基于适配体识别-杂交链式反应可视化检测金黄色葡萄球菌

该研究以金黄色葡萄球菌核酸适配体为识别分子,结合杂交链式反应和酶催化双重信号放大策略,建立了一种金黄色葡萄球菌高灵敏可视化检测方法.结果显示,在适配体包被浓度60 nmol/L、检测探针浓度80 nmol/L、发夹DNA浓度80 nmol/L、10 g/L牛血清白蛋白封闭4 h、链霉亲和素-辣根过氧化物酶稀释体积比1:...

Colorimetric detection of Staphylococcus aureus using aptamers and hybridization chain reaction amplification

A ultrasensitive colorimetric assay was developed for the detection of Staphylococcus aureus based on hybridization chain reaction with enzyme-amplification using aptamer as the recognition probe. The results showed that the optimal conditions for this method were as follows: aptamer 60 nmol/L, detection probe 80 nmol/L, hairpin DNA 80 nmol/L, bovine serum albumin concentration 10 g/L, blocking time 4 h, dilution volume ratio of streptavidin-horseradish peroxidase(SA-HRP) 1:40 000, incubation time between S. aureus and aptamers 30 min, hybridization time of hairpin DNA 60 min. Under the optimal conditions, the calibration curves for S. aureus showed good linearities in the range of 10-10⁵CFU/mL with correlation coefficients(R) of 0.992. The limit of detection was 10 CFU/mL, and there was no cross-reaction with other food-borne pathogens. Subsequently, the proposed method was applied to measure S. aureus in real samples, and was validated using official standard method. There was no significant difference between the detection results of the two methods(P > 0.05). The recoveries of S. aureus in food samples were in the range of 91.8%-98.2%, and the relative standard deviation was less than 6%. This developed method has the advantages of simple pretreatment, high sensitivity, low detection cost and good accuracy, and is suitable for rapid determination of S. aureus in batch samples.