A highly sensitive and specific fluorescent strategy for the detection of Visfatin based on nonlinear hybridization chain reaction

This study established a nonlinear hybridization chain reaction system in which trigger DNA initiates self-sustained assembly of double-stranded hairpin substrates labelled with Sulfo-Cyanine3 (Cy-3) into fluorescent dendritic nanostructures for visfatin detection. The trigger DNA chain initially bound with the anti-visfatin aptamer will be freed with visfatin, which induces continuous chain branching growth and results in an expo-nential increase in fluorescence signals. Under optimal conditions, the fluorescence intensity increased linearly with visfatin concentrations ranging from 1 ng mL-1 to 100 ng mL-1 (the limit of detection dropped to 0.028 ng mL-1). Furthermore, our study showed that magnetic bead separation minimizes the nonspecific signal of the method. The specificity, stability, and sensitivity of this method were also tested in the study. The results revealed excellent specificity, stability and sensitivity. In the aspect of application evaluation, we tested visfatin in clinical serum samples and obtained credible and accordant results so we suppose that our detection method might have bright prospects in biological molecule technology and early clinical discovery of type 2 diabetes (T2DM).