Early detection, diagnosis and treatment of human immune deficiency virus (HIV) infection is the key to reduce acquired immunodeficiency syndrome (AIDS) mortality. In our research, an innovative surface plasmon resonance (SPR) biosensing strategy has been developed for highly sensitive detection of HIV-related DNA based on entropy-driven strand displacement reactions (ESDRs) and double-layer DNA tetrahedrons (DDTs). ESDRs as enzyme-free and label-free signal amplification circuit can be specifically triggered by target DNA, leading to the cyclic utilization of target DNA and the formation of plentiful double-stranded DNA (dsDNA) products. Subsequently, the dsDNA products bind to the immobilized hairpin capture probes and further combine with DDTs nanostructures. Due to the high efficiency of ESDRs and large molecular weight of DDTs, the SPR response signal was enhanced dramatically. The proposed SPR biosensor could detect target DNA sensitively and specifically in a linear range from 1 pM to 150 nM with a detection limit of 48 fM. In addition, the whole detecting process can be accomplished in 60 min with high accuracy and duplicability. In particular, the developed SPR biosensor was successfully used to analyze target DNA in complex biological sample, indicating that the developed strategy is promising for rapid and early clinical diagnosis of HIV infection.

早期发现，诊断和治疗人类免疫缺陷病毒（HIV）感染是降低后天免疫缺陷综合症（AIDS）死亡率的关键。在我们的研究中，基于熵驱动的链置换反应（ESDR）和双层DNA四面体（DDT），开发了一种创新的表面等离子体共振（SPR）生物传感策略，用于高灵敏度检测HIV相关DNA。ESDR作为无酶和无标记的信号放大电路可以由目标DNA特异性触发，从而导致目标DNA的循环利用和大量双链DNA（dsDNA）产物的形成。随后，dsDNA产物与固定的发夹捕获探针结合，并进一步与DDT纳米结构结合。由于ESDR的高效率和DDT的大分子量，SPR响应信号大大增强。提出的SPR生物传感器可以灵敏地检测目标DNA，特别是在1 pM至150 nM的线性范围内，检测限为48 fM。另外，整个检测过程可以在60分钟内完成，具有很高的准确性和重复性。特别是，开发的SPR生物传感器已成功用于分析复杂生物样品中的目标DNA，这表明开发的策略有望对HIV感染进行快速，早期的临床诊断。