An innovative strategy for direct electrochemical detection of microRNA biomarkers

• Published in: Analytical and bioanalytical chemistry Vol. 406; no. 4; pp. 1241 - 1244
• Main Authors: Tran, H. V., Piro, B., Reisberg, S., Anquetin, G., Duc, H. T., Pham, M. C.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-02-2014; Springer; Springer Nature B.V
• Subjects: Acids; Affinity; Analysis; Analytical Chemistry; Biochemistry; Biological markers; Biomarkers; Biomarkers - chemistry; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Copolymers; Electrochemistry; Electrodes; Electrons; Food Science; Hybridization; Laboratory Medicine; Mathematical analysis; MicroRNA; MicroRNAs; MicroRNAs - chemistry; MicroRNAs - genetics; Molecular biology; Monitoring/Environmental Analysis; Nucleic Acid Hybridization; Oligonucleotides; Ribonucleic acids; Sensors; Strategy; Transducers; Voltammetry; France; microRNA; Direct detection; Square wave voltammetry; Electrochemical biosensor; Label-free detection
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-013-7292-4

We report an electrochemical method for direct, reagentless, and label-free detection of microRNA, based on a conjugated copolymer, poly(5-hydroxy-1,4-naphthoquinone-co-5-hydroxy-2-carboxyethyl-1,4-naphthoquinone), acting as hybridization transducer. Hybridization between the oligonucleotide capture probe and a microRNA target of 22 base pairs generates an increase in the redox current (“signal-on”), which is evidenced by square wave voltammetry. Selectivity is good, with little hybridization for non-complementary targets, and the limit of detection reaches 650 fM. It is also evidenced that this sensitivity benefits from the high affinity of DNA for RNA.
Figure
The biosensor gives a current increase (signal-on) upon miRNA addition. It was shown that miRNAs give better sensitivity than corresponding DNAs.