Simultaneous detection of two breast cancer-related miRNAs in tumor tissues using p19-based disposable amperometric magnetobiosensing platforms.

A novel magnetobiosensing approach for the rapid and simultaneous detection of two breast cancer-related miRs (miR-21 and miR-205) is reported. It involves the use of antimiR-21 and antimiR-205 specific probes, chitin-modified magnetic beads (Chitin-MBs), the p19 viral protein as capture bioreceptor and amperometric detection with the H2O2/hydroquinone (HQ) system at dual screen-printed carbon electrodes (SPdCEs). The use of SPdCEs allows the simultaneous independent amperometric readout for each target miR to be measured. The magnetosensor exhibited sensitive and selective detection with dynamic ranges from 2.0 to 10.0nM and detection limits of 0.6nM (6fmol) for both target miRs without any amplification step in less than 2h. The usefulness of the approach was evaluated by detecting the endogenous levels of both target miRs in total RNA (RNAt) extracted from metastatic breast cancer cell lines and human tissues.