Protein electrocatalysis for direct sensing of circulating microRNAs

Mahmoud Labib, Nasrin Khan, Maxim V. Berezovski*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


MicroRNAs (miRNAs) are potentially useful biomarkers for diagnosis, classification, and prognosis of many diseases, including cancer. Herein, we developed a protein-facilitated electrocatalytic quadroprobe sensor (SensPEQ) for detection of miRNA signature of chronic lymphocytic leukemia (CLL) in human serum. The developed signal-ON sensor provides a compatible combination of two DNA adaptor strands modified with four methylene blue molecules and electrocatalysis using glucose oxidase in order to enhance the overall signal gain. This enhanced sensitivity provided the response necessary to detect the low-abundant serum miRNAs without preamplification. The developed SensPEQ is exquisitely sensitive to subtle π-stack perturbations and capable of distinguishing single base mismatches in the target miRNA. Furthermore, the developed sensor was employed for profiling of three endogenous miRNAs characteristic to CLL, including hsa-miR-16-5p, hsa-miR-21-5p, and hsa-miR-150-5p in normal healthy serum, chronic lymphocytic leukemia Rai stage 1 (CLL-1), and stage 3 (CLL-3) sera, using a non-human cel-miR-39-3p as an internal standard. The sensor results were verified by conventional SYBR green-based quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis.

Original languageEnglish (US)
Pages (from-to)1395-1403
Number of pages9
JournalAnalytical Chemistry
Issue number2
StatePublished - Jan 20 2015
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry


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