title: An aptamer-based immunoassay in microchannels of a portable analyzer for detection of microcystin-leucine-arginine.
abstract: The rapid detection of microcystin-leucine-arginine (MC-LR), the most highly toxic among MCs, is significantly important to environmental and human health protection and prevention of MC-LR from being used as a bioweapon. Although aptamers offer higher affinity, specificity, and stability with MC-LR than antibodies in the immunodetection of MC-LR due to steric hindrance between two antibodies and limited epitopes of MC-LR for use in a sandwich immunoassay, no sandwich immunoassay using an aptmer has been developed for MC-LR detection. This study is aimed at developing an aptamer-antibody immunoassay (AAIA) to detect MC-LR using a portable analyzer. The aptamers were immobilized onto the glass surface of a microchamber to capture MC-LR. MC-LR and horseradish peroxidase (HRP)-labeled antibody were pulled into the microchamber to react with the immobilized aptamer. The chemiluminescence (CL) catalyzed by HRP was tested by a photodiode-based portable analyzer. MC-LR at 0.5-4.0 μg/L was detected quantitatively by the AAIA, with a CL signal sensitivity of 0.3 μg/L. The assay took less than 35 min for a single sample and demonstrated a high specificity, detecting only MC-LR, but not MC-LA, MC-YR, or nodularin-R. The recovery of two spiked real environmental samples calculated as 94.5-112.7%. Therefore, this AAIA was proved to be a rapid and simple method to detect MC-LR in the field by a single analyst.
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, the Fourth Military Medical University, 169 West Changle Road, Xi׳an 710032, People׳s Republic of China.
authors.forename: An
authors.initials: A
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, the Fourth Military Medical University, 169 West Changle Road, Xi׳an 710032, People׳s Republic of China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Lei
authors.affiliation: School of public health, Xi׳an Jiaotong University, Xi׳an 710032, People׳s Republic of China.
authors.forename: Fengling
authors.initials: F
authors.lastname: Ren
authors.affiliation: Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of Life Science and Technology, Xi׳an Jiaotong University, Xi׳an 710032, People׳s Republic of China.
authors.forename: Liuqin
authors.initials: L
authors.lastname: Zang
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, the Fourth Military Medical University, 169 West Changle Road, Xi׳an 710032, People׳s Republic of China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, the Fourth Military Medical University, 169 West Changle Road, Xi׳an 710032, People׳s Republic of China.
authors.forename: Ju
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, the Fourth Military Medical University, 169 West Changle Road, Xi׳an 710032, People׳s Republic of China. Electronic address: luzfliuq@fmmu.edu.cn.
authors.forename: Zifan
authors.initials: Z
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, the Fourth Military Medical University, 169 West Changle Road, Xi׳an 710032, People׳s Republic of China. Electronic address: gyanhai@fmmu.edu.cn.
authors.forename: Yanhai
authors.initials: Y
authors.lastname: Guo
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D001120:Arginine / Q000737:chemistry*; D001427:Bacterial Toxins / Q000032:analysis / Q000276:immunology; D004791:Enzyme Inhibitors / Q000032:analysis / Q000276:immunology; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D007124:Immunoenzyme Techniques; D007930:Leucine / Q000737:chemistry*; D052998:Microcystins / Q000032:analysis* / Q000276:immunology; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000911:Antibodies, Monoclonal; D052157:Aptamers, Nucleotide; D001427:Bacterial Toxins; D004791:Enzyme Inhibitors; D052998:Microcystins; D014874:Water Pollutants, Chemical; C078588:microcystin; D001120:Arginine; D006735:Horseradish Peroxidase; D010749:Phosphoprotein Phosphatases; D007930:Leucine
keywords: Aptamer; Microcystin-leucine-arginine; Portable detection; Sandwich immunoassay