DNA specificity detection with high discrimination performance in silver nanoparticle coupled directional fluorescence spectrometry

A new method for DNA specificity detection with high discrimination performance is established based on a novel silver nanoparticle coupled surface plasmon-coupled emission strategy (AgNPs coupled SPCE). This strategy is designed to overcome some limitations in traditional DNA interfacial detection. According to the designed hybridization assembly, target DNA causes configuration change of molecular beacon probe and triggers the assembly of AgNPs on SPCE gold film, forming a nanometer interstice. Under excitation state, this AgNPs-gold film nanostructure has intense hot spot effect, which effectively arouses the fluorophores within it. While the AgNPs assembly process is effectively blocked when single base mismatching target is detected, resulting no fluorescence recovery from the quenching state. The typical performances of AgNPs coupled SPCE have been demonstrated. In comparison with traditional DNA interfacial detection method based on SPCE, this novel strategy is proved to enhance the potential signal readout while suppressing the false positive signal. It offers a 67-fold signal to background ratio, and more than 25-fold discriminating ability for mismatch detection is achieved. The discrimination ratios between complementary target and mismatch target are about 10 times as much as those in traditional method. The proposed AgNPs coupled SPCE is applied to DNA mismatch discrimination in serum samples. In brief, this AgNPs coupled SPCE strategy provides an effective method for DNA interfacial detection. (C) 2017 Elsevier B.V. All rights reserved.