Quantitative Electrochemical DNA Microarray on a Monolith Electrode with Ten Attomolar Sensitivity, 100% Specificity, and Zero Background

Authors

• Shobana Raghunath, Vajra Instruments
• Abhijeet Prasad, Vajra Instruments & University of Nebraska LincolnFollow
• Rahul Tevatia, University of Nebraska-LincolnFollow
• Jillian R. Gunther, MD Anderson Cancer Research Center Houston
• Santanu Roy, Vajra Instruments
• Sunil Krishnan, MD Anderson Cancer Research Center Houston
• Ravi Saraf, University of Nebraska-LincolnFollow

Date of this Version

5-29-2019

Document Type

Article

Citation

2018 Wiley-VCH GmbH & Co. KGaA, Weinheim

Comments

ChemElectroChem. 2018 February 1; 5(3): 429–433. doi:10.1002/celc.201700983

Abstract

Circulating microRNA are promising diagnostic and prognostic biomarkers of disease in quantitative blood tests. A label-free, PCR-free, electrochemical microarray technology on a monolith electrode is described, with 10 attomolar (aM) sensitivity and responsiveness to binding of <1 zeptomole of target to immobilized ssDNA probes with zero background. Specificity is 100% in a mixture with five nonspecific miRNA each with a 103-fold higher concentration. Direct measurement on plasma-derived miRNA without cDNA conversion and PCR demonstrated multiplexing and near-ideal quantitative correlation with an equivalent pure sample. The dynamic range is a target concentration ranging from 10–2 to 103 femtomolar (fM). This PCR-free novel technology can be applied as a test for cancer diagnosis/prognosis to detect 103 copies of a miRNA sequence in RNA extracted from 100 μL of plasma.