We validated a single-stranded, DNA aptamer-based, diagnostic method capable of detecting Lipocalin-2 (LCN2), a biomarker from clinically relevant hepatocellular carcinoma (HCC) patient serum, in the sandwich assay format. Nine aptamers (LCN2_apta1 to LCN2_apta9) for LCN2 were screened with SELEX processes, and a sandwich pair (LCN2_apta2 and LCN2_apta4) was finally chosen using surface plasmon resonance (SPR) and dot blotting analysis. The result of the proposed aptamer sandwich construction shows that LCN2 was sensitively detected in the concentration range of 2.5-500 ng mL(-1) with a limit of detection of 0.6 ng mL(-1). Quantitative measurement tests in HCC patients were run on straight serum and were compared with the performance of the conventional antibody-based ELISA kit. The aptamer sandwich assay demonstrated an excellent dynamic range for LCN2 at clinically relevant serum levels, covering sub-nanogram per mL concentrations. The new approach offers a simple and robust method for detecting serum biomarkers that have low and moderate abundance. It consists of functionalization, hybridization and signal read-out, and no dilution is required. The results of the study demonstrate the capability of the aptamer sandwich assay platform for diagnosing HCC and its potential applicability to the point-of-care testing (POCT) system.

中文翻译：

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基于适体的夹心测定及其在肝细胞癌（HCC）中检测Lipocalin-2的临床前景。

我们验证了一种基于DNA适配子的单链诊断方法，该方法能够以三明治测定形式检测Lipocalin-2（LCN2），Lipocalin-2（LCN2）是临床相关肝细胞癌（HCC）患者血清中的生物标志物。用SELEX方法筛选了LCN2的9个适体（LCN2_apta1至LCN2_apta9），最后使用表面等离振子共振（SPR）和斑点印迹分析选择了一个三明治对（LCN2_apta2和LCN2_apta4）。提出的适体三明治结构的结果表明，在浓度范围为2.5-500 ng mL（-1）的情况下灵敏地检测到LCN2，检测限为0.6 ng mL（-1）。HCC患者的定量测量测试是在纯血清上进行的，并与常规基于抗体的ELISA试剂盒的性能进行了比较。适体三明治测定法在临床相关的血清水平下显示了LCN2的极佳动态范围，涵盖了每毫升浓度小于毫微纳克的浓度。新方法为检测低丰度和中等丰度的血清生物标志物提供了一种简单而可靠的方法。它由功能化，杂交和信号读出组成，不需要稀释。研究结果证明了适体夹心测定平台诊断HCC的能力及其在即时检验（POCT）系统中的潜在适用性。无需稀释。研究结果证明了适体夹心测定平台诊断HCC的能力及其在即时检验（POCT）系统中的潜在适用性。无需稀释。研究结果证明了适体夹心测定平台诊断HCC的能力及其在即时检验（POCT）系统中的潜在适用性。