Department of Chemistry, Alfaisal University, 11533, Riyadh, Kingdom of Saudi Arabia.
School of Biochemistry and Biotechnology, University of the Punjab, Lahore, Pakistan.
Sci Rep. 2024 Jun 19;14(1):14132. doi: 10.1038/s41598-024-65075-4.
This study introduces an innovative electrochemical aptasensor designed for the highly sensitive and rapid detection of Legionella pneumophila serogroup 1 (L. pneumophila SG1), a particularly virulent strain associated with Legionellosis. Employing a rigorous selection process utilizing cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX), we identified new high-affinity aptamers specifically tailored for L. pneumophila SG1. The selection process encompassed ten rounds of cell-SELEX cycles with live L. pneumophila, including multiple counter-selection steps against the closely related Legionella sub-species. The dissociation constant (K) of the highest affinity sequence to L. pneumophila SG1 was measured at 14.2 nM, representing a ten-fold increase in affinity in comparison with the previously reported aptamers. For the development of electrochemical aptasensor, a gold electrode was modified with the selected aptamer through the formation of self-assembled monolayers (SAMs). The newly developed aptasensor exhibited exceptional sensitivity, and specificity in detecting and differentiating various Legionella sp., with a detection limit of 5 colony forming units (CFU)/mL and an insignificant/negligible cross-reactivity with closely related sub-species. Furthermore, the aptasensor effectively detected L. pneumophila SG1 in spiked water samples, demonstrating an appreciable recovery percentage. This study shows the potential of our aptamer-based electrochemical biosensor as a promising approach for detecting L. pneumophila SG1 in diverse environments.
本研究介绍了一种创新的电化学适体传感器，用于高度敏感和快速检测嗜肺军团菌血清群 1（L. pneumophila SG1），这是一种与军团菌病相关的特别毒力菌株。我们采用基于细胞的配体指数富集系统进化（cell-SELEX）进行严格的筛选过程，鉴定出专门针对 L. pneumophila SG1 的新型高亲和力适体。筛选过程包括十轮带有活的 L. pneumophila 的 cell-SELEX 循环，包括针对密切相关的军团菌亚种的多次反选择步骤。与之前报道的适体相比，对 L. pneumophila SG1 亲和力最高的序列的解离常数（K）为 14.2 nM，亲和力提高了十倍。为了开发电化学适体传感器，通过自组装单分子层（SAM）将所选适体修饰到金电极上。新开发的适体传感器在检测和区分各种军团菌方面表现出出色的灵敏度和特异性，检测限为 5 个菌落形成单位（CFU）/mL，与密切相关的亚种几乎没有交叉反应。此外，该适体传感器能够有效检测水样中的 L. pneumophila SG1，回收率相当可观。本研究表明，基于适体的电化学生物传感器作为一种在不同环境中检测 L. pneumophila SG1 的有前途的方法具有潜力。
