An elevated level of homocysteine (Hcy) in serum is closely related to the development of various diseases. Therefore, homocysteine has been widely employed as a biomarker in medical diagnosis and the on-site detection of homocysteine is highly desired. In this study, a truncated highly specific aptamer for homocysteine was screened and used to design a lateral flow strip (LFS) for the detection of homocysteine. The aptamer was derived from a previously reported sequence. Based on the result of molecular docking, the original sequence was subjected to truncation, resulting in a reduction of the length from 66 nt to 55 nt. Based on the truncated aptamer, the LFS was designed for the detection of homocysteine. In the presence of homocysteine, the aptamer selectively binds to it, releasing cDNA from the aptamer/cDNA duplex. This allows cDNA to bind to the capture probe immobilized on the T zone of the strip, resulting in a red signal on the T zone from gold nanoparticles (AuNPs). The strip enables the visual detection of homocysteine in 5 min. Quantitative detection can be facilitated with the aid of ImageJ software. In this mode, the linear detection range for homocysteine is within 5–50 μM, with a detection limit of 4.18 μM. The strip has been effectively utilized for the detection of homocysteine in human serum. Consequently, the combination of the truncated aptamer and the strip offers a method that is sensitive, quick, and economical for the on-site detection of homocysteine.

中文翻译：

---

基于截短适体的同型半胱氨酸现场检测侧流试纸条

血清中同型半胱氨酸（Hcy）水平升高与多种疾病的发生密切相关。因此，同型半胱氨酸已广泛用作医学诊断中的生物标志物，并且非常需要对同型半胱氨酸进行现场检测。在本研究中，筛选了同型半胱氨酸的截短高度特异性适体，并用于设计用于检测同型半胱氨酸的侧流试纸条（LFS）。该适体源自先前报道的序列。根据分子对接结果，对原始序列进行了截短，长度从66nt缩短至55nt。基于截短适体，LFS 被设计用于同型半胱氨酸的检测。在同型半胱氨酸存在的情况下，适体选择性与其结合，从适体/cDNA 双链体中释放 cDNA。这使得 cDNA 能够与固定在试纸条 T 区上的捕获探针结合，从而在 T 区上产生来自金纳米粒子 (AuNP) 的红色信号。该试纸条可在 5 分钟内目视检测同型半胱氨酸。借助 ImageJ 软件可以促进定量检测。在此模式下，同型半胱氨酸的线性检测范围为 5–50 μM，检测限为 4.18 μM。该试纸已有效用于检测人血清中的同型半胱氨酸。因此，截短适体和试纸条的组合为同型半胱氨酸的现场检测提供了一种灵敏、快速且经济的方法。