title: CdTe/CdSe quantum dot-based fluorescent aptasensor with hemin/G-quadruplex DNzyme for sensitive detection of lysozyme using rolling circle amplification and strand hybridization.
abstract: Lysozyme with a small monomeric globular enzymatic protein is part of the innate immune system, and its deficiency can cause the increased incidence of disease. Herein, we devise a new signal-enhanced fluorescence aptasensing platform for quantitative screening of lysozyme by coupling with rolling circle amplification (RCA) and strand hybridization reaction, accompanying the assembly of CdTe/CdSe quantum dots (QDs) and hemin/G-quadruplex DNzyme. Initially, target-triggered release of the primer was carried out from DNA duplex via the reaction of the aptamer with the analyte, and the released primer could be then utilized as the template to produce numerous repeated oligonucleotide sequences by the RCA reaction. Following that, the formed long-stranded DNA simultaneously hybridized with the CdTe/CdSe QD-labeled probe and hemin/G-quadruplex DNzyme strand in the system, thereby resulting in the quenching of QD fluorescent signal through the proximity hemin/G-quadruplex DNzyme on the basis of transferring photoexcited conduction band electrons of quantum dots to Fe(III)/Fe(II)-protoporphyrin IX (hemin) complex. Under optimal conditions, the fluorescent signal decreased with the increasing target lysozyme within the dynamic range from 5.0 to 500nM with a detection limit (LOD) of 2.6nM at the 3sblankcriterion. Intra-assay and interassay coefficients of variation (CVs) were below 8.5% and 11.5%, respectively. Finally, the system was applied to analyze spiked human serum samples, and the recoveries in all cases were 85-111.9%.
authors: Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou, 350108 People's Republic of China.
authors: Zhenli
authors: Z
authors: Qiu
authors: Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou, 350108 People's Republic of China.
authors: Jian
authors: J
authors: Shu
authors: Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou, 350108 People's Republic of China. Electronic address: heyu@fzu.edu.cn.
authors: Yu
authors: Y
authors: He
authors: Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou, 350108 People's Republic of China.
authors: Zhenzhen
authors: Z
authors: Lin
authors: Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou, 350108 People's Republic of China.
authors: Kangyao
authors: K
authors: Zhang
authors: Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou, 350108 People's Republic of China.
authors: Shuzhen
authors: S
authors: Lv
authors: Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou, 350108 People's Republic of China. Electronic address: dianping.tang@fzu.edu.cn.
authors: Dianping
authors: D
authors: Tang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry*; D021881:DNA, Catalytic / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D009113:Muramidase / Q000032:analysis / Q000097:blood*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D018036:Selenium Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013691:Tellurium / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D019187:Cadmium Compounds; D021881:DNA, Catalytic; D005456:Fluorescent Dyes; D018036:Selenium Compounds; D006427:Hemin; C058667:cadmium selenide; D009113:Muramidase; D013691:Tellurium; C028337:cadmium telluride
keywords: CdTe/CdSe quantum dots; Fluorescent aptasensor; Hemin/G-quadruplex DNzyme; Lysozyme; Rolling circle amplification