Fluorescence encoding technology based tetrahedral nano-string for logic identification of breast cancer cells

Biomarkers based cancer cells discrimination plays an important role in the era of precision medicine. Single biomolecule-based cancer cells identification methods may lead to false positive results, while multiplexed and logic analysis methods have excellent accuracy and efficiency performances. In this work, a fluorescence composite coding strategy combining color and intensity was constructed with tandem shaped tetrahedral nano-string (TanTNS) as carrier and four Alexa Flour dyes as tags. More than 2⁹ TanTNS codes were built by changing the types and numbers of AF dyes loaded on TanTNS. TanTNS probes prepared by the nanostructure of TanTNS codes binding with three bio-recognition unites successfully realized the specific fluorescence imaging of two miRNAs (miRNA 21 and miRNA-31) and two membrane proteins (EpCAM and PTK-7). Multiplexed fluorescence imaging of four molecules was demonstrated in single breast cell line by using TanTNS probes. Three beast cell types were logically distinguished based on fluorescence imaging of these four TanTNS probes in the co-cultured system. To further validate the specificity results and decode the genuine spatial information of targets, an independently developed fluorescence colocalization analysis method by using MATLAB was proposed. The TanTNS probes provided brand-new tools for precision medicine, expecting to be used for clinical liquid biopsy.