochemical Aptamer-Based Sensors in Whole Blood

Li, Hui, Arroyo-Currás, Netzahualcóyotl, Kang, Di, Ricci, Francesco, Plaxco, Kevin W.
Journal of the American Chemical Society 2016 v.138 no.49 pp. 15809-15812
blood serum, electrochemistry, monitoring, oligonucleotides, redox potential
The continuous, real-time monitoring of specific molecular targets in unprocessed clinical samples would enable many transformative medical applications. Electrochemical aptamer-based (E-AB) sensors appear to be a promising approach to this end because of their selectivity (performance in complex samples, such as serum) and reversible, single-step operation. E-AB sensors suffer, however, from often-severe baseline drift when challenged in undiluted whole blood. In response we report here a dual-reporter approach to performing E-AB baseline drift correction. The approach incorporates two redox reporters on the aptamer, one of which serves as the target-responsive sensor and the other, which reports at a distinct, nonoverlapping redox potential, serving as a drift-correcting reference. Taking the difference in their relative signals largely eliminates the drift observed for these sensors in flowing, undiluted whole blood, reducing drift of up to 50% to less than 2% over many hours of continuous operation under these challenging conditions.