Ultrasensitive microfluidic immunosensor with stir bar enrichment for point-of-care test of Staphylococcus aureus in foods triggered by DNAzyme-assisted click reaction
2022; Elsevier BV; Volume: 378; Linguagem: Inglês
10.1016/j.foodchem.2022.132093
ISSN1873-7072
AutoresJiaqi Wang, Lei Tan, Wenchao Bi, Hao-Yu Shen, Dengfeng Li, Zhenzhong Yu, Ning Gan,
Tópico(s)Advanced Biosensing Techniques and Applications
ResumoThis work demonstrated an ultrasensitive and simple microfluidic immunosensor for point-of-care test of Staphylococcus aureus (S. aureus) based on the stir bar enrichment and DNAzyme-assisted click reaction. Initially, S. aureus was enriched by the 4-mercaptophenylboronic acid-functionalized stir bar. The yolk antibody (immunoglobulin Y) and copper-labeled polydopamine nanoparticles were then specifically conjugated with the captured target. The Cu(II) was released under acidic conditions and effectively catalyzed the copper-catalyzed azide-alkyne cycloaddition (CuAAC) between the alkyne group-labeled DNAzyme and the streptavidin-biotin-azido with the assistance of DNAzyme. Finally, the DNAzyme-streptavidin complexes were detected by microfluidic chips to quantify S. aureus. Under optimum conditions, this immunosensor showed good detection performances toward S. aureus within 10 to 2.5 × 104 CFU/mL with a limit of detection of 3 CFU/mL. Moreover, the satisfying detection results of real samples of animal origin also implied that this immunosensor owned great potential in practical applications.
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