Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of c...Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of carcinoembryonic antigen(CEA)coupled with an M-shaped DNA walker(M-DNA walker)as signal switch.Specifically,in comparison with platinum nanoparticles(Pt NPs),Pt HNSs revealed excellent catalytic performance and pore confinement-enhanced ECL,which could significantly amplify ECL intensity of Rub NLs/dissolved O_(2)(DO)binary system.Then,the tracks and M-DNA walker were confined on the Pt HNSs simultaneously to promote the reaction efficiency,whose M-structure boosted the interaction sites between walking strands and tracks and reduced the rigidity of their recognition.Once the CEA approached the sensing interface,the M-DNA walker was activated based on highly specific aptamer recognition to recover ECL intensity with the assistance of exonucleaseⅢ(ExoⅢ).As proof of concept,the“on-off-on”switch aptasensor was constructed for CEA detection with a low detection limit of 0.20 fg/m L.The principle of the constructed ECL aptasensor also enables a universal platform for sensitive detection of other tumor markers.展开更多
Accurate discrimination of cell subtypes at the molecular level is especially important for cancer diagnosis,but no current method allows rapid and precise detection of breast cancer subtypes.Herein,we developed an el...Accurate discrimination of cell subtypes at the molecular level is especially important for cancer diagnosis,but no current method allows rapid and precise detection of breast cancer subtypes.Herein,we developed an elegant DNA walker for direct and rapid differentiation of breast cancer cell subtypes via detection of dual-miRNAs in clinical tissue samples.This DNA nanomachine can be specifically initiated by endogenous miR-21 and miR-31,and the sensitivity was dramatically improved due to the DNAzyme-mediated signal amplification.This DNA walker enabled rapid detection of double miRNA characteristics in different breast cell lines and also distinguished the fluctuations in a single cell.Applications of this DNAzyme-based nanomachine in vivo and in clinical samples were demonstrated for efficient detection of breast cancer subtypes,making the method generally applicable for precise management of cancers.展开更多
MicroRNAs (miRNAs) are vital regulators in both plants and animals. Therefore, it is highly desirable to develop portable and user-friendly biosensors for convenient and sensitive detection of miRNAs. Herein, a novel ...MicroRNAs (miRNAs) are vital regulators in both plants and animals. Therefore, it is highly desirable to develop portable and user-friendly biosensors for convenient and sensitive detection of miRNAs. Herein, a novel paper-based electrochemical biosensor was intelligently engineered for the detection of plant miRNA based on a smart DNA walking machine and λ-exonuclease (λ-Exo)-assisted target recycling amplification. Using TaMIR5086 as a target plant miRNA, the presence of TaMIR5086 could initiate the target recycling process and activate the DNA walker to move along the track on the paper. Then, numerous electroactive molecules-labeled single-strand DNA (ssDNA) would be released and adsorbed onto the surface of screen-printed electrode, generating a remarkably increased electrochemical signal. Benefitting from the dual amplification, the developed biosensor exhibits excellent analytical performance toward TaMIR5086 with a detection limit down to 0.37 pmol/L. Furthermore, the paper-based biosensor could be applied for the analysis of target miRNA in complex biological samples, which found great potential in the fields of miRNA analysis and plant biology research.展开更多
Herein,a dual-signal electrochemical biosensor has been developed by self-assembly of pH-activatable i-motif probes on magnetic microparticles(MMPs)coupled with DNA walker for signal amplification.In this study,the cy...Herein,a dual-signal electrochemical biosensor has been developed by self-assembly of pH-activatable i-motif probes on magnetic microparticles(MMPs)coupled with DNA walker for signal amplification.In this study,the cytosine(C)-rich single-stranded DNAs are hybridized with DNA initiators to obtain the long-nicked duplexes with repeated units,which are further captured on MMPs to form the magnetic i-motif containers.The resulting duplexes contain abundant G-C base pairs,thus providing extensive binding sites for doxorubicin(DOX).At acidic pH,the C-rich sequences are folded into i-motif structure,resulting in the release of DOX and walker initiators.In this case,the liberated DOX is adsorbed on gra-phene quantum dots-modified glassy carbon electrode viaπ-πinteraction,while the walker initiators as a moving part can catalyze the hybridization between MB-modified fueler DNA and tracker DNA on electrode,contributing to the generation of dual electrochemical signals induced by MB and DOX.Importantly,the magnetic separation can effectively reduce the background,achieving sensitive biosensing of pH ranging from 4.0 to 7.4 with excellent stability.Moreover,the proposed dual-signal electrochemical biosensor has been successfully applied for accurate monitoring of pH in human serum,which holds great potential in pH-dependent bioassays,especially in ultra-micro analysis for clinical applications.展开更多
We are all familiar with DNA as the substance that encodes the genomes of all living things.In addition to genetic function,DNA is one of the smartest building blocks for innovative nanostructures.DNA walker is a kind...We are all familiar with DNA as the substance that encodes the genomes of all living things.In addition to genetic function,DNA is one of the smartest building blocks for innovative nanostructures.DNA walker is a kind of self-assembled molecular machine that mimics the movement of protein motors in living systems.Usually,DNA walker consists of three parts:a single stranded DNA track,several anchorage sites and a walker strand.The walker strand can move from展开更多
Strand displacement reaction is a crucial component in the assembly of diverse DNA-based nanodevices,with the toehold-mediated strand displacement reaction representing the prevailing strategy.However,the single-stran...Strand displacement reaction is a crucial component in the assembly of diverse DNA-based nanodevices,with the toehold-mediated strand displacement reaction representing the prevailing strategy.However,the single-stranded Watson-Crick sticky region that serves as the trigger for strand displacement can also cause leakage reactions by introducing crosstalk in complex DNA circuits.Here,we proposed the toeless and reversible DNA strand displacement reaction based on the Hoogsteen-bond triplex,which is compatible with most of the existing DNA circuits.We demonstrated that our proposed reaction can occur at pH 5 and can be reversed at pH 9.We also observed an approximately linear relationship between the degree of reaction and pH within the range of pH 5-6,providing the potential for precise regulation of the reaction.Meanwhile,by altering the sequence orientation,we have demonstrated that our proposed reaction can be initiated or regulated through the same toeless mechanism without the requirement for protonation in low pH conditions.Based on the proposed reaction principle,we further constructed a variety of DNA nanodevices,including two types of DNA logic gates that rely on pH 5/pH 9 changes for initiating and reversing:the AND gate and the OR gate.We also successfully constructed a DNA Walker based on our proposed reaction modes,which can move along a given track after the introduction of a programmable DNA sequence and complete a cycle after 4 steps.Our findings suggest that this innovative approach will have broad utility in the development of DNA circuits,molecular sensors,and other complex biological systems.展开更多
【目的】快速鉴定我国进境植物检疫性害虫南瓜实蝇Bactrocera tau(Walker),防止该虫传入扩散。【方法】基于物种特异性PCR(SS-PCR)技术,选取20种形态近似的常见实蝇,将南瓜实蝇作为阳性对照,提取基因组DNA模板,选用mt DNA COⅠ序列,检...【目的】快速鉴定我国进境植物检疫性害虫南瓜实蝇Bactrocera tau(Walker),防止该虫传入扩散。【方法】基于物种特异性PCR(SS-PCR)技术,选取20种形态近似的常见实蝇,将南瓜实蝇作为阳性对照,提取基因组DNA模板,选用mt DNA COⅠ序列,检查同源系列,设计筛选1对可快速准确鉴定南瓜实蝇的种特异性引物NF404和NR610,并进行PCR检测和验证,建立一种利用种特异性引物的快速鉴定方法。【结果】南瓜实蝇在207 bp的位置扩增出一条清晰且单一的目标条带,其余果实蝇未见条带。将截获的南瓜实蝇与其同亚属的近缘种具条实蝇、瓜实蝇的不同虫态和成虫部分虫体组织的虫样,采用本实验室建立的SS-PCR鉴定方法进行验证,结果一致。【结论】建立的南瓜实蝇的SS-PCR鉴定方法种特异性和稳定性强,能快速鉴定目标种类,解决口岸进境果蔬中截获实蝇幼虫、蛹等不同虫态和残体难于快速鉴定问题。展开更多
The availability and reliability of strategies for molecular biosensing over a finely adjustable dynamic range is essential to enhance the understanding and control of vital biological process. To expand the versatili...The availability and reliability of strategies for molecular biosensing over a finely adjustable dynamic range is essential to enhance the understanding and control of vital biological process. To expand the versatility and utility of nucleic acid- related enzymes, we demonstrated a rational approach to acquiring tunable, pH-dependent deoxyribozymes (DNAzymes) with catalytic activities and response sensitivities that can be tuned through a simple change in solution pH. To do this, we capitalized upon the pH dependence of Hoogsteen interactions and designed i-motif- and triplex-based DNAzymes that can be finely regulated with high precision over a physiologically relevant pH interval. The modified DNAzymes are dependent upon pH for efficient cleavage of substrates, and their catalytic performance can be tuned by regulating the sequence of inserted i-motif/triplex structures. The principle of tunable, pH-dependent DNAzymes provides the opportunity to engineer pH-controlled DNA-machinery devices with unprecedented sensitivity to pH changes. For example, we constructed a DNA-walker device, the stepping rate of which could be adjusted by simply modulating solution pH within an interval of 5.6 to 7.4, as well as a DNA tetrahedron that can be opened at pH 6.4 and kept closed at pH 7.4. The potential of this approach is not limited to serve as pH-dependent devices, but rather may be combined with other elements to expand their practical usefulness.展开更多
基金financially supported by the National Natural Science Foundation(NNSF)of China(No.22022408)the Chongqing Talents Personnel Support Program(No.NCQYC201905067)the Fundamental Research Funds for the Central Universities(No.XDJK2019TJ002)。
文摘Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of carcinoembryonic antigen(CEA)coupled with an M-shaped DNA walker(M-DNA walker)as signal switch.Specifically,in comparison with platinum nanoparticles(Pt NPs),Pt HNSs revealed excellent catalytic performance and pore confinement-enhanced ECL,which could significantly amplify ECL intensity of Rub NLs/dissolved O_(2)(DO)binary system.Then,the tracks and M-DNA walker were confined on the Pt HNSs simultaneously to promote the reaction efficiency,whose M-structure boosted the interaction sites between walking strands and tracks and reduced the rigidity of their recognition.Once the CEA approached the sensing interface,the M-DNA walker was activated based on highly specific aptamer recognition to recover ECL intensity with the assistance of exonucleaseⅢ(ExoⅢ).As proof of concept,the“on-off-on”switch aptasensor was constructed for CEA detection with a low detection limit of 0.20 fg/m L.The principle of the constructed ECL aptasensor also enables a universal platform for sensitive detection of other tumor markers.
基金This work was supported by the National Natural Science Foundation of China(grant no.21974125)the Program for Science and Technology Innovation Teams in Universities of Henan Province(grant no.22IRTSTHN002)+3 种基金the Key Project of Science and Technology of Henan Province(grant no.212102310334)111 Project of Henan Province(grant no.CXJD2021001)the Collaborative Innovation Project of Zhengzhou(grant no.18XTZX12002)Special Funds for the Construction of Innovative Provinces in Hunan Province(grant no.2019RS1031).
文摘Accurate discrimination of cell subtypes at the molecular level is especially important for cancer diagnosis,but no current method allows rapid and precise detection of breast cancer subtypes.Herein,we developed an elegant DNA walker for direct and rapid differentiation of breast cancer cell subtypes via detection of dual-miRNAs in clinical tissue samples.This DNA nanomachine can be specifically initiated by endogenous miR-21 and miR-31,and the sensitivity was dramatically improved due to the DNAzyme-mediated signal amplification.This DNA walker enabled rapid detection of double miRNA characteristics in different breast cell lines and also distinguished the fluctuations in a single cell.Applications of this DNAzyme-based nanomachine in vivo and in clinical samples were demonstrated for efficient detection of breast cancer subtypes,making the method generally applicable for precise management of cancers.
基金financially supported by the National Natural Science Foundation of China(No.22076090)the Shandong Provincial Natural Science Foundation(ZR2020ZD37)the Shandong Province Higher Educational Program for Young Innovation Talents.
文摘MicroRNAs (miRNAs) are vital regulators in both plants and animals. Therefore, it is highly desirable to develop portable and user-friendly biosensors for convenient and sensitive detection of miRNAs. Herein, a novel paper-based electrochemical biosensor was intelligently engineered for the detection of plant miRNA based on a smart DNA walking machine and λ-exonuclease (λ-Exo)-assisted target recycling amplification. Using TaMIR5086 as a target plant miRNA, the presence of TaMIR5086 could initiate the target recycling process and activate the DNA walker to move along the track on the paper. Then, numerous electroactive molecules-labeled single-strand DNA (ssDNA) would be released and adsorbed onto the surface of screen-printed electrode, generating a remarkably increased electrochemical signal. Benefitting from the dual amplification, the developed biosensor exhibits excellent analytical performance toward TaMIR5086 with a detection limit down to 0.37 pmol/L. Furthermore, the paper-based biosensor could be applied for the analysis of target miRNA in complex biological samples, which found great potential in the fields of miRNA analysis and plant biology research.
基金supported by the National Natural Science Foundation of China(22076087)the Special Funds of the Taishan Scholar Program of Shandong Province(tsqn20161028)+2 种基金the Science Foundation for Distinguished Young Scholars of Shandong Province(ZR2020JQ08)the Youth Innovation Technology Program of Shandong Province(2019KJC029)the Collaborative Innovation Program of Jinan(2018GXRC033).
文摘Herein,a dual-signal electrochemical biosensor has been developed by self-assembly of pH-activatable i-motif probes on magnetic microparticles(MMPs)coupled with DNA walker for signal amplification.In this study,the cytosine(C)-rich single-stranded DNAs are hybridized with DNA initiators to obtain the long-nicked duplexes with repeated units,which are further captured on MMPs to form the magnetic i-motif containers.The resulting duplexes contain abundant G-C base pairs,thus providing extensive binding sites for doxorubicin(DOX).At acidic pH,the C-rich sequences are folded into i-motif structure,resulting in the release of DOX and walker initiators.In this case,the liberated DOX is adsorbed on gra-phene quantum dots-modified glassy carbon electrode viaπ-πinteraction,while the walker initiators as a moving part can catalyze the hybridization between MB-modified fueler DNA and tracker DNA on electrode,contributing to the generation of dual electrochemical signals induced by MB and DOX.Importantly,the magnetic separation can effectively reduce the background,achieving sensitive biosensing of pH ranging from 4.0 to 7.4 with excellent stability.Moreover,the proposed dual-signal electrochemical biosensor has been successfully applied for accurate monitoring of pH in human serum,which holds great potential in pH-dependent bioassays,especially in ultra-micro analysis for clinical applications.
文摘We are all familiar with DNA as the substance that encodes the genomes of all living things.In addition to genetic function,DNA is one of the smartest building blocks for innovative nanostructures.DNA walker is a kind of self-assembled molecular machine that mimics the movement of protein motors in living systems.Usually,DNA walker consists of three parts:a single stranded DNA track,several anchorage sites and a walker strand.The walker strand can move from
基金financially supported by the National Key Research and Development Program of China(No.2021YFC2701402)the Open Research Fund of State Key Laboratory of Bioelectronics,Southeast University(No.Sklb2021-k06)+1 种基金the Open Foundation of NHC Key Laboratory of Birth Defect for Research and Prevention(Hunan Provincial Maternal and Child Health Care Hospital)(No.KF2020007)the Open Foundation of Translational Medicine National Science and Technology Infrastructure(Shanghai)(No.TMSK-2021-141)。
文摘Strand displacement reaction is a crucial component in the assembly of diverse DNA-based nanodevices,with the toehold-mediated strand displacement reaction representing the prevailing strategy.However,the single-stranded Watson-Crick sticky region that serves as the trigger for strand displacement can also cause leakage reactions by introducing crosstalk in complex DNA circuits.Here,we proposed the toeless and reversible DNA strand displacement reaction based on the Hoogsteen-bond triplex,which is compatible with most of the existing DNA circuits.We demonstrated that our proposed reaction can occur at pH 5 and can be reversed at pH 9.We also observed an approximately linear relationship between the degree of reaction and pH within the range of pH 5-6,providing the potential for precise regulation of the reaction.Meanwhile,by altering the sequence orientation,we have demonstrated that our proposed reaction can be initiated or regulated through the same toeless mechanism without the requirement for protonation in low pH conditions.Based on the proposed reaction principle,we further constructed a variety of DNA nanodevices,including two types of DNA logic gates that rely on pH 5/pH 9 changes for initiating and reversing:the AND gate and the OR gate.We also successfully constructed a DNA Walker based on our proposed reaction modes,which can move along a given track after the introduction of a programmable DNA sequence and complete a cycle after 4 steps.Our findings suggest that this innovative approach will have broad utility in the development of DNA circuits,molecular sensors,and other complex biological systems.
文摘【目的】快速鉴定我国进境植物检疫性害虫南瓜实蝇Bactrocera tau(Walker),防止该虫传入扩散。【方法】基于物种特异性PCR(SS-PCR)技术,选取20种形态近似的常见实蝇,将南瓜实蝇作为阳性对照,提取基因组DNA模板,选用mt DNA COⅠ序列,检查同源系列,设计筛选1对可快速准确鉴定南瓜实蝇的种特异性引物NF404和NR610,并进行PCR检测和验证,建立一种利用种特异性引物的快速鉴定方法。【结果】南瓜实蝇在207 bp的位置扩增出一条清晰且单一的目标条带,其余果实蝇未见条带。将截获的南瓜实蝇与其同亚属的近缘种具条实蝇、瓜实蝇的不同虫态和成虫部分虫体组织的虫样,采用本实验室建立的SS-PCR鉴定方法进行验证,结果一致。【结论】建立的南瓜实蝇的SS-PCR鉴定方法种特异性和稳定性强,能快速鉴定目标种类,解决口岸进境果蔬中截获实蝇幼虫、蛹等不同虫态和残体难于快速鉴定问题。
基金The authors thank the National Basic Research Pro- gram of China (973 Program) (Nos. 2012CB720600, 2012CB720603, and 2012CB720604), the National Natural Science Foundation of China (Nos. 21432008 and 81373256).
文摘The availability and reliability of strategies for molecular biosensing over a finely adjustable dynamic range is essential to enhance the understanding and control of vital biological process. To expand the versatility and utility of nucleic acid- related enzymes, we demonstrated a rational approach to acquiring tunable, pH-dependent deoxyribozymes (DNAzymes) with catalytic activities and response sensitivities that can be tuned through a simple change in solution pH. To do this, we capitalized upon the pH dependence of Hoogsteen interactions and designed i-motif- and triplex-based DNAzymes that can be finely regulated with high precision over a physiologically relevant pH interval. The modified DNAzymes are dependent upon pH for efficient cleavage of substrates, and their catalytic performance can be tuned by regulating the sequence of inserted i-motif/triplex structures. The principle of tunable, pH-dependent DNAzymes provides the opportunity to engineer pH-controlled DNA-machinery devices with unprecedented sensitivity to pH changes. For example, we constructed a DNA-walker device, the stepping rate of which could be adjusted by simply modulating solution pH within an interval of 5.6 to 7.4, as well as a DNA tetrahedron that can be opened at pH 6.4 and kept closed at pH 7.4. The potential of this approach is not limited to serve as pH-dependent devices, but rather may be combined with other elements to expand their practical usefulness.