Serum levels of leukocyte cell-derived chemotaxin-2 (LECT2) have emerged as promising diagnostic biomarker for liver fibrosis. Targeting the LECT2/Tie1 signaling pathway holds potential for innovative treatment approaches to this condition. Despite this, the development of highly sensitive assays for serum LECT2 remains limited. Surface plasmon resonance (SPR), a label-free technique for detecting biomolecular interactions via refractive index (RI) changes, has demonstrated notable sensitivity for biomarker assays, though improving its sensitivity for direct LECT2 detection faces certain challenges. In this study, we present an innovative enhanced SPR biosensor designed to overcome current limitations in LECT2 detection. By incorporating molybdenum disulfide (MoS₂) nanosheets as nano-spacer between the gold film and cyclodextrin functionalized-gold nanoparticles (CD-AuNPs), this gap-mode design significantly enhances the electric field intensity near the gold film surface, which effectively improves the detection sensitivity of the RI changes. Compared to traditional gold-film-only SPR sensors, our sensor achieves a remarkable sensitivity increase from 73.1 to 133.3 deg/RIU, with a commendable quality factor and detection accuracy. By further modifying the specific peptide of the terminal label phenylalanine (TFF) through the host-guest recognition effect of the CD hydrophobic cavity, we achieved a broad linear range and a low limit of detection (LOD = 0.6206 ng/mL) for the detection of the liver fibrosis marker LECT2. Our proposed enhanced SPR sensing platform demonstrates significant potential for clinical applications in LECT2 detection.

中文翻译：

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MoS2 介导的间隙模式表面等离子体增强：用于直接检测 LECT2 的 SPR 生物传感器的构建


白细胞来源的趋化因子-2 （LECT2） 的血清水平已成为肝纤维化的有前途的诊断生物标志物。靶向 LECT2/Tie1 信号通路具有针对该病症的创新治疗方法的潜力。尽管如此，血清 LECT2 的高灵敏度检测方法的发展仍然有限。表面等离子体共振 （SPR） 是一种通过折射率 （RI） 变化检测生物分子相互作用的无标记技术，已显示出对生物标志物检测的显著敏感性，尽管提高其对直接 LECT2 检测的灵敏度面临一定的挑战。在这项研究中，我们提出了一种创新的增强型 SPR 生物传感器，旨在克服 LECT2 检测的当前限制。通过将二硫化钼 （MoS₂） 纳米片作为金膜和环糊精功能化金纳米颗粒 （CD-AuNPs） 之间的纳米间隔物，这种间隙模式设计显着增强了金膜表面附近的电场强度，从而有效提高了 RI 变化的检测灵敏度。与传统的纯金膜 SPR 传感器相比，我们的传感器实现了从 73.1 度/RIU 到 133.3 度/RIU 的显著灵敏度提升，具有值得称道的品质因数和检测精度。通过 CD 疏水腔的主客体识别作用进一步修饰末端标记苯丙氨酸 （TFF） 的特异性肽，我们实现了较宽的线性范围和较低的检测限 （LOD = 0.6206 ng/mL） 肝纤维化标志物 LECT2。我们提出的增强型 SPR 传感平台在 LECT2 检测中展示了临床应用的巨大潜力。