Electronic Detection of Micro RNA Mir2O6 with Molecularly-Differentiated Nanoelectrodes

Micro RNAs (miRNAs) play important roles in gene regulation at the translational level. However up to this date, there still lacks a fast and efficient method for its detection and quantification. In this paper, we present the construction and characterization of a nanoelectrode sensor array capable of detecting the presence of micro RNA (miRNA) molecules and directly converting their hybridization with an immobilized probe into an electrical signal. Each sensing unit in the array consists of three nano-scale electrodes: counter, control, and working. Electrochemical desorption is used to program the attachment of DNA oligonucleotides complementary to the target miRNA on the working electrode and a nonfouling poly(ethyleneglycol) (PEG) terminated molecular monolayer on the control and counter electrodes. The current flowing between the electrodes is monitored and the capture and hybridization of the target miRNA is verified via measurement of the differential conductance signals.