科研之友
微信
新浪微博
Facebook
分享链接
摘要
A simple, fast and convenient colorimetric aptasensor was fabricated for the detection of Salmonella typhimurium (S. typhimurium) which was based on the color change effect of gold nanoparticles (GNPs). S. typhimurium is one of the most common causes of food-associated disease. Aptamers with specific recognition toward S. typhimurium was modified to the surface of prepared GNPs. They play a role for the protection of GNPs from aggregation toward high concentrations of NaCI. With the addition of S. typhimurium, aptamers preferably combined to S. typhimurium and the protection effect was broken. With more S. typhimurium, more aptamers detached from GNPs. In such a situation, the exposed GNPs would aggregated to some extent with the addition of NaCI. The color changed from red, purple to blue which could be characterized by UV-Vis spectrophotometer. The absorbance spectra of GNPs redshifted constantly and the intensity ratio of A700/A521 changed regularly. This could be calculated for the basis of quantitative detection of S. typhimurium from 102 cfu/mL to 107 cfu/mL. The obtained linear correlation equation was y = 0.1946x-0.2800 (R-2 = 0.9939) with a detection limit as low as 56 cfu/mL. This method is simple and rapid, results in high sensitivity and specificity, and can be used to detect actual samples.
- 出版日期2017-3-20
- 单位食品科学与技术国家重点实验室; 江南大学; 江苏建康职业学院
