Immuno-HCR based on contact quenching and fluorescence resonance energy transfer for sensitive and low background detection of Escherichia coli O157:H7.
Escherichia coli O157:H7 makes a major threat to human health. Aiming to detect Escherichia coli O157:H7 sensitively, hybridization chain reaction signal amplified immunoassay (immuno-HCR) based on contact quenching (CQ) and fluorescence resonance energy transfer (FRET) was developed. The background of the new designed HCR hairpins (CQ-FRET hairpins) was reduced by contact-quenching fluorescein (FAM) and breaking FRET from donor (FAM) to acceptor (Cy5). The F/F0 ratio of CQ-FRET hairpins (37.02) was obviously higher than that of two other common HCR fluorescent hairpins (CQ hairpins, 21.45; FRET hairpins, 4.61). The limit of detection of the assay was 3.5 × 101 CFU/mL and obviously lower than that of CQ hairpins based immuno-HCR (3.28 × 103 CFU/mL) and FRET hairpins based immuno-HCR (6.49 × 104 CFU/mL). The proposed low fluorescent background immuno-HCR with high sensitivity which was verified in contaminated milk samples could be potentially used in the detection of various pathogens.
['Duan|Miaolin|M|', 'Xiao|Xiaoyue|X|', 'Huang|Yanmei|Y|', 'Li|Guoqiang|G|', 'Shan|Shan|S|', 'Lv|Xi|X|', 'Zhou|Houde|H|', 'Peng|Silu|S|', 'Liu|Chengwei|C|', 'Liu|Daofeng|D|', 'Lai|Weihua|W|']
D000818:Animals D019453:Escherichia coli O157 D031541:Fluorescence Resonance Energy Transfer D005516:Food Microbiology D007118:Immunoassay D008892:Milk
Contact quenching Fluorescence resonance energy transfer Low background Escherichia coli O157:H7 Hybridization chain reaction