School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bang Khun Thian Chai Thale Road, Bang Khun Thian, Bangkok 10150, Thailand.
Biosens Bioelectron. 2011 Apr 15;26(8):3584-9. doi: 10.1016/j.bios.2011.02.005. Epub 2011 Feb 16.
Among the methods used to detect pathogenic bacteria, enzyme linked immunosorbent assay (ELISA) is one of the most widely used techniques in routine sample analysis. For Salmonella enterica serovar Typhimurium detection, a typical ELISA yields a sensitivity of 10(6)-10(7)CFU/ml. To enhance the detection sensitivity, single-walled carbon nanotubes (SWCNTs) was employed in this study as a labelling platform for antibody and horseradish peroxidase (HRP) co-immobilizing. With high proteins recovery after the coupling process, the resulting Ab/SWCNTs/HRP bioconjugate was used in the proof-of-concept ELISA experiments. Limit of detection (LOD) was found to be 10(3) and 10(4)CFU/ml for direct and sandwich ELISA, respectively, when Ab/HRP at 1:400 ratio was used. This figure accounts for 1000-time greater in detection sensitivity when compared to a commercial Ab-HRP conjugate. The Ab/SWCNTs/HRP bioconjugate was tested further in real samples and found a superior activity over the commercial Ab-HRP by showing 100-time greater detection limit.
在用于检测病原菌的方法中，酶联免疫吸附测定（ELISA）是常规样本分析中应用最广泛的技术之一。对于肠炎沙门氏菌血清型鼠伤寒的检测，典型的 ELISA 的灵敏度为 10(6)-10(7)CFU/ml。为了提高检测灵敏度，本研究采用单壁碳纳米管（SWCNTs）作为抗体和辣根过氧化物酶（HRP）共固定的标记平台。在偶联过程后，具有高蛋白质回收率，所得的 Ab/SWCNTs/HRP 生物缀合物用于概念验证 ELISA 实验。当使用 1:400 比例的 Ab/HRP 时，直接和夹心 ELISA 的检测限（LOD）分别为 10(3)和 10(4)CFU/ml。与商业 Ab-HRP 缀合物相比，这一数字在检测灵敏度方面提高了 1000 倍。进一步在实际样品中测试了 Ab/SWCNTs/HRP 生物缀合物，发现其检测限比商业 Ab-HRP 高 100 倍，具有更好的活性。
