title: Quantum dot layer-by-layer assemblies as signal amplification labels for ultrasensitive electronic detection of uropathogens.
abstract: The preparation and use of a new class of signal amplification label, quantum dot (QD) layer-by-layer (LBL) assembled polystyrene microsphere composite, for amplified ultrasensitive electronic detection of uropathogen-specific DNA sequences is described. The target DNA is sandwiched between the capture probes immobilized on the magnetic beads and the signaling probes conjugated to the QD LBL assembled polystyrene beads. Because of the dramatic signal amplification by the numerous QDs involved in each single DNA binding event, subfemtomolar level detection of uropathogen-specific DNA sequences is achieved, which makes our strategy among the most sensitive electronic approach for nucleic acid-based monitoring of pathogens. Our signal amplified detection scheme could be readily expanded to monitor other important biomolecules (e.g., proteins, peptides, amino acids, cells, etc.) in ultralow levels and thus holds great potential for early diagnosis of disease biomarkers.
authors.affiliation: Key Laboratory of Ministry of Education on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. yunatswu@swu.edu.cn
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiang
authors.forename: Haixia
authors.initials: H
authors.lastname: Zhang
authors.forename: Bingying
authors.initials: B
authors.lastname: Jiang
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D004269:DNA, Bacterial / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D008280:Magnetics; D009693:Nucleic Acid Hybridization; D011137:Polystyrenes / Q000737:chemistry; D045663:Quantum Dots; D056689:Uropathogenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D011137:Polystyrenes