BACKGROUND Malignant tumors are one of the leading causes of death worldwide,imposing a substantial economic and social burden.Early detection is the key to improving cure rates and reducing mortality rates,which requ...BACKGROUND Malignant tumors are one of the leading causes of death worldwide,imposing a substantial economic and social burden.Early detection is the key to improving cure rates and reducing mortality rates,which requires the development of sensitive early detection technologies.Signal amplification techniques play a crucial role in aptamer-based early detection of tumors and are increasingly garnering attention from researchers.AIM To investigate the current research status,developmental trajectories,and hotspots in signal amplification for aptamer-based tumor detection through bibliometric analysis.METHODS English publications pertaining to signal amplification in aptamer-based tumor detection were retrieved from the Web of Science Core Collection database.VOSviewer and CiteSpace software were employed to analyze various information within this field,including countries,institutions,authors,co-cited authors,journals,co-cited journals,cited references,and keywords.RESULTS A total of 757 publications were included in this study.China accounted for 85.47%of all publications,with Nanjing University(China)emerging as the institution with the highest publication output.The most influential authors and journals were Hasanzadeh M.from Iran and"Biosensors and Bioelectronics",respectively.Exosomes and carcinoembryonic antigen(CEA)stood out as the most researched tumor-related molecules.Currently,the predominant signal amplification technique,nanomaterial,and signal transduction method were identified as hybridization chain reactions,gold nanoparticles,and electrochemical methods,respectively.Over the past 3 years,exosomes,CEA,electrochemical biosensors,and nanosheets have emerged as research hotspots,exhibiting a robust burst of intensity.CONCLUSION This study is the first bibliometric analysis of literature on signal amplification in aptamer-based tumor detection and elucidates the current status,hotspots,and prospective research directions within this realm.Additionally,it provides an important reference for researchers.展开更多
Liquid biopsy is a technology that exhibits potential to detect cancer early,monitor therapies,and predict cancer prognosis due to its unique characteristics,including noninvasive sampling and real-time analysis.Circu...Liquid biopsy is a technology that exhibits potential to detect cancer early,monitor therapies,and predict cancer prognosis due to its unique characteristics,including noninvasive sampling and real-time analysis.Circulating tumor cells(CTCs)and extracellular vesicles(EVs)are two important components of circulating targets,carrying substantial disease-related molecular information and playing a key role in liquid biopsy.Aptamers are single-stranded oligonucleotides with superior affinity and specificity,and they can bind to targets by folding into unique tertiary structures.Aptamer-based microfluidic platforms offer new ways to enhance the purity and capture efficiency of CTCs and EVs by combining the advantages of microfluidic chips as isolation platforms and aptamers as recognition tools.In this review,we first briefly introduce some new strategies for aptamer discovery based on traditional and aptamer-based microfluidic approaches.Then,we subsequently summarize the progress of aptamer-based microfluidics for CTC and EV detection.Finally,we offer an outlook on the future directional challenges of aptamer-based microfluidics for circulating targets in clinical applications.展开更多
Background:Raloxifene,a selective estrogen receptor modulator,is also known to be a lysosomotropic agent.The bioavailability of raloxifene is around 2%due to extensive hepatic transport.Exosomes are nanosized vesicles...Background:Raloxifene,a selective estrogen receptor modulator,is also known to be a lysosomotropic agent.The bioavailability of raloxifene is around 2%due to extensive hepatic transport.Exosomes are nanosized vesicles that are naturally released from cells.Method:In this study,exosomes released from HeLa cervical cancer cells were loaded with raloxifene to increase its bioavailability,and an aptamer was attached to the exosome membrane for targeting only HeLa cells.Characterization of exosomes isolated from HeLa cells was performed by transmission electron microscopy,zeta sizer,and western blotting.In addition,the cytotoxic,apoptotic,autophagic,and lysosomotropic effects of the prepared Exo-Apt-Ral formulation on HeLa cervical cancer cells were investigated.Results:According to zeta analysis,the sizes of the empty exosome and Exo-Apt-Ral formulation were measured as 66±12 and 120±21 nm,respectively.There was a rise in the lysosomal permeability of HeLa cells after the Exo-Apt-Ral application.In addition,both apoptotic and autophagic death mechanisms were triggered in HeLa cells after the Exo-Apt-Ral application.Conclusion:This study showed that raloxifene functionalized by loading into aptamer-bound exosomes can be a new targeted drug carrier system for cervical cancer.展开更多
Staphylococcus aureus is a gram-staining positive cocci bacillus baterium and also one of the foodborne pathogens, which is a serious potential hazard to human health and food safety. We constructed an electroche...Staphylococcus aureus is a gram-staining positive cocci bacillus baterium and also one of the foodborne pathogens, which is a serious potential hazard to human health and food safety. We constructed an electrochemical biosensor for the detection of S. aureus based on nucleic acid aptamers to achieve highly specific detection of S. aureus. The detection of S. aureus was realized by using Aptamer (Apt) to capture S. aureus, which resulted in a change in the spatial conformation of Apt and a decrease in the electrochemical signal. Under the optimized experimental conditions, the detected electrochemical signals were positively correlated with the concentration of S. aureus with a linear range of 1 × 10<sup>1</sup> - 1 × 10<sup>5</sup> CFU/mL, a detection limit of 4.76 CFU/mL, and an experimental recovery of 97.43% - 99.37%. Therefore, we successfully constructed an electrochemical biosensor for the specific detection of S. aureus, which has the advantages of high specificity, sensitive detection and convenient operation.展开更多
Aptamers as a kind of biological recognition element have shown great potential in monitoring and the rapid quantification of organophosphorus pesticides(OPPs). However, molecules of OPPs are structurally similar and ...Aptamers as a kind of biological recognition element have shown great potential in monitoring and the rapid quantification of organophosphorus pesticides(OPPs). However, molecules of OPPs are structurally similar and original aptamers selected by systematic evolution of ligands by exponential enrichment are usually long-chain bases, which hamper the further application under OPPs-aptamer recognition. The aim of the research was to develop a new strategy to design oligonucleotide sequences for binding OPPs by combination of experimental and molecular modeling methods. 3D models of aptamers binding OPPs were constructed, and binding energy and the most probable binding site for the OPPs were then determined by molecular docking, and the binding sites were further confirmed by the results of 2-AP replaced experiments. Based on the docking results, a new aptamer for detection 4 representative OPPs with only 29 bases was designed by reasonable truncation and mutation of the reported aptamer(named S4-29). The interaction between this new aptamer and OPPs were analyzed by molecular docking, microscale thermophoresis, circular dichroism and fluorometric analysis. The results revealed that the new aptamer exhibit more superior recognition performance to OPPs, which can be promote the monitoring ability of OPPs contaminations in food.展开更多
Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target m...Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target molecules with high affinity and specificity represent an attractive tool for the recognition of food hazardous substances,which play an important role in the development and application of new food safety detection technology.But current assays for characterizing small molecule-aptamer binding are limited by either the mass sensitivity or the size differentiation ability.Herein,we proposed a comprehensive method for assessing the dissociation equilibria of small molecule-aptamer,which is immobilized-free under ambient conditions.The design employs the Le Chatelier’s principle and could be used to effectively measure small molecule-aptamer interactions.ATP binding aptamer and anti-aflatoxin B1 aptamer were used as the model system to determine their affinity,in which their dissociation equilibria measurements are in excellent close to their previous work.Due to the simplicity and sensitivity of this new method,we believe that it could be recommended as an effective tool for characterizing small molecule-aptamer interactions and promote the further application of small molecular aptamer in food safety.展开更多
Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.Th...Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.The selected aptamers are capable of specifically binding to different targeting molecules,which is achieved by the three-dimensional structure of aptamers.Aptamers are similar in function to monoclonal antibodies,and therefore,they are also referred to as"chemical antibodies".Due to their high affinity and specificity and low immunogenicity,aptamers are topics of intense interest in today's biological targeting research especially in tumor research.They not only have high potential for clinical advances in tumor targeting detection but also are highly promising as targeted tumor drug carriers for use in tumor therapy.Various experimental studies have shown that aptamer-based diagnostic and therapeutic methods for liver cancer have great potential for application.This paper summarizes the structure,characteristics,and screening methods of aptamers and reviews the recent research progress on nucleic acid aptamers in the targeted diagnosis and treatment of liver cancer.展开更多
Aptamer-silver nanoparticles (AgNPs) based surface-enhanced Raman scattering (SERS) sensor has been developed for Hg^2+ detection by employing the structure-switching aptamer in the presence of spermine. This sim...Aptamer-silver nanoparticles (AgNPs) based surface-enhanced Raman scattering (SERS) sensor has been developed for Hg^2+ detection by employing the structure-switching aptamer in the presence of spermine. This simple method shows excellent sensitivity and selectivity owing to the sensitive SERS detection technique and high specificity of aptamer for binding Hg^2+.展开更多
A robust, selective and highly sensitive chemiluminescent (CL) platform for protein assay was presented in this paper. This novel CL approach utilized rolling circle amplification (RCA) as a signal enhancement tec...A robust, selective and highly sensitive chemiluminescent (CL) platform for protein assay was presented in this paper. This novel CL approach utilized rolling circle amplification (RCA) as a signal enhancement technique and the 96-well plate as the immobilization and separation carrier. Typically, the antibody immobilized on the surface of 96-well plate was sandwiched with the protein target and the aptamer-primer sequence. This aptamer-primer sequence was then employed as the primer of RCA. Based on this design, a number of the biotinylated probes and streptavidin-horseradish peroxidase (SA-HRP) were captured on the plate, and the CL signal was amplified. In summary, our results demonstrated a robust biosensor with a detection limit of 10 fM that is easy to be established and utilized, and devoid of light source. Therefore, this new technique .will broaden the perspective for future development of DNA-based biosensors for the detection of other protein biomarkers related to clinical diseases, by taking advantages of high sensitivity and selectivity.展开更多
A new adenosine biosensor based on aptamer probe is introduced in this article. An amino-labeled aptamer probe was immobilized on the gold electrode modified with an o-phenylenediamine electropolymerized film. When ad...A new adenosine biosensor based on aptamer probe is introduced in this article. An amino-labeled aptamer probe was immobilized on the gold electrode modified with an o-phenylenediamine electropolymerized film. When adenosine is bound specifically to the aptamer probe, the interface of the biosensor is changed, resulting in the decrement of the peak current. The response current is proportional to the amount of adenosine in sample. The used electrode can be easily regenerated in hot water. The proposed biosensor represents a linear response to adenosine over a concentration range of 1.0x 10^-7-l.0x10^-4 mol/L with a detection limit of 1.0xl0^-8 mol/L. The presented biosensor exhibits a nice specificity towards adenosine. It offers a promising approach for adenosine assay due to its excellent electrochemical properties that are believed to be very attractive for electrochemical studies and electroanalytical applications.展开更多
Objective:To select the specific aptamer of carcinoembryonic antigen (CEA), one of the most attractive molecule for cancer target therapy and imaging. Methods: Seven rounds in vitro selection were performed agains...Objective:To select the specific aptamer of carcinoembryonic antigen (CEA), one of the most attractive molecule for cancer target therapy and imaging. Methods: Seven rounds in vitro selection were performed against the purified CEA protein. Ligand-mediated target purification and Co-immunoprecipitation were adopted to verify the specific binding of the aptamer to the purified and native protein separately. Results:The CEA-specific aptamer which can bind both the purified and native protein with the high specificity was obtained. Conclusion:This is the first time the CEA specific apatmer was produced. The results in this study provides the preliminary evidence for further investigation and application of CEA-aptamer in the future.展开更多
Aptamers are specific nucleic acid sequences that can bind to a wide range of nucleic acid and non-nucleic acid targets with high affinity and specificity. Nucleic acid aptamers are selected in vitro from single stran...Aptamers are specific nucleic acid sequences that can bind to a wide range of nucleic acid and non-nucleic acid targets with high affinity and specificity. Nucleic acid aptamers are selected in vitro from single stranded DNA or RNA ligands containing random sequences of up to a few hundred nucleotides. Systematic evolution of ligands by exponential enrichment (SELEX) was used to select and PCR amplify DNA sequences (aptamers) capable of binding to and detecting Listeria monocytogenes, one of the major food-borne pathogens. A simplified affinity separation approach was employed, in which L. monocytogenes in exponential (log) phase of growth was used as the separation target. A fluorescently-labeled aptamer assay scheme was devised for detecting L. monoeytogenes. This report described a novel approach to the detection of L. monocytogenes using DNA aptamers. Aptamers were developed by nine rounds of SELEX. A high affinity aptamer was successfully selected from the initial random DNA pool, and its secondary structure was also investigated. One of aptamers named e01 with the highest affinity was further tested in aptamer-peroxidase and aptamer-fluorescence staining protocols. This study has proved the principle that the whole-cell SELEX could be a promising technique to design aptamer-based molecular probes for dectection of pathogenic microorganisms without tedious isolation and purification of complex markers or targets.展开更多
基金National Natural Science Foundation of China,No.82160494 and No.82160444.
文摘BACKGROUND Malignant tumors are one of the leading causes of death worldwide,imposing a substantial economic and social burden.Early detection is the key to improving cure rates and reducing mortality rates,which requires the development of sensitive early detection technologies.Signal amplification techniques play a crucial role in aptamer-based early detection of tumors and are increasingly garnering attention from researchers.AIM To investigate the current research status,developmental trajectories,and hotspots in signal amplification for aptamer-based tumor detection through bibliometric analysis.METHODS English publications pertaining to signal amplification in aptamer-based tumor detection were retrieved from the Web of Science Core Collection database.VOSviewer and CiteSpace software were employed to analyze various information within this field,including countries,institutions,authors,co-cited authors,journals,co-cited journals,cited references,and keywords.RESULTS A total of 757 publications were included in this study.China accounted for 85.47%of all publications,with Nanjing University(China)emerging as the institution with the highest publication output.The most influential authors and journals were Hasanzadeh M.from Iran and"Biosensors and Bioelectronics",respectively.Exosomes and carcinoembryonic antigen(CEA)stood out as the most researched tumor-related molecules.Currently,the predominant signal amplification technique,nanomaterial,and signal transduction method were identified as hybridization chain reactions,gold nanoparticles,and electrochemical methods,respectively.Over the past 3 years,exosomes,CEA,electrochemical biosensors,and nanosheets have emerged as research hotspots,exhibiting a robust burst of intensity.CONCLUSION This study is the first bibliometric analysis of literature on signal amplification in aptamer-based tumor detection and elucidates the current status,hotspots,and prospective research directions within this realm.Additionally,it provides an important reference for researchers.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.:82003710 and 82173808)the Natural Science Foundation of Guangdong Province(Grant Nos.:2020A1515010075 and 2021B1515020100)+3 种基金the Project of Educational Commission of Guangdong Province(Grant No.:2021ZDZX2012)the Guangzhou Basic and Applied Basic Research Project(Grant No.:2023A04J1163)the National Key Clinical Specialty Construction Project(Clinical Pharmacy)High-Level Clinical Key Specialty(Clinical Pharmacy)in Guangdong Province,China.
文摘Liquid biopsy is a technology that exhibits potential to detect cancer early,monitor therapies,and predict cancer prognosis due to its unique characteristics,including noninvasive sampling and real-time analysis.Circulating tumor cells(CTCs)and extracellular vesicles(EVs)are two important components of circulating targets,carrying substantial disease-related molecular information and playing a key role in liquid biopsy.Aptamers are single-stranded oligonucleotides with superior affinity and specificity,and they can bind to targets by folding into unique tertiary structures.Aptamer-based microfluidic platforms offer new ways to enhance the purity and capture efficiency of CTCs and EVs by combining the advantages of microfluidic chips as isolation platforms and aptamers as recognition tools.In this review,we first briefly introduce some new strategies for aptamer discovery based on traditional and aptamer-based microfluidic approaches.Then,we subsequently summarize the progress of aptamer-based microfluidics for CTC and EV detection.Finally,we offer an outlook on the future directional challenges of aptamer-based microfluidics for circulating targets in clinical applications.
基金supported by a Grant(221S945)from the Scientific and Technological Research Council of Turkey(TUBITAK)an Aydin Adnan Menderes University Research Grant(ADU-TPF-20041).
文摘Background:Raloxifene,a selective estrogen receptor modulator,is also known to be a lysosomotropic agent.The bioavailability of raloxifene is around 2%due to extensive hepatic transport.Exosomes are nanosized vesicles that are naturally released from cells.Method:In this study,exosomes released from HeLa cervical cancer cells were loaded with raloxifene to increase its bioavailability,and an aptamer was attached to the exosome membrane for targeting only HeLa cells.Characterization of exosomes isolated from HeLa cells was performed by transmission electron microscopy,zeta sizer,and western blotting.In addition,the cytotoxic,apoptotic,autophagic,and lysosomotropic effects of the prepared Exo-Apt-Ral formulation on HeLa cervical cancer cells were investigated.Results:According to zeta analysis,the sizes of the empty exosome and Exo-Apt-Ral formulation were measured as 66±12 and 120±21 nm,respectively.There was a rise in the lysosomal permeability of HeLa cells after the Exo-Apt-Ral application.In addition,both apoptotic and autophagic death mechanisms were triggered in HeLa cells after the Exo-Apt-Ral application.Conclusion:This study showed that raloxifene functionalized by loading into aptamer-bound exosomes can be a new targeted drug carrier system for cervical cancer.
文摘Staphylococcus aureus is a gram-staining positive cocci bacillus baterium and also one of the foodborne pathogens, which is a serious potential hazard to human health and food safety. We constructed an electrochemical biosensor for the detection of S. aureus based on nucleic acid aptamers to achieve highly specific detection of S. aureus. The detection of S. aureus was realized by using Aptamer (Apt) to capture S. aureus, which resulted in a change in the spatial conformation of Apt and a decrease in the electrochemical signal. Under the optimized experimental conditions, the detected electrochemical signals were positively correlated with the concentration of S. aureus with a linear range of 1 × 10<sup>1</sup> - 1 × 10<sup>5</sup> CFU/mL, a detection limit of 4.76 CFU/mL, and an experimental recovery of 97.43% - 99.37%. Therefore, we successfully constructed an electrochemical biosensor for the specific detection of S. aureus, which has the advantages of high specificity, sensitive detection and convenient operation.
基金supported by the National Natural Science Foundation of China (31801647)Sichuan Science and Technology Program (2018JY0194,2020YFN0153,2020YFN0151)。
文摘Aptamers as a kind of biological recognition element have shown great potential in monitoring and the rapid quantification of organophosphorus pesticides(OPPs). However, molecules of OPPs are structurally similar and original aptamers selected by systematic evolution of ligands by exponential enrichment are usually long-chain bases, which hamper the further application under OPPs-aptamer recognition. The aim of the research was to develop a new strategy to design oligonucleotide sequences for binding OPPs by combination of experimental and molecular modeling methods. 3D models of aptamers binding OPPs were constructed, and binding energy and the most probable binding site for the OPPs were then determined by molecular docking, and the binding sites were further confirmed by the results of 2-AP replaced experiments. Based on the docking results, a new aptamer for detection 4 representative OPPs with only 29 bases was designed by reasonable truncation and mutation of the reported aptamer(named S4-29). The interaction between this new aptamer and OPPs were analyzed by molecular docking, microscale thermophoresis, circular dichroism and fluorometric analysis. The results revealed that the new aptamer exhibit more superior recognition performance to OPPs, which can be promote the monitoring ability of OPPs contaminations in food.
基金supported by the National Key R&D Program of China(2017YFC1600603)the Funds for Huangshan Professorship of Hefei University of Technology(407-037019).
文摘Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target molecules with high affinity and specificity represent an attractive tool for the recognition of food hazardous substances,which play an important role in the development and application of new food safety detection technology.But current assays for characterizing small molecule-aptamer binding are limited by either the mass sensitivity or the size differentiation ability.Herein,we proposed a comprehensive method for assessing the dissociation equilibria of small molecule-aptamer,which is immobilized-free under ambient conditions.The design employs the Le Chatelier’s principle and could be used to effectively measure small molecule-aptamer interactions.ATP binding aptamer and anti-aflatoxin B1 aptamer were used as the model system to determine their affinity,in which their dissociation equilibria measurements are in excellent close to their previous work.Due to the simplicity and sensitivity of this new method,we believe that it could be recommended as an effective tool for characterizing small molecule-aptamer interactions and promote the further application of small molecular aptamer in food safety.
文摘Aptamers are a class of single oligonucleotide molecules(DNA or RNA)that are screened from random DNA or RNA oligonucleotide chain libraries by the systemic evolution of ligands by exponential enrichment technology.The selected aptamers are capable of specifically binding to different targeting molecules,which is achieved by the three-dimensional structure of aptamers.Aptamers are similar in function to monoclonal antibodies,and therefore,they are also referred to as"chemical antibodies".Due to their high affinity and specificity and low immunogenicity,aptamers are topics of intense interest in today's biological targeting research especially in tumor research.They not only have high potential for clinical advances in tumor targeting detection but also are highly promising as targeted tumor drug carriers for use in tumor therapy.Various experimental studies have shown that aptamer-based diagnostic and therapeutic methods for liver cancer have great potential for application.This paper summarizes the structure,characteristics,and screening methods of aptamers and reviews the recent research progress on nucleic acid aptamers in the targeted diagnosis and treatment of liver cancer.
基金supported by the One Hundred Person Project of the Chinese Academy of Sciencesthe Department of Science and Technology of Shandong Province(No.2008GG20005005).
文摘Aptamer-silver nanoparticles (AgNPs) based surface-enhanced Raman scattering (SERS) sensor has been developed for Hg^2+ detection by employing the structure-switching aptamer in the presence of spermine. This simple method shows excellent sensitivity and selectivity owing to the sensitive SERS detection technique and high specificity of aptamer for binding Hg^2+.
基金financial support from the National Drug Innovative Program (2009ZX09301-011)the Research Fund for the Doctoral Program of Higher Education (200802461096,20090071110056)
文摘A robust, selective and highly sensitive chemiluminescent (CL) platform for protein assay was presented in this paper. This novel CL approach utilized rolling circle amplification (RCA) as a signal enhancement technique and the 96-well plate as the immobilization and separation carrier. Typically, the antibody immobilized on the surface of 96-well plate was sandwiched with the protein target and the aptamer-primer sequence. This aptamer-primer sequence was then employed as the primer of RCA. Based on this design, a number of the biotinylated probes and streptavidin-horseradish peroxidase (SA-HRP) were captured on the plate, and the CL signal was amplified. In summary, our results demonstrated a robust biosensor with a detection limit of 10 fM that is easy to be established and utilized, and devoid of light source. Therefore, this new technique .will broaden the perspective for future development of DNA-based biosensors for the detection of other protein biomarkers related to clinical diseases, by taking advantages of high sensitivity and selectivity.
基金Supported by the National Natural Science Foundation of China(Nos20675028, 20435010 and 20375012)the Science Commission of Hunan Province, China
文摘A new adenosine biosensor based on aptamer probe is introduced in this article. An amino-labeled aptamer probe was immobilized on the gold electrode modified with an o-phenylenediamine electropolymerized film. When adenosine is bound specifically to the aptamer probe, the interface of the biosensor is changed, resulting in the decrement of the peak current. The response current is proportional to the amount of adenosine in sample. The used electrode can be easily regenerated in hot water. The proposed biosensor represents a linear response to adenosine over a concentration range of 1.0x 10^-7-l.0x10^-4 mol/L with a detection limit of 1.0xl0^-8 mol/L. The presented biosensor exhibits a nice specificity towards adenosine. It offers a promising approach for adenosine assay due to its excellent electrochemical properties that are believed to be very attractive for electrochemical studies and electroanalytical applications.
基金This work was supported by the China National Natural Science Foundation(30670958).
文摘Objective:To select the specific aptamer of carcinoembryonic antigen (CEA), one of the most attractive molecule for cancer target therapy and imaging. Methods: Seven rounds in vitro selection were performed against the purified CEA protein. Ligand-mediated target purification and Co-immunoprecipitation were adopted to verify the specific binding of the aptamer to the purified and native protein separately. Results:The CEA-specific aptamer which can bind both the purified and native protein with the high specificity was obtained. Conclusion:This is the first time the CEA specific apatmer was produced. The results in this study provides the preliminary evidence for further investigation and application of CEA-aptamer in the future.
文摘Aptamers are specific nucleic acid sequences that can bind to a wide range of nucleic acid and non-nucleic acid targets with high affinity and specificity. Nucleic acid aptamers are selected in vitro from single stranded DNA or RNA ligands containing random sequences of up to a few hundred nucleotides. Systematic evolution of ligands by exponential enrichment (SELEX) was used to select and PCR amplify DNA sequences (aptamers) capable of binding to and detecting Listeria monocytogenes, one of the major food-borne pathogens. A simplified affinity separation approach was employed, in which L. monocytogenes in exponential (log) phase of growth was used as the separation target. A fluorescently-labeled aptamer assay scheme was devised for detecting L. monoeytogenes. This report described a novel approach to the detection of L. monocytogenes using DNA aptamers. Aptamers were developed by nine rounds of SELEX. A high affinity aptamer was successfully selected from the initial random DNA pool, and its secondary structure was also investigated. One of aptamers named e01 with the highest affinity was further tested in aptamer-peroxidase and aptamer-fluorescence staining protocols. This study has proved the principle that the whole-cell SELEX could be a promising technique to design aptamer-based molecular probes for dectection of pathogenic microorganisms without tedious isolation and purification of complex markers or targets.