Molecular Beacon Nano-Sensors for Probing Living Cancer Cells

Precisely controlling the dose of MBs delivered into live cells, which allows quantitative analysis at single-cell resolution, is becoming increasingly feasible. The design of MBs is moving towards increased sensitivity and longer-lasting resistance to nucleases and other enzymes. The 'specificity' parameter is particularly important for prognostic bio-chips and in vivo imaging. MB designs that address single-nucleotide mutations and that can detect multiple targets are becoming popular. Heterogeneities and oncogenesis essentially result from proteomic disorders orchestrated by changes in DNA and/or cytoplasmic mRNA. These genetic fluctuations, however, cannot be decoded through conventional label-free methods (e.g., patch clamps, electrochemical cellular biosensors, etc.) or morphological characterization. Molecular beacons (MBs) have recently emerged as efficient probes for interrogating biomarkers in live cancer cells. MBs hybridize with their intracellular targets (e.g., mRNAs, DNAs, or proteins), emitting a fluorescent signal that can be quantified and correlated with the expression levels of their targets. In this review we discuss MB probes with different delivery platforms for intracellular probing as well as novel MB designs for detecting a variety of targets in living cancer cells. Finally, we describe current trends in MB-based intracellular biosensors. Heterogeneities and oncogenesis essentially result from proteomic disorders orchestrated by changes in DNA and/or cytoplasmic mRNA. These genetic fluctuations, however, cannot be decoded through conventional label-free methods (e.g., patch clamps, electrochemical cellular biosensors, etc.) or morphological characterization. Molecular beacons (MBs) have recently emerged as efficient probes for interrogating biomarkers in live cancer cells. MBs hybridize with their intracellular targets (e.g., mRNAs, DNAs, or proteins), emitting a fluorescent signal that can be quantified and correlated with the expression levels of their targets. In this review we discuss MB probes with different delivery platforms for intracellular probing as well as novel MB designs for detecting a variety of targets in living cancer cells. Finally, we describe current trends in MB-based intracellular biosensors.