Immobilizing enzyme to nano interfaces has demonstrated to be a favorable strategy for prompting the industrialized application of enzyme.Despite tremendous endeavor has been devoted to using gold nanoparticles(AuNPs)...Immobilizing enzyme to nano interfaces has demonstrated to be a favorable strategy for prompting the industrialized application of enzyme.Despite tremendous endeavor has been devoted to using gold nanoparticles(AuNPs)as conjugation matrix due to its fascinating physico-chemical properties,maintaining enzymatic activity while circumventing cumbersome modification remains a formidable challenge.Herein,the freezing-directed conjugation of enzyme/nano interfaces was constructed without extra reagent.As the proof of concept,glucose oxidase(GOx)was chosen as model enzyme.The one-pot conjugation process can be facilely completed at−20°C under aqueous solution.Moreover,with the loading of GOx on AuNP at freezing,the enzyme exhibited superior catalytic activity and stability upon thermal and pH perturbation.The mechanism of boosted activity was then discussed in detail.It was found that higher loading density under freezing condition and more enzyme tending to bind AuNPs via Au-S bond were the main factors for the superior activity.More importantly,this methodology was universal and can also be applied to other enzyme which contains natural cysteine,such as horseradish peroxidase(HRP)and papain.This facile conjugation strategy accompanied by remarkable bioactivity expand the possibilities for enzymatic biosensing,microdevice and even drug delivery.展开更多
Combining the inhibited aptazyme and molecular beacon （MB）, we developed a versatile sensing strategy for amplified detection of adenosine. In this strategy, the adenosine aptamer links to the 8-17 DNAzyme to form a...Combining the inhibited aptazyme and molecular beacon （MB）, we developed a versatile sensing strategy for amplified detection of adenosine. In this strategy, the adenosine aptamer links to the 8-17 DNAzyme to form an aptazyme. A short sequence, denoted as inhibitor, is designed to form a duplex spanning the aptamer-DNAzyme junction, which blocks the catalytic function of the DNAzyme. Only in the presence of target adenosine, the aptamer binds to adenosine, thus the inhibitor dissociates from the aptamer portion of the aptazyme and can no longer form the stable duplex required to inhibit the catalytic activity of the aptazyme. The released DNAzyme domain will hybridize to the MB and catalyze the cleavage in the presence of Zn2＋, making the fluorophore separate from the quencher and resulting in fluorescence signal. The results showed that the detection method has a dynamic range from 10 nmol/L to 1nmol/L, with a detection limit of 10 nmol/L.展开更多
DNAzyme has emerged as a promising gene silencer for therapeutic applications.However,DNAzymebased gene therapy against tumors is still challenged by undesired cytotoxicity in normal cells.Herein,we explored the poten...DNAzyme has emerged as a promising gene silencer for therapeutic applications.However,DNAzymebased gene therapy against tumors is still challenged by undesired cytotoxicity in normal cells.Herein,we explored the potential application of hybridization chain reaction(HCR)for endogenous miRNA-activated DNAzyme-based gene silencing,which performing amplified signal and cellular onsite therapy in one system.The DNA probes,called HCR-tDz circuits,are designed by combining HCR and therapeutic DNAzyme(tDz).The miRNA-21 is selected as the diagnostic target for its distinctive overexpression in cancerous cells,and the HCR is employed to amplify the miR-21 recognition event as well as the tDz activation.The massively repeated DNAzyme activated by miR-21-triggered HCR is utilized to catalytically cleave early growth response-1 mRNA and implement a cellular gene-silencing strategy.Results show that HCR-tDz nanostructure enables amplified miR-21 imaging in living cells.Furthermore,this nanosystem can effectively inhibit the proliferation of cancer cells with high specificity,thus resulting in sensitive diagnostic signaling and accurate therapeutic effects.展开更多
基金the National Natural Science Foundation of China(Nos.32001782 and 22222402)the Natural Science Foundation of Hunan Province(No.2021JJ40564)+2 种基金Changsha Municipal Natural Science Foundation(No.kq2007021)the Opening Foundation of State Key Laboratory of Chemo/Biosensing and Chemometrics,Hunan University(No.2019013)Open Project of State Key Laboratory of Supramolecular Structure and Materials(No.sklssm2023016).
文摘Immobilizing enzyme to nano interfaces has demonstrated to be a favorable strategy for prompting the industrialized application of enzyme.Despite tremendous endeavor has been devoted to using gold nanoparticles(AuNPs)as conjugation matrix due to its fascinating physico-chemical properties,maintaining enzymatic activity while circumventing cumbersome modification remains a formidable challenge.Herein,the freezing-directed conjugation of enzyme/nano interfaces was constructed without extra reagent.As the proof of concept,glucose oxidase(GOx)was chosen as model enzyme.The one-pot conjugation process can be facilely completed at−20°C under aqueous solution.Moreover,with the loading of GOx on AuNP at freezing,the enzyme exhibited superior catalytic activity and stability upon thermal and pH perturbation.The mechanism of boosted activity was then discussed in detail.It was found that higher loading density under freezing condition and more enzyme tending to bind AuNPs via Au-S bond were the main factors for the superior activity.More importantly,this methodology was universal and can also be applied to other enzyme which contains natural cysteine,such as horseradish peroxidase(HRP)and papain.This facile conjugation strategy accompanied by remarkable bioactivity expand the possibilities for enzymatic biosensing,microdevice and even drug delivery.
基金the financial support of the National Natural Science Foundation of China (Nos.21190044,21205032,and 91027000)National Natural Science Foundation of Postdoctoral Scientists of China (No.2013M531779)+1 种基金Hunan Provincial Natural Science Foundation of China (No.13JJ4032)the Fundamental Research Funds for the Central Universities of China.
文摘Combining the inhibited aptazyme and molecular beacon （MB）, we developed a versatile sensing strategy for amplified detection of adenosine. In this strategy, the adenosine aptamer links to the 8-17 DNAzyme to form an aptazyme. A short sequence, denoted as inhibitor, is designed to form a duplex spanning the aptamer-DNAzyme junction, which blocks the catalytic function of the DNAzyme. Only in the presence of target adenosine, the aptamer binds to adenosine, thus the inhibitor dissociates from the aptamer portion of the aptazyme and can no longer form the stable duplex required to inhibit the catalytic activity of the aptazyme. The released DNAzyme domain will hybridize to the MB and catalyze the cleavage in the presence of Zn2＋, making the fluorophore separate from the quencher and resulting in fluorescence signal. The results showed that the detection method has a dynamic range from 10 nmol/L to 1nmol/L, with a detection limit of 10 nmol/L.
基金This work was supported by the National Natural Science Foundation of China(nos.21735002 and 21874036)the Opening Foundation of the State Key Laboratory of Chemo/Biosensing and Chemometrics,Hunan University(no.2019013)+1 种基金the Changsha Municipal Natural Science Foundation(no.kq2007021)the Natural Science Foundation for Distinguished Young Scholars of Hunan Province(no.2021JJ10011).
文摘DNAzyme has emerged as a promising gene silencer for therapeutic applications.However,DNAzymebased gene therapy against tumors is still challenged by undesired cytotoxicity in normal cells.Herein,we explored the potential application of hybridization chain reaction(HCR)for endogenous miRNA-activated DNAzyme-based gene silencing,which performing amplified signal and cellular onsite therapy in one system.The DNA probes,called HCR-tDz circuits,are designed by combining HCR and therapeutic DNAzyme(tDz).The miRNA-21 is selected as the diagnostic target for its distinctive overexpression in cancerous cells,and the HCR is employed to amplify the miR-21 recognition event as well as the tDz activation.The massively repeated DNAzyme activated by miR-21-triggered HCR is utilized to catalytically cleave early growth response-1 mRNA and implement a cellular gene-silencing strategy.Results show that HCR-tDz nanostructure enables amplified miR-21 imaging in living cells.Furthermore,this nanosystem can effectively inhibit the proliferation of cancer cells with high specificity,thus resulting in sensitive diagnostic signaling and accurate therapeutic effects.
