In this work, an enzyme-free fluorescence resonance energy transfer (FRET) strategy was established for rapid and specific detection of the DNA sequence from Vibrio parahaemolyticus (VP) using hybridization chain reaction (HCR) amplification and triplex DNA. The triplex forming oligonucleotide (TFO) was labelled with carboxyfluorescein (FAM) as fluorescence donor, and hairpin sequence H1 was labelled by tetramethylrhodamine (TAMRA) as fluorescence receptor. In the present target VP DNA, the hairpin structure of molecular beacon (MB) was opened, the free end was released and hybridized with H1-TAMRA, and the HCR reaction was triggered by the alternate supplementation of H1-TAMRA and H2 to produce the notch double helix analogue. After the addition of TFO-FAM, a triplex structure was formed between HCR products (H1-TAMRA/H2) and TFO-FAM. A close contact between the donor and the receptor resulted in FRET. Under the optimal conditions, the fluorescence quenching value was inversely proportional to the concentration of target VP DNA in the range of 0.1–50 nmol L⁻¹, and the detection limit was 35 pmol L⁻¹.

在这项工作中，建立了一种无酶荧光共振能量转移（FRET）策略，用于快速，特异性地检测副溶血性弧菌的DNA序列。（VP）使用杂交链反应（HCR）扩增和三链DNA。用羧基荧光素（FAM）作为荧光供体标记形成三链体的寡核苷酸（TFO），并用四甲基罗丹明（TAMRA）作为荧光受体标记发夹序列H1。在本靶标VP DNA中，打开分子信标（MB）的发夹结构，释放自由端并与H1-TAMRA杂交，并通过交替添加H1-TAMRA和H2触发HCR反应以产生缺口双螺旋类似物。加入TFO-FAM之后，HCR产物（H1-TAMRA / H2）和TFO-FAM之间形成了三重结构。供体和受体之间的紧密接触导致FRET。在最佳条件下^-1，检出限为35 pmol L ^-1。