Sensitive detection of DNA at the sub picomolar range is demonstrated using a magnetic bead sandwich hybridization assay coupled with surface-enhanced fluorescence (SEF)-based amplification. Unlike enzymatic amplification, the SEF amplification step does not add any additional background to the measurement and does not cause a significant increase in the coefficient of variance (CV).
Annink, C., & Gill, R. (2014). Nanoparticle Aggregate-Based Fluorescence Enhancement for Highly Sensitive and Reproducible Detection of DNA. Particle & particle systems characterization, 31(9), 943-947. https://doi.org/10.1002/ppsc.201400061