The Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, Bangkok, 10330, Thailand.
Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand; Center of Excellence for Food and Water Risk Analysis (FAWRA), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
Biosens Bioelectron. 2023 Dec 15;242:115742. doi: 10.1016/j.bios.2023.115742. Epub 2023 Oct 5.
An electrochemical lateral flow immunoassay (eLFIA) strip with high reproducibility was developed to rapidly and accurately detect Streptococcus suis serotype 2. This proposed strip was fabricated by integrating ratiometric electrochemical detection and LFIA (R-eLFIA). The R-eLFIA exhibited excellent reproducibility, which was improved by 3.8 times compared to a single electrode. A dual-working screen-printed graphene electrode (SPGE) was designed by tuning the working electrode with electroactive species in the biosensing system. Ferrocene carboxylic acid (Fc) was used as a signal probe, and sunset yellow (SY) at one working electrode was used as an internal reference signal to provide a built-in correction for reducing the effects of inherent background current. S. suis serotype 2-specific antibodies were immobilized on a nitrocellulose membrane of LFIA, which is located on the position of Fc-SPGE. In the presence of the analyte, an immunocomplex formed on the region of Fc-SPGE, causing a decrease in Fc current while SY current remained constant. The current ratio's decrease was proportional to S. suis serotype 2's concentration. Under optimization, this biosensor showed good linearity in the range of 10-10 CFU/mL with a limit of detection of 10 CFU/mL and achieved a rapid detection time (15 min). Moreover, the R-eLFIA biosensor exhibited excellent reproducibility and high selectivity and was applied in human serum samples. Thus, this study successfully matched the advantages of the ratiometric strategy and LFIA and has great potential to be used as an effective tool for rapidly detecting S. suis serotype 2 in clinical samples.
一种具有高重现性的电化学侧向流动免疫分析 (eLFIA) 条带被开发出来，用于快速准确地检测猪链球菌 2 型。该条带通过整合比率电化学检测和 LFIA（R-eLFIA）来制造。与单个电极相比，R-eLFIA 表现出出色的重现性，提高了 3.8 倍。通过在生物传感系统中调整工作电极上的电活性物质来设计双工作丝网印刷石墨烯电极 (SPGE)。使用二茂铁羧酸 (Fc) 作为信号探针，并用日落黄 (SY) 在一个工作电极上作为内部参考信号，提供内置校正以减少固有背景电流的影响。猪链球菌 2 型特异性抗体被固定在 LFIA 的硝酸纤维素膜上，该膜位于 Fc-SPGE 的位置上。在存在分析物的情况下，免疫复合物在 Fc-SPGE 区域形成，导致 Fc 电流减少，而 SY 电流保持不变。电流比的降低与猪链球菌 2 型的浓度成正比。在优化条件下，该生物传感器在 10-10 CFU/mL 的范围内表现出良好的线性关系，检测限为 10 CFU/mL，检测时间快速（15 分钟）。此外，R-eLFIA 生物传感器表现出出色的重现性和高选择性，并应用于人血清样品。因此，本研究成功地结合了比率策略和 LFIA 的优势，具有很大的潜力成为快速检测临床样本中猪链球菌 2 型的有效工具。
