Multiplex signal cascade fluorescent biosensing for single nucleotide polymorphisms enhanced detection

Glioma seriously endangers human lives and health, and precise SNPs genotyping is the key to modern clinical theranostics. A single nucleic acid signal amplification strategy cannot effectively ensure sensitivity and specificity detection. Herein, a multiplex signal amplification platform based on collaborative chain reaction (LCR, HCR) and cascaded rolling circle reaction (RCA) was first presented for specific and sensitive single nucleotide polymorphisms (SNPs) enhanced genotyping. The elongation HCR products were G-quadruplex and enriched on the magnetic nanoparticles (MBs). As the fluorescent intercalator, the thioflavin T (ThT) ligand was significantly embedded G-quadruplex structure for fluorescence enhancement, to indicate the mutation occurrence. Making use of the multiplex signal amplification strategy, as low as 1×10 mol/L mutated strands can be detected, and the allele frequency determined was accurately achieved at 0.5%, indicating high sensitivity and high fidelity. Furthermore, this portable LCR-HCR-RCA multiplex signal cascade fluorescent biosensing (LHRCA) was combined with the efficient enrichment and rapid separation of magnetic nanoparticles (MBs), and suitable for glioma cell lysate samples analysis, making it a promising candidate for disease-associated SNPs discrimination.