Rolling Circle Amplification-Based Polyvalent Molecular Beacon Probe-Assisted Signal Amplification Strategies for Sensitive Detection of B16 Cells.

We developed a simple and sensitive signal amplification method for the detection of B16 cells based on the combination of rolling circle amplification (RCA) and molecular beacons (MBs). A long-chain structure of DNA synthesized by RCA was used to turn on aptamer-based MBs. Because of the multiple complementary repeat units, the RCA scaffold hybridized tens or hundreds of MBs to form polyvalent aptamer probes. The unfold ability and the fluorescence intensity of MBs were both improved by RCA, as compared to short single chains. The cell experiment results demonstrated that RCA-based polyvalent MBs were significantly more effective than monovalent MBs in targeting B16 cells and signal sensitivity because of their multivalent effects. The establishment of this strategy would provide a powerful platform for early clinical diagnostics of cancer cells.