A fluorescence method for homogeneous detection of influenza A (H1N1) DNA sequence based on Guanine(G)-quadruplex- N-methylmesoporphyrin IX (NMM) complex and Assistance-DNA (A-DNA) inhibition.

In this work, we report a fluorescence method for homogeneous detection of influenza A (H1N1) DNA sequence based on G-quadruplex-NMM complex and Assistance DNA (A-DNA) inhibition. The quadruplex-based functional DNA (QBF-DNA), composed of complementary probe to the target H1N1 DNA sequence and G-rich fragment, was designed as the signal DNA. The A-DNA consisted of two parts, one part was complementary to target H1N1 DNA and the other part was complementary to the signal DNA. In the absence of target H1N1 DNA, the G-rich fragment of QBF-DNA can form G-quadruplex-NMM complex, which outputted a fluorescent signal. With the presence of target H1N1 DNA, QBF-DNA and A-DNA can simultaneously hybridize with target H1N1 DNA to form double-helix structure. In this case, the A-DNA partially hybridized with the QBF-DNA, which inhibited the formation of G-quadruplex-NMM complex, leading to the decrease of fluorescent signal. Under the optimum conditions, the fluorescence intensity was inversely proportional to the concentration of target H1N1 DNA over the range from 25pmol/L to 700pmol/L with a detection limit of 8pmol/L. In addition, the method is target specific and practicability, and would become a new diagnostic assay for influenza A (H1N1) DNA sequence and other infectious diseases. This article is protected by copyright. All rights reserved.