Femtomolar oligonucleotide detection by a one-step gold nanoparticle-based assay

This work presents a single-step, sequence-specific oligonucleotide detection method based on tail-to-tail aggregation of functionalized gold nanoparticles in the presence of target analytes. Using cost-effective instrumentation and the corresponding simplified analysis, the optimized assay has a 10 fM limit of detection and dynamic range up to nM analyte concentration. The detection of perfect match sequences were three orders of magnitude more sensitive than targets with single nucleotide mismatches.