Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, 59 Cangwu Road, Haizhou, 222005, Lianyungang, China.
State Key Laboratory of Genetic Engineering, MOE Engineering Research Centre of Gene Technology, School of Life Sciences, Fudan University, Shanghai, 200438, China.
Mikrochim Acta. 2024 Jul 23;191(8):479. doi: 10.1007/s00604-024-06555-2.
Sialyl-Lewis (SLe) is a tetrasugar, which plays an important role in initial inflammation and cancer cell metastasis, and can be used as a marker for cancer diagnosis and prognosis or a therapeutic target. Detecting SLe from complex biological media remains a significant challenge. Herein, a single-stranded DNA aptamer of SLe was screened based on the double-stranded DNA library-modified magnetic bead (MB)-SELEX technology. After 14 rounds of screening, 12,639 sequences were obtained and divided into nine families. Three representative sequences were selected based on the number of sequence repeats and Gibbs binding free energy, and the aptamer SLe-Apt2 with 80 nt length (K = 23.01 nM) had the best affinity and relatively high specificity for targeting SLe. Then, a novel dual-recognition fluorescent biosensor for SLe-sensitive detection based on aptamer SLe-Apt2 bio-dots and 3-aminobenzoboric acid-modified MB was developed. This method can detect SLe as low as 32 μM and has a good linear response in the range 100 μM to 2 mM. It has the advantages of low preparation cost, good targeting, and avoiding the occurrence of false-positive and false-negative detection results, which makes the biosensor more valuable in biological detection and clinical diagnosis.
唾液酸化路易斯（SLe）是一种四糖，在初始炎症和癌细胞转移中起重要作用，可作为癌症诊断和预后的标志物或治疗靶点。从复杂的生物介质中检测 SLe 仍然是一个重大挑战。在此，基于双链 DNA 文库修饰的磁性珠（MB）-SELEX 技术筛选了 SLe 的单链 DNA 适体。经过 14 轮筛选，获得了 12639 个序列，并分为九个家族。根据序列重复数和 Gibbs 结合自由能选择了三个代表性序列，其中长度为 80nt 的适体 SLe-Apt2（Kd = 23.01 nM）具有最佳亲和力和相对较高的特异性，可靶向 SLe。然后，基于适体 SLe-Apt2 生物点和 3-氨基苯硼酸修饰的 MB ，开发了一种用于 SLe 敏感检测的新型双重识别荧光生物传感器。该方法可检测低至 32μM 的 SLe，在 100μM 至 2mM 的范围内具有良好的线性响应。它具有制备成本低、靶向性好、避免假阳性和假阴性检测结果的优点，使生物传感器在生物检测和临床诊断中更具价值。
