title: Combination of dynamic magnetophoretic separation and stationary magnetic trap for highly sensitive and selective detection of Salmonella typhimurium in complex matrix.
abstract: Foodborne illnesses have always been a serious problem that threats public health, so it is necessary to develop a method that can detect the pathogens rapidly and sensitively. In this study, we designed a magnetic controlled microfluidic device which integrated the dynamic magnetophoretic separation and stationary magnetic trap together for sensitive and selective detection of Salmonella typhimurium (S. typhimurium). Coupled with immunomagnetic nanospheres (IMNs), this device could separate and enrich the target pathogens and realize the sensitive detection of target pathogens on chip. Based on the principle of sandwich immunoassays, the trapped target pathogens identified by streptavidin modified QDs (SA-QDs) were detected under an inverted fluorescence microscopy. A linear range was exhibited at the concentration from 1.0×10(4) to 1.0×10(6) colony-forming units/mL (CFU/mL), the limit of detection (LOD) was as low as 5.4×10(3) CFU/mL in milk (considering the sample volume, the absolute detection limit corresponded to 540C FU). Compared with the device with stationary magnetic trap alone, the integrated device enhanced anti-interference ability and increased detection sensitivity through dynamic magnetophoretic separation, and made the detection in complex samples more accurate. In addition, it had excellent specificity and good reproducibility. The developed system provides a rapid, sensitive and accurate approach to detect pathogens in practice samples.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Pei-Lin
authors.initials: PL
authors.lastname: Guo
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Man
authors.initials: M
authors.lastname: Tang
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Shao-Li
authors.initials: SL
authors.lastname: Hong
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yu
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Dai-Wen
authors.initials: DW
authors.lastname: Pang
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address: zlzhang@whu.edu.cn.
authors.forename: Zhi-Ling
authors.initials: ZL
authors.lastname: Zhang
mesh_terms: D058491:Bacterial Load / Q000295:instrumentation; D015374:Biosensing Techniques / Q000295:instrumentation; D045424:Complex Mixtures / Q000032:analysis; D004586:Electrophoresis / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology / Q000295:instrumentation*; D018189:Immunomagnetic Separation / Q000295:instrumentation*; D015203:Reproducibility of Results; D012486:Salmonella typhimurium / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
chemical_list: D045424:Complex Mixtures
keywords: Combination; Immunomagnetic nanospheres (IMNs); Magnetic trap; Magnetophoretic separation; Salmonella typhimurium (S. typhimurium)