- 标题
- 摘要
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- 实验方案
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Enzyme-free “on-off-on” photoelectrochemical biosensor based on cascaded quadratic amplification strategy for miRNA 141 detection
摘要： MicroRNAs (miRNAs) assay is of great significance for early diagnosis of diseases, so an enzyme-free “on-off-on” PEC biosensor has been developed for sensitive miRNA 141 determination. Manganese-doped cadmium sulfide coupled with zinc sulfide quantum dots (Mn:CdS@ZnS QDs) and manganese porphyrin (MnPP) have been used as photoelectric material and photosensitizer, respectively. And a high photocurrent of approximately 70.0 μA has been obtained. Cascaded quadratic amplification strategy has been applied in the system. Mn:CdS@ZnS QDs was characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). Photoelectrochemical and electrochemical technologies were used to monitor the fabrication process of the biosensor. The sensing platform exhibits recommendable stability and good selectivity, miRNA 141 can be accurately quantified with a linear range of 1.00 × 10-14 to 1.00 × 10-8 mol·L-1 and the detection limit of 3.30 fmol·L-1. This method provides promising potential to explore sensitive detection models for various biological molecules.
关键词： Hybridization chain reaction,Catalytic hairpin assembly,Manganese-doped cadmium sulfide coupled with zinc sulfide quantum dots,MiRNA 141,Photoelectrochemistry,On-off-on
更新于2025-11-14 17:03:37
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Determination of 17β-estradiol by surface-enhanced Raman spectroscopy merged with hybridization chain reaction amplification on Au@Ag core-shell nanoparticles
摘要： The authors describe an aptamer-based assay for 17β-estradiol. It relies on the combined use of surface enhanced Raman scattering (SERS) and hybridization chain reaction (HCR). The aptamer against 17β-estradiol is applied as the recognition probes, and this results in excellent specificity. Specific recognition of target 17β-estradiol induce the freedom of DNA 2, which will open the stem-loop structure of probe 1 on the Au@Ag and form the partial dsDNA structure. With the nicking enzyme, the partial dsDNA will be hydrolyzed and the reside ssDNA on Au@Ag will form a small stem-loop structure. With the help of the other probe 2 modified Au@Ag and pre-immobilized probe 3 on the well of the microplate, an enzyme-free HCR can occur and tremendous Au@Ag can be assembled along the formed dsDNA in HCR, which can act as the excellent substrate for Raman measurement and greatly amplify the Raman signal of R6G on the Au@Ag. Afterwards, the key factor, ratio between probe 2-Au@Ag (P2) and probe1-Au@Ag (P1), affects the detection sensitivity is systematically optimized for the best sensing performance. The SERS signal of R6G, best measured at 1651 cm?1, increases linearly in the wide range from 1 pM to 10 nM. The detection limit can be as low as 0.1 pM.
关键词： Estrogen,Hybridization chain reaction,SERS,Food safety,Aptamer,Gold nanoparticle,Signal amplification,Environment monitoring
更新于2025-09-23 15:23:52
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Signal-on Electrochemiluminescence Aptasensor for Bisphenol A based on Hybridization Chain Reaction and Electrically Heated Electrode
摘要： A simple and sensitive electrochemiluminescence (ECL) aptasensor has been developed for bisphenol A (BPA) detection. The capture DNA (CDNA) was modified on the heated indium-tin-oxide (ITO) working electrode surface firstly and then hybridized with BPA aptamer to form double strand DNA (dsDNA). The presence of target can cause the releasing of aptamer from the electrode surface since the aptamer prefers to switch its configuration to combine with BPA. Subsequently, the free CDNA will induce hybridization chain reaction (HCR) to produce long dsDNA on the electrode surface. Ru(phen)3 2+ can integrate into the grooves of dsDNA to act as an ECL reagent, thus enhanced ECL signal can be detected. The temperature control during the processes of target recognition and HCR were realized through the heated electrode instead of the bulk solution heating. Furthermore, the performance of the ECL aptasensor can be further enhanced at elevated electrode temperature. Under the optimized conditions, the ECL intensity of the system has a linear relationship with the logarithm of BPA concentration in the range of 2.0 pM-50 nM. The limit of detection (LOD) at 55 °C (electrode surface temperature) was calculated to be 1.5 pM, which was approximately 6.5-fold lower than that at 25 °C. The proposed biosensor has been applied to detect the BPA in drink samples with satisfactory results.
关键词： electrochemiluminescence,hybridization chain reaction,heated indium-tin-oxide electrode,aptamer,bisphenol A
更新于2025-09-23 15:22:29
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Label-free in situ Monitoring of DNA Hybridization Chain Reaction using Sequence-selective Minor-groove Binding Fluorophores
摘要： A novel label-free in situ monitoring system for hybridization chain reaction (HCR) using DNA minor-groove binding fluorophores, Hoechst 33258 (Hoe) or quinone cyanine-dithiazole (QCy-DT), has been developed. Two unmodified hairpin oligodeoxyribonucleotides having incomplete double-stranded AATT sequences enabled target-dependent formation of probe binding sites, i.e., AATT double-strand, in HCR product, and fluorescence enhancement of minor-groove binding fluorophores in situ. Using this system, target DNA can be detected by the fluorescence enhancement of Hoe and QCy-DT in a real-time in situ manner. Further development of a label-free, isothermal detection system might provide a cost-effective and user-friendly method for nucleic acid detection.
关键词： Label-free,Hybridization chain reaction,Minor-groove binding fluorophore,Fluorescence,In situ detection
更新于2025-09-23 15:22:29
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Establishment of a universal and sensitive plasmonic biosensor platform based on the hybridization chain reaction (HCR) amplification induced by a triple-helix molecular switch
摘要： Herein, we established a universal and sensitive plasmonic sensing strategy for biomolecule assays by coupling the hybridization chain reaction (HCR) strategy and a triple-helix molecular switch. Upon the recognition of the target, a single-stranded DNA as a universal trigger (UT) was released from the triple-helix molecular switch (THMS). Thus, the HCR process can be triggered between two hairpins M1 and M2, resulting in the aggregation of gold nanoparticles (AuNPs) via the hybridization between the tail sequence on M1 (or M2) and a DNA–AuNP probe with a dramatic change in the absorbance at 521 nm. More specifically, the strategy, which was conducted by the introduction of target-specific recognition of THMS and universalized by virtue of altering the aptamer or DNA sequence without changing the triple-helix structure, enables simple design for multiple target detection. By taking advantage of THMS, this strategy could enable stable and sensitive detection of a variety of targets including nucleic acids, small molecules and proteins, which may possess great potential for practical applications.
关键词： gold nanoparticles,biomolecule detection,plasmonic biosensor,triple-helix molecular switch,hybridization chain reaction
更新于2025-09-19 17:13:59
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DNA Nanofirecrackers Assembled through Hybridization Chain Reaction for Ultrasensitive SERS Immunoassay of Prostate Specific Antigen
摘要： Isothermal nucleic acid amplification technology has widely adopted for analytical chemistry with the purpose for sensitivity improvement. Herein we present an ultrasensitive concatenated hybridization chain reaction (C-HCR) based surface-enhanced Raman scattering (SERS) immunoassay by forming antibody-antigen-aptamer heterosandwich structures with the model analyte of total prostate specific antigens (tPSA). In the C-HCR, two HCRs, one proceeds with two hairpins, and the other with four biotin-modified hairpins, are coupled, making the formation of DNA nanofirecrackers with the lengths longer than 200 nm and more than four hundred million of binding site of streptavidin modified enzymes. This type of DNA nanofirecrackers through the aptamer encoded linker strand to form heterosandwich structures could provide a general signal application platform such as enzyme catalysis with high amplification efficiency. As a proof of concept, Au@Ag core-shell nanostructures based SERS immunoassay with excellent signal amplification has been developed by employing the streptavidin modified alkaline phosphatase (SA-ALP) through its catalysis of 2-phospho-L-ascorbic acid trisodium salt (AAP) to form Au@Ag core-shell nanostructures via the formation of ascorbic acid (AA) to reduce AgNO3 and deposition of silver element on gold nanorods (AuNRs). The newly developed method has a detection limit as low as 0.94 fg/mL, and has successfully achieved the detection of serum samples from clinical patients, which was consistent with the clinical test results, showing that this C-HCR strategy to form DNA nanofirecrackers has great potential in clinical applications.
关键词： SERS immunoassay,Hybridization Chain Reaction,Prostate Specific Antigen,Ultrasensitive detection,DNA nanofirecrackers
更新于2025-09-19 17:13:59
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Imaging of Receptor Dimers in Zebrafish and Living Cells via Aptamer Recognition and Proximity-induced Hybridization Chain Reaction
摘要： On cell membrane surfaces, receptor protein dimers play a fundamental role in many signaling pathways, which are crucial for normal biological processes and cancer development. Efficient and sensitive analysis of receptor dimers in the native environment is highly desirable. Herein, we present a strategy for amplified imaging of receptor dimers in zebrafish and living cells, which relies on aptamer recognition and proximity-induced hybridization chain reaction. Taking advantages of specific aptamer recognition and enzyme-free signal amplification, this strategy is successfully applied to amplified visualize c-Met receptor dimers in the HGF-independent or -dependent manner. Therefore, the developed imaging strategy paves the way for further investigation of protein dimerization or oligomerization state of cell surface receptors and corresponding activation processes in zebrafish and living cells.
关键词： aptamer recognition,zebrafish,living cells,receptor dimers,hybridization chain reaction
更新于2025-09-10 09:29:36
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DNA-Stabilized Silver Nanoclusters for Label-Free Fluorescence Imaging of Cell Surface Glycans and Fluorescence Guided Photothermal Therapy
摘要： A multifunctional nanoplatform that enables the integration of biological detection, imaging diagnosis, and synergistic therapy into a single nanostructure holds great promise for nanoscience and nanomedicine. Herein, a novel theranostic platform was presented for label-free imaging of cell surface glycans based on DNA/silver nanoclusters (AgNCs) via hybridization chain reaction (HCR) and fluorescence guided photothermal therapy (PTT). In this strategy, a dibenzocyclooctyne (DBCO)-functionalized DNA and two hairpin structures of DNA/AgNCs probes were involved. Following metabolic glycan labeling, the binding of DBCO-functionalized DNA to cell surface initiated HCR, and then cell surface glycans were specifically labeled by DNA/AgNCs fluorescent probes. Furthermore, this signal amplification strategy was adopted in quantitative analysis, and the detection limit could be achieved as low as 20 cells in 200 μL binding buffer. Moreover, the remarkable photothermal properties of DNA/AgNCs via HCR, led to efficient killing of cancer cell and inhibited the tumor growth under imaging guide. In this strategy, DNA/AgNCs were utilized to detect the cellular glycans, which aided in overcoming the high cost and instability of fluorescent dyes. Simultaneously, the HCR process avoided the introduction of excessive azido-sugars under the precondition of ensuring apparent fluorescence. These results indicated that the developed nanoplatform has great potential for specific cell surface glycans imaging and fluorescence guided PTT.
关键词： DNA-stabilized silver nanoclusters,fluorescence guided photothermal therapy,hybridization chain reaction,cell surface glycans,label-free fluorescence imaging
更新于2025-09-09 09:28:46