title: Chemiluminescent labels released from long spacer arm-functionalized magnetic particles: a novel strategy for ultrasensitive and highly selective detection of pathogen infections.
abstract: Previously, the unique advantages provided by chemiluminescence (CL) and magnetic particles (MPs) have resulted in the development of many useful nucleic acid detection methods. CL is highly sensitive, but when applied to MPs, its intensity is limited by the inner filter-like effect arising from excess dark MPs. Herein, we describe a modified strategy whereby CL labels are released from MPs to eliminate this negative effect. This approach relies on (1) the magnetic capture of target molecules on long spacer arm-functionalized magnetic particles (LSA-MPs), (2) the conjugation of streptavidin-alkaline phosphatase (SA-AP) to biotinylated amplicons of target pathogens, (3) the release of CL labels (specifically, AP tags), and (4) the detection of the released labels. CL labels were released from LSA-MPs through LSA ultrasonication or DNA enzymolysis, which proved to be the superior method. In contrast to conventional MPs, LSA-MPs exhibited significantly improved CL detection, because of the introduction of LSA, which was made of water-soluble carboxymethylated β-1,3-glucan. Detection of hepatitis B virus with this technique revealed a low detection limit of 50 fM, high selectivity, and excellent reproducibility. Thus, this approach may hold great potential for early stage clinical diagnosis of infectious diseases.
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Haowen
authors.initials: H
authors.lastname: Yang
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Liang
authors.forename: Nongyue
authors.initials: N
authors.lastname: He
authors.forename: Yan
authors.initials: Y
authors.lastname: Deng
authors.forename: Zhiyang
authors.initials: Z
authors.lastname: Li
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D019921:Biotinylation; D004247:DNA / Q000737:chemistry; D003851:Deoxyribonucleases / Q000737:chemistry; D006509:Hepatitis B / Q000175:diagnosis; D006515:Hepatitis B virus / Q000302:isolation & purification*; D006801:Humans; D057230:Limit of Detection; D049449:Luminescence; D008163:Luminescent Measurements / Q000295:instrumentation; D008280:Magnetics; D009693:Nucleic Acid Hybridization; D009696:Nucleic Acids / Q000737:chemistry; D010316:Particle Size; D015203:Reproducibility of Results; D012995:Solubility; D019809:Streptavidin / Q000737:chemistry; D014465:Ultrasonics; D014867:Water / Q000737:chemistry; D047071:beta-Glucans / Q000737:chemistry
chemical_list: D009696:Nucleic Acids; D047071:beta-Glucans; D014867:Water; D004247:DNA; D019809:Streptavidin; C033363:beta-1,3-glucan; D003851:Deoxyribonucleases; D000469:Alkaline Phosphatase
keywords: chemiluminescent label; infectious pathogen; long spacer arm; magnetic particle; ultrasensitive detection