title: An easy and sensitive sandwich assay for detection of Mycobacterium tuberculosis Ag85B antigen using quantum dots and gold nanorods.
abstract: Mycobacterium tuberculosis is a serious global infectious pathogen causing tuberculosis (TB). The development of an easy and sensitive method for the detection of M. tuberculosis is in urgent need due to complex and low specificity of the current assays. Herein, we present a novel method for M. tuberculosis detection based on a sandwich assay via antigen-antibody interaction using silica-coated quantum dots (SiQDs) and gold nanorods (AuNRs). A genetically engineered recombinant antibody (GBP-50B14 and SiBP-8B3) was bound to surfaces of AuNRs and SiQDs respectively, without any surface modification. The antigen-antibody interaction was revealed using M. tuberculosis-specific secretory antigen, Ag85B. Two biocomplexes showed a quenching effect in the presence of the target antigen through a sandwich assay. The assay response was in the range of 1×10-3-1×10-10μgmL-1(R=0.969) and the limit of detection for Ag85B was 13.0pgmL-1. The Ag85B was selectively detected using three different proteins (CFP10, and BSA), and further specifically confirmed by the use of spiked samples. Compared with existing methods, a highly sensitive and selective method for Ag85B-expressing M. tuberculosis detection has been developed for better diagnosis of TB.
authors.affiliation: Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
authors.forename: Eun Bee
authors.initials: EB
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
authors.forename: Seung Woo
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
authors.forename: Seon Ah
authors.initials: SA
authors.lastname: Cheon
authors.affiliation: Department of Microbiology and Research Institute for Medical Science, College of Medicine, Chungnam National University, Daejeon 301-747, Republic of Korea.
authors.forename: Hwa-Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Departments of Nano Fusion and Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Jaebeom
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Chung-Ang University Hospital, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Department of Biotechnology, CHA University, CHA Bio Complex, 335 Pangyo-ro, Bundang-gu, Seongnam, Gyeonggi-do 463-836, Republic of Korea. Electronic address: shko7@cha.ac.kr.
authors.forename: Sungho
authors.initials: S
authors.lastname: Ko
authors.affiliation: Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea. Electronic address: tjpark@cau.ac.kr.
authors.forename: Tae Jung
authors.initials: TJ
authors.lastname: Park
mesh_terms: D000217:Acyltransferases / Q000032:analysis / Q000652:urine*; D000942:Antigens, Bacterial / Q000032:analysis / Q000652:urine*; D001426:Bacterial Proteins / Q000032:analysis / Q000652:urine*; D019187:Cadmium Compounds / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D018796:Immunoconjugates / Q000737:chemistry; D057230:Limit of Detection; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D020349:Surface Plasmon Resonance / Q000379:methods*; D013691:Tellurium / Q000737:chemistry; D014376:Tuberculosis / Q000382:microbiology / Q000652:urine*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D019187:Cadmium Compounds; D018796:Immunoconjugates; D006046:Gold; D000217:Acyltransferases; C121433:antigen 85B, Mycobacterium tuberculosis; D013691:Tellurium; C028337:cadmium telluride
keywords: Ag85B; Biosensor; Gold nanorods; Mycobacterium tuberculosis; Quantum dots