A SERS-based lateral flow assay biosensor for highly sensitive detection of HIV-1 DNA

User-friendly lateral flow (LF) strips have been extensively used for point-of-care (POC) self-diagnostics, but they have some limitations in their detection sensitivity and quantitative analysis because they only identify the high cut-off value of a biomarker by utilizing color changes that are detected with the naked eye. To resolve these problems associated with LF strips, we developed a novel surface-enhanced Raman scattering (SERS)-based LF assay for the quantitative analysis of a specific biomarker in the low concentration range. Herein, human immunodeficiency virus type 1 (HIV-1) DNA was chosen as the specific biomarker. Raman reporter-labeled gold nanoparticles (AuNPs) were employed as SERS nano tags for targeting and detecting the HIV-1 DNA marker, as opposed to using bare AuNPs in LF strips. It was possible to quantitatively analyze HIV-1 DNA with high sensitivity by monitoring the characteristic Raman peak intensity of the DNA-conjugated AuNPs. Under optimized conditions, the detection limit of our SERS-based lateral flow assay was 0.24 pg/mL, which was at least 1000 times more sensitive compared to colorimetric or fluorescent detection methods. These results demonstrate the potential feasibility of the proposed SERS-based lateral flow assay to quantitatively detect a broad range of genetic diseases with high sensitivity.

用户友好的侧流 (LF) 试纸条已广泛用于即时护理 (POC) 自我诊断，但它们在检测灵敏度和定量分析方面存在一些局限性，因为它们仅通过利用肉眼检测到的颜色变化来识别生物标志物的高截止值。为了解决与 LF 试纸条相关的这些问题，我们开发了一种新型的基于表面增强拉曼散射 (SERS) 的 LF 测定，用于低浓度范围内的特定生物标志物的定量分析。在此，选择人类免疫缺陷病毒1型（HIV-1）DNA作为特异性生物标志物。拉曼报告标记的金纳米粒子 (AuNP) 被用作 SERS 纳米标签，用于靶向和检测 HIV-1 DNA 标记，而不是在 LF 条带中使用裸 AuNP。通过监测 DNA 结合的 AuNP 的特征拉曼峰强度，可以高灵敏度地定量分析 HIV-1 DNA。在优化条件下，我们基于 SERS 的侧流检测的检测限为 0.24 pg/mL，与比色或荧光检测方法相比，其灵敏度至少高 1000 倍。这些结果证明了所提出的基于 SERS 的侧流检测具有高灵敏度定量检测广泛遗传疾病的潜在可行性。