Quantitative Detection of MicroRNA in One Step via Next Generation Magnetic Relaxation Switch Sensing

Abstract

One-step, quantitative and rapid detection of microRNA (miRNA) in tumor cells or tissues can provide critical information for clinical diagnosis and cancer treatment. In this work, we develop a magnetic relaxation switch sensing (MRS)-based miRNA sensor using magnetic microparticle (1 μm in diameter, MM1000)-DNA probe-magnetic nanoparticle (30 nm in diameter, MN30) conjugates (MM1000-DNA-MN30). In the presence of target miRNA, DSN enzyme selectively cleaves the DNA tether after miRNA/DNA hybridization to release MN30 and leaves the miRNA intact to lead to the declustering of more MN30 than before. In contrast to conventional MRS by measuring the change of transverse relaxation time (ΔT2) induced by the aggregation or dissociation of magnetic particles in the presence of target, we use the cleaved MN30 from conjugates as the direct readout of ΔT2, which is more sensitive and stable. This MRS-based assay allows for one-step detection of 5 fM of miR-21 in urine samples, quantification of miR-21 from 100 cancer cells, and differentiation of the expression of miR-21 in tumor and surrounding tissues. The merits of this assay, rapidity, ability for quantitation, high sensitivity, and one-step operation, ensure a promising future in diagnostic technology.

Application of Isothermal Nucleic Acid Signal Amplification in the Detection of Hepatocellular Carcinoma‐Associated MicroRNA

“…Lu et al. (2016) developed a one‐step DSN‐assisted amplification strategy by means of magnetic relaxation switch sensing (Figure ) . They synthesized a magnetic nanoparticle‐DNA probe‐magnetic microparticle conjugates.…”

Increasing the sensitivity and selectivity of a GONS quenched probe for an mRNA assay assisted with duplex specific nuclease

“…It has been reported that the existence of mismatch base pair in the duplex can signicantly reduce the efficiency of DSN digestion. 30 We also found that the uorescence signal caused by mT1 and mT2 was only 50%, 25% of that by T1, nearly no uorescence increase was observed for mT3 aer introducing DSN for the assay (Fig. 5).…”

“…To optimize the reaction time between DNA/mRNA hybrid and DSN, 1 mL of the probe solution (100 nM), T1 (20 nM) and 1 mL DSN solution (0.2 units) were mixed in the 47 mL buffer. The mixture solutions were incubated for 0, 5,10,15,20,25,30,35 and 40 min at 45 C, respectively. Then, 2.7 mg GONS was added.…”

Advances in the Application of Magnetic Nanoparticles for Sensing

“…This has been achieved with magnetic relaxation switches using duplex-specific nuclease enzymes and DNA complexed to both 30 nm and 1000 nm MNPs. [187] In the presence of the target miRNA, a DNA-RNA duplex is formed and then cleaved by the duplex-specific nuclease enzymes to release the 30 nm MNP. The decrease in magnetic size increases the T 2…”