West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, 610041, PR China.
Precision Medicine Translational Research Center, Medical Equipment Innovation Research Center, Med-X Center for Manufacturing, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, PR China.
Biosens Bioelectron. 2024 Nov 1;263:116615. doi: 10.1016/j.bios.2024.116615. Epub 2024 Jul 30.
Circulating tumor DNA (ctDNA) is an emerging biomarker of liquid biopsy for cancer. But it remains a challenge to achieve simple, sensitive and specific detection of ctDNA because of low abundance and single-base mutation. In this work, an excitation/emission-enhanced heterostructure photonic crystal (PC) array synergizing with entropy-driven circuit (EDC) was developed for high-resolution and ultrasensitive analysis of ctDNA. The donor donor-acceptor FÖrster resonance energy transfer ("DD-A" FRET) was integrated in EDC based on the introduction of simple auxiliary strand, which exhibited higher sensitivity than that of traditional EDC. The heterostructure PC array was constructed with the bilayer periodic nanostructures of nanospheres. Because the heterostructure PC has the adjustable dual photonic band gaps (PBGs) by changing nanosphere sizes, and the "DD-A" FRET can offer the excitation and emission peak with enough distance, it helps the successful matches between the dual PBGs of heterostructure PC and the excitation/emission peaks of "DD-A" FRET; thus, the fluorescence from EDC can be enhanced effectively from both of excitation and emission processes on heterostructure PC array. Besides, high-resolution of single-base mutation was obtained through the strict recognition of EDC. Benefiting from the specific spectrum-matched and synergetic amplification of heterostructure PC and EDC with "DD-A" FRET, the proposed array obtained ultrasensitive detection of ctDNA with LOD of 12.9 fM, and achieved the analysis of mutation frequency as low as 0.01%. Therefore, the proposed strategy has the advantages of simple operation, mild conditions (enzyme-free and isothermal), high-sensitivity, high-resolution and high-throughput analysis, showing potential in bioassay and clinical application.
循环肿瘤 DNA（ctDNA）是液体活检癌症的新兴生物标志物。但是，由于 ctDNA 丰度低和单碱基突变，实现 ctDNA 的简单、敏感和特异性检测仍然是一个挑战。在这项工作中，开发了一种激发/发射增强的异质光子晶体（PC）阵列与熵驱动电路（EDC）协同作用，用于 ctDNA 的高分辨率和超灵敏分析。基于简单辅助链的引入，将供体-受体Förster 共振能量转移（“DD-A” FRET）集成到 EDC 中，其灵敏度比传统 EDC 更高。异质结构 PC 阵列由双层周期性纳米结构的纳米球构成。由于异质结构 PC 通过改变纳米球尺寸具有可调的双光子带隙（PBG），并且“DD-A” FRET 可以提供足够距离的激发和发射峰，因此有助于异质结构 PC 的双 PBG 与“DD-A” FRET 的激发/发射峰之间的成功匹配；因此，可以从异质结构 PC 阵列的激发和发射过程有效地增强来自 EDC 的荧光。此外，通过 EDC 的严格识别实现了单碱基突变的高分辨率。受益于“DD-A” FRET 的异质结构 PC 和 EDC 的特定光谱匹配和协同放大，所提出的阵列获得了对 ctDNA 的超灵敏检测，LOD 为 12.9 fM，并实现了低至 0.01%的突变频率分析。因此，该策略具有操作简单、条件温和（无酶和等温）、高灵敏度、高分辨率和高通量分析的优点，在生物测定和临床应用中具有潜力。
