摘要
The sandwich-type lateral fl ow assays relying on dual aptamers with high sensitivity and specifi city have been broadly explored.However,it is unlikely to match a pair of specifi c aptamers that can bind a small molecular target(e.g.,cocaine)simultaneously due to the steric hindrance.In response,we herein introduced the strategy of“one divides into two”into the construction of sandwich-type lateral fl ow strip assay(LFSA).Specifi cally,we split a single cocaine-recognizing aptamer into two segments,either of which was conjugated with gold nanoparticles(AuNPs)or labeled with biotin,serving as signal probe and capture probe,respectively.Upon the presence of the target molecule,a ternary sandwich complex comprised of the two halves of the aptamer and the target formed.Such sandwich-type LFSA exhibited an excellent nonlinear logarithmic response in the range from 10μmol/L to 5 mmol/L with R^(2)=0.9994.The sensitive on-site detection of cocaine in artifi cial biological samples including urine and sweat was achieved within 15 min,with the visual limit of detection as low as 50μmol/L for urine and 200μmol/L for sweat,and the recovery rates of 83.6-107.4%.
基金
supported by the National Natural Science Foundation of China(22090050,22122410,21874121)
the National Key Research and Development Program of China(2018YFE0206900)
Hubei Provincial Natural Science Foundation of China(2020CFA037)
Zhejiang Provincial Natural Science Foundation of China(LD21B050001)
