The Experts below are selected from a list of 840 Experts worldwide ranked by ideXlab platform
Kui Jiao - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical impedimetric DNA sensing based on multi-walled carbon nanotubes-SnO2-chitosan nanocomposite.
Colloids and surfaces. B Biointerfaces, 2013Co-Authors: Tao Yang, Xiuhong Guo, Ling Zhong, Kui JiaoAbstract:Abstract A sensitive electrochemical impedimetric DNA biosensor based on the integration of tin oxide (SnO2) nanoparticles, chitosan (CHIT) and multi-walled carbon nanotubes (MWNTs) is presented in this paper. The MWNTs–SnO2–CHIT composite modified gold electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with individual MWNTs–CHIT, SnO2–CHIT and bare gold electrode, this composite showed the most obvious electrochemical signal of the redox probe [Fe(CN)6]3−/4−. According to the change of the electron transfer resistance (Ret) induced by the hybridization, target DNA was successfully detected via EIS. This DNA electrochemical biosensor was applied to detect Phosphinothricin Acetyltransferase (PAT) gene in transgenic corn. The synergistic effect of the MWNTs–SnO2–CHIT remarkably enhanced DNA immobilization and hybridization detection. The dynamic detection range was from 1.0 × 10−11 mol/L to 1.0 × 10−6 mol/L with a detection limit of 2.5 × 10−12 mol/L. This sensing platform showed inner advantage, such as simplicity, good stability, and high sensitivity.
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Improved electrochemical performances of polyaniline nanotubes-poly-L-lysine composite for label-free impedance detection of DNA hybridization
Science China Chemistry, 2010Co-Authors: Tao Yang, Wei Zhang, Chen Jiang, Kui JiaoAbstract:A sensitive label-free DNA hybridization biosensing platform was fabricated based on the synergistic effect of polyaniline nanotubes (PANInt) and poly-L-lysine (pLys). The composite of pLys and PANInt was coated onto the carbon paste electrode (CPE) to form a uniform and very stable nanocomposite membrane. The pLys in the composite film not only acts as a membrane to retain good electron transfer capability of PANInt even at physiological pH, but also possesses fine biocompatibility for bio-analytes. DNA probes with negatively charged phosphate groups were readily linked to the positively charged pLys surface due to the strong electrostatic affinity. The synergistic effect of PANInt and pLys could significantly enhance the sensitivity of DNA hybridization recognition. The Phosphinothricin Acetyltransferase (PAT) gene fragment from transgenic corn and the polymerase chain reaction amplification of the terminator of nopaline synthase gene from the real sample of a kind of transgenic soybean were detected by this DNA electrochemical biosensor via label-free impedance method. This stable composite gives convenient permselectivity properties as a transducer material for the design of modern electrochemical impedance biosensor using [Fe(CN)6]3−/4− as an indicator.
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electrochemical deoxyribonucleic acid biosensor based on multiwalled carbon nanotubes ag tio2 composite film for label free Phosphinothricin Acetyltransferase gene detection by electrochemical impedance spectroscopy
Chinese Journal of Analytical Chemistry, 2010Co-Authors: Na Zhou, Tao Yang, Kui Jiao, Cai-xia SongAbstract:Abstract A highly sensitive electrochemical deoxyribonucleic acid (DNA) biosensor based on multiwalled carbon nanotubes (MWNT)/Ag-TiO2 composite film was developed. The solution containing Ag-TiO2-MWNT composite was cast on the carbon paste electrode surface to form a robust film, which combined the advantages of the good biocompatibility of Ag-TiO2 composite and the fine conductivity, as well as the large active surface area of carbon nanotubes. The composite could greatly improve the immobilization capacity of the probe DNA. The morphologies and electrochemistry of the nanocomposite film were investigated by scanning electron microscopy and electrochemical techniques including electrochemical impedance spectroscopy and cyclic voltammetry, respectively. DNA hybridization events were monitored by a label-free method of electrochemical impedance spectroscopy. This label-free electrochemical impedance DNA biosensor showed high sensitivity and selectivity for Phosphinothricin Acetyltransferase gene sequence assay. The multicomponents films also displayed a high stability during repeated regeneration and hybridization process.
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Electrochemical Deoxyribonucleic Acid Biosensor Based on Multiwalled Carbon Nanotubes/Ag-TiO2 Composite Film for Label-Free Phosphinothricin Acetyltransferase Gene Detection by Electrochemical Impedance Spectroscopy
Chinese Journal of Analytical Chemistry, 2010Co-Authors: Na Zhou, Tao Yang, Kui Jiao, Cai-xia SongAbstract:Abstract A highly sensitive electrochemical deoxyribonucleic acid (DNA) biosensor based on multiwalled carbon nanotubes (MWNT)/Ag-TiO2 composite film was developed. The solution containing Ag-TiO2-MWNT composite was cast on the carbon paste electrode surface to form a robust film, which combined the advantages of the good biocompatibility of Ag-TiO2 composite and the fine conductivity, as well as the large active surface area of carbon nanotubes. The composite could greatly improve the immobilization capacity of the probe DNA. The morphologies and electrochemistry of the nanocomposite film were investigated by scanning electron microscopy and electrochemical techniques including electrochemical impedance spectroscopy and cyclic voltammetry, respectively. DNA hybridization events were monitored by a label-free method of electrochemical impedance spectroscopy. This label-free electrochemical impedance DNA biosensor showed high sensitivity and selectivity for Phosphinothricin Acetyltransferase gene sequence assay. The multicomponents films also displayed a high stability during repeated regeneration and hybridization process.
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Electrochemical characterization of deoxyribonucleic acid on aluminum(III)/poly(l-glutamic acid) film and its application for the detection of Phosphinothricin Acetyltransferase gene-specific sequence
Thin Solid Films, 2009Co-Authors: Na Zhou, Tao Yang, Chen Jiang, Yongchun Zhang, Kui JiaoAbstract:Abstract A simple strategy of transgenic sequence-specific detection without a special amplification procedure was developed on the basis of aluminum(III)/poly( l -glutamic acid) (PLGA) film. An aluminum ion (Al(III)) thin film was assembled on the surface of PLGA via the electrostatic binding of Al(III) with carboxyl, namely Al(III)/PLGA. The immobilization of deoxyribonucleic acid (DNA) was carried out on this Al(III)/PLGA film by Al(III)-single strand DNA (ssDNA) interaction. Surface hybridization between the immobilized ssDNA and its complementary ssDNA was monitored by electrochemical impedance spectroscopy (EIS) using [Fe(CN) 6 ] 3−/4− as a redox probe. Under the optimal conditions, this DNA electrochemical sensor was applied to determine the specific gene sequence related to Phosphinothricin Acetyltransferase transgene (PAT) in the transgenic plants by label-free EIS.
Moon-sik Yang - One of the best experts on this subject based on the ideXlab platform.
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Expression of a cholera toxin B subunit in transgenic lettuce (Lactuca sativa L.) using Agrobacterium-mediated transformation system
Plant Cell Tissue and Organ Culture, 2006Co-Authors: Young-sook Kim, Bang-geul Kim, Tae-geum Kim, Tae-jin Kang, Moon-sik YangAbstract:To increase expression level of cholera toxin B subunit (CTB) in lettuce plants, synthetic CTB (sCTB) gene based on the optimized codon usage was fused with an endoplasmic reticulum retention signal, KDEL. The sCTB gene was introduced into a plant expression vector and transformed to lettuce plants using Agrobacterium -mediated transformation system. As a selection marker, a bialaphos resistance ( bar ) gene that encodes Phosphinothricin Acetyltransferase (PAT), conferring tolerance to the herbicide Phosphinothricin (PPT), was used. PCR amplification of genomic DNA confirmed the presence of the sCTB gene in the transgenic lettuce plants. Expressions of mRNA and protein of sCTB were observed by Northern and Western blot analyses, respectively. The sCTB synthesized in the transgenic lettuce showed strong affinity for GM_1-ganglioside suggesting that the sCTB conserved the antigenic sites for binding and proper folding of pentameric CTB structure. The expression level of CTB was relatively high, reaching total soluble protein (TSP) levels of 0.24% in transgenic lettuce.
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Expression of a cholera toxin B subunit in transgenic lettuce (Lactuca sativa L.) using Agrobacterium-mediated transformation system
Plant Cell Tissue and Organ Culture, 2006Co-Authors: Young-sook Kim, Bang-geul Kim, Tae-geum Kim, Tae-jin Kang, Moon-sik YangAbstract:To increase expression level of cholera toxin B subunit (CTB) in lettuce plants, synthetic CTB (sCTB) gene based on the optimized codon usage was fused with an endoplasmic reticulum retention signal, KDEL. The sCTB gene was introduced into a plant expression vector and transformed to lettuce plants using Agrobacterium-mediated transformation system. As a selection marker, a bialaphos resistance (bar) gene that encodes Phosphinothricin Acetyltransferase (PAT), conferring tolerance to the herbicide Phosphinothricin (PPT), was used. PCR amplification of genomic DNA confirmed the presence of the sCTB gene in the transgenic lettuce plants. Expressions of mRNA and protein of sCTB were observed by Northern and Western blot analyses, respectively. The sCTB synthesized in the transgenic lettuce showed strong affinity for GM1-ganglioside suggesting that the sCTB conserved the antigenic sites for binding and proper folding of pentameric CTB structure. The expression level of CTB was relatively high, reaching total soluble protein (TSP) levels of 0.24% in transgenic lettuce.
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Expression of the B subunit of E. coli heat-labile enterotoxin in tobacco using a herbicide resistance gene as a selection marker
Plant Cell Tissue and Organ Culture, 2005Co-Authors: Tae-jin Kang, So-chon Han, Moon-sik YangAbstract:The B subunit of Escherichia coli heat-labile enterotoxin (LTB) has been transformed to plants for use as an edible vaccine. We have developed a simple and reliable Agrobacterium-mediated transformation method to express synthetic LTB gene in N. tabacum using a Phosphinothricin Acetyltransferase (bar) gene as a selectable marker. The synthetic LTB gene adapted to the coding sequence of tobacco plants was cloned to a plant expression vector under the control of the ubiquitin promoter and transformed to tobacco by Agrobacterium-mediated transformation. Transgenic plants were selected in the medium supplemented with 5 mg l-1 Phosphinothricin (PPT). The amount of LTB protein detected in the transgenic tobacco was approximately 3.3% of the total soluble protein, approximately 300-fold higher than in the plants generated using the native LTB gene under the control of the CaMV 35S promoter. The transgenic plants that were transferred to a greenhouse had harvested seeds that proved to be resistant to herbicide. Thus, the described protocol could provide a useful tool for the transformation of tobacco plants.
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Herbicide resistance of tobacco chloroplasts expressing the bar gene.
Molecules and cells, 2003Co-Authors: Tae-jin Kang, Jo-eun Seo, Nguyen Hoang Loc, Moon-sik YangAbstract:The chloroplast transformation system has the potential advantages of maternal inheritance and high-level expression of heterologous genes. We studied the expression of the bar gene in tobacco chloroplasts to test these ideas. The bar gene conferring tolerance to the herbicide Phosphinothricin (PPT) encodes Phosphinothricin Acetyltransferase (PAT). It was introduced into the chloroplast genome at a targeted site by homologous recombination. Transplastomic plantlets were selected in medium supplemented with PPT (up to 50 mg l(-1)). The polymerase chain reaction (PCR) and Southern blot analysis confirmed that bar had been inserted at the specified site in the chloroplast genome. The transplastomic plants transferred to a greenhouse proved to be resistant to 2% PPT. Reciprocal crosses between wild type and transplastomic plants confirmed maternal inheritance of the PPT resistance and high levels of PAT activity in the transplastomic plants were confirmed by assays of PAT and of ammonium evolution. The technology demonstrated here could perhaps be usefully transferred to other crop species.
Tao Yang - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical impedimetric DNA sensing based on multi-walled carbon nanotubes-SnO2-chitosan nanocomposite.
Colloids and surfaces. B Biointerfaces, 2013Co-Authors: Tao Yang, Xiuhong Guo, Ling Zhong, Kui JiaoAbstract:Abstract A sensitive electrochemical impedimetric DNA biosensor based on the integration of tin oxide (SnO2) nanoparticles, chitosan (CHIT) and multi-walled carbon nanotubes (MWNTs) is presented in this paper. The MWNTs–SnO2–CHIT composite modified gold electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with individual MWNTs–CHIT, SnO2–CHIT and bare gold electrode, this composite showed the most obvious electrochemical signal of the redox probe [Fe(CN)6]3−/4−. According to the change of the electron transfer resistance (Ret) induced by the hybridization, target DNA was successfully detected via EIS. This DNA electrochemical biosensor was applied to detect Phosphinothricin Acetyltransferase (PAT) gene in transgenic corn. The synergistic effect of the MWNTs–SnO2–CHIT remarkably enhanced DNA immobilization and hybridization detection. The dynamic detection range was from 1.0 × 10−11 mol/L to 1.0 × 10−6 mol/L with a detection limit of 2.5 × 10−12 mol/L. This sensing platform showed inner advantage, such as simplicity, good stability, and high sensitivity.
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Improved electrochemical performances of polyaniline nanotubes-poly-L-lysine composite for label-free impedance detection of DNA hybridization
Science China Chemistry, 2010Co-Authors: Tao Yang, Wei Zhang, Chen Jiang, Kui JiaoAbstract:A sensitive label-free DNA hybridization biosensing platform was fabricated based on the synergistic effect of polyaniline nanotubes (PANInt) and poly-L-lysine (pLys). The composite of pLys and PANInt was coated onto the carbon paste electrode (CPE) to form a uniform and very stable nanocomposite membrane. The pLys in the composite film not only acts as a membrane to retain good electron transfer capability of PANInt even at physiological pH, but also possesses fine biocompatibility for bio-analytes. DNA probes with negatively charged phosphate groups were readily linked to the positively charged pLys surface due to the strong electrostatic affinity. The synergistic effect of PANInt and pLys could significantly enhance the sensitivity of DNA hybridization recognition. The Phosphinothricin Acetyltransferase (PAT) gene fragment from transgenic corn and the polymerase chain reaction amplification of the terminator of nopaline synthase gene from the real sample of a kind of transgenic soybean were detected by this DNA electrochemical biosensor via label-free impedance method. This stable composite gives convenient permselectivity properties as a transducer material for the design of modern electrochemical impedance biosensor using [Fe(CN)6]3−/4− as an indicator.
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electrochemical deoxyribonucleic acid biosensor based on multiwalled carbon nanotubes ag tio2 composite film for label free Phosphinothricin Acetyltransferase gene detection by electrochemical impedance spectroscopy
Chinese Journal of Analytical Chemistry, 2010Co-Authors: Na Zhou, Tao Yang, Kui Jiao, Cai-xia SongAbstract:Abstract A highly sensitive electrochemical deoxyribonucleic acid (DNA) biosensor based on multiwalled carbon nanotubes (MWNT)/Ag-TiO2 composite film was developed. The solution containing Ag-TiO2-MWNT composite was cast on the carbon paste electrode surface to form a robust film, which combined the advantages of the good biocompatibility of Ag-TiO2 composite and the fine conductivity, as well as the large active surface area of carbon nanotubes. The composite could greatly improve the immobilization capacity of the probe DNA. The morphologies and electrochemistry of the nanocomposite film were investigated by scanning electron microscopy and electrochemical techniques including electrochemical impedance spectroscopy and cyclic voltammetry, respectively. DNA hybridization events were monitored by a label-free method of electrochemical impedance spectroscopy. This label-free electrochemical impedance DNA biosensor showed high sensitivity and selectivity for Phosphinothricin Acetyltransferase gene sequence assay. The multicomponents films also displayed a high stability during repeated regeneration and hybridization process.
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Electrochemical Deoxyribonucleic Acid Biosensor Based on Multiwalled Carbon Nanotubes/Ag-TiO2 Composite Film for Label-Free Phosphinothricin Acetyltransferase Gene Detection by Electrochemical Impedance Spectroscopy
Chinese Journal of Analytical Chemistry, 2010Co-Authors: Na Zhou, Tao Yang, Kui Jiao, Cai-xia SongAbstract:Abstract A highly sensitive electrochemical deoxyribonucleic acid (DNA) biosensor based on multiwalled carbon nanotubes (MWNT)/Ag-TiO2 composite film was developed. The solution containing Ag-TiO2-MWNT composite was cast on the carbon paste electrode surface to form a robust film, which combined the advantages of the good biocompatibility of Ag-TiO2 composite and the fine conductivity, as well as the large active surface area of carbon nanotubes. The composite could greatly improve the immobilization capacity of the probe DNA. The morphologies and electrochemistry of the nanocomposite film were investigated by scanning electron microscopy and electrochemical techniques including electrochemical impedance spectroscopy and cyclic voltammetry, respectively. DNA hybridization events were monitored by a label-free method of electrochemical impedance spectroscopy. This label-free electrochemical impedance DNA biosensor showed high sensitivity and selectivity for Phosphinothricin Acetyltransferase gene sequence assay. The multicomponents films also displayed a high stability during repeated regeneration and hybridization process.
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Electrochemical characterization of deoxyribonucleic acid on aluminum(III)/poly(l-glutamic acid) film and its application for the detection of Phosphinothricin Acetyltransferase gene-specific sequence
Thin Solid Films, 2009Co-Authors: Na Zhou, Tao Yang, Chen Jiang, Yongchun Zhang, Kui JiaoAbstract:Abstract A simple strategy of transgenic sequence-specific detection without a special amplification procedure was developed on the basis of aluminum(III)/poly( l -glutamic acid) (PLGA) film. An aluminum ion (Al(III)) thin film was assembled on the surface of PLGA via the electrostatic binding of Al(III) with carboxyl, namely Al(III)/PLGA. The immobilization of deoxyribonucleic acid (DNA) was carried out on this Al(III)/PLGA film by Al(III)-single strand DNA (ssDNA) interaction. Surface hybridization between the immobilized ssDNA and its complementary ssDNA was monitored by electrochemical impedance spectroscopy (EIS) using [Fe(CN) 6 ] 3−/4− as a redox probe. Under the optimal conditions, this DNA electrochemical sensor was applied to determine the specific gene sequence related to Phosphinothricin Acetyltransferase transgene (PAT) in the transgenic plants by label-free EIS.
Horst Lörz - One of the best experts on this subject based on the ideXlab platform.
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fertile transgenictriticale triticosecale wittmack
Molecular Breeding, 1995Co-Authors: Janusz Zimny, Reinhold Brettschneider, Dirk Becker, Horst LörzAbstract:Fertile transgenicTriticale ( ×Triticosecale Wittmack) plants expressing theβ-glucuronidase (uidA) and Phosphinothricin Acetyltransferase (bar) genes were obtained after microprojectile bombardment of scutellar tissue with the plasmid pDB1 containing theuidA gene under the control of the actin-1 promoter (Act1) from rice and the selectable marker genebar under the control of the CaMV 35S promoter. From 465 bombarded scutella about 4000 plantlets were regenerated; 300 plants survived the selection. These regenerants were screened for enzyme activity by the histological GUS assay and by spraying the plants with a herbicide (Basta). Twenty-five regenerants showed GUS activity and survived repeated Basta spraying. Southern blot analysis showed the presence of both marker genes introduced into the genome of analysed plants.
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Fertile, transgenicTriticale ( ×Triticosecale Wittmack)
Molecular Breeding, 1995Co-Authors: Janusz Zimny, Reinhold Brettschneider, Dirk Becker, Horst LörzAbstract:Fertile transgenic Triticale ( × Triticosecale Wittmack) plants expressing the β -glucuronidase ( uidA ) and Phosphinothricin Acetyltransferase ( bar ) genes were obtained after microprojectile bombardment of scutellar tissue with the plasmid pDB1 containing the uidA gene under the control of the actin-1 promoter (Act1) from rice and the selectable marker gene bar under the control of the CaMV 35S promoter. From 465 bombarded scutella about 4000 plantlets were regenerated; 300 plants survived the selection. These regenerants were screened for enzyme activity by the histological GUS assay and by spraying the plants with a herbicide (Basta). Twenty-five regenerants showed GUS activity and survived repeated Basta spraying. Southern blot analysis showed the presence of both marker genes introduced into the genome of analysed plants. All transgenic plants were fertile. They were grown to maturity and set seed. Pollen and progeny analyses provided evidence for inheritance of the introduced genes to the next generation.
Wei Zhang - One of the best experts on this subject based on the ideXlab platform.
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Improved electrochemical performances of polyaniline nanotubes-poly-L-lysine composite for label-free impedance detection of DNA hybridization
Science China Chemistry, 2010Co-Authors: Tao Yang, Wei Zhang, Chen Jiang, Kui JiaoAbstract:A sensitive label-free DNA hybridization biosensing platform was fabricated based on the synergistic effect of polyaniline nanotubes (PANInt) and poly-L-lysine (pLys). The composite of pLys and PANInt was coated onto the carbon paste electrode (CPE) to form a uniform and very stable nanocomposite membrane. The pLys in the composite film not only acts as a membrane to retain good electron transfer capability of PANInt even at physiological pH, but also possesses fine biocompatibility for bio-analytes. DNA probes with negatively charged phosphate groups were readily linked to the positively charged pLys surface due to the strong electrostatic affinity. The synergistic effect of PANInt and pLys could significantly enhance the sensitivity of DNA hybridization recognition. The Phosphinothricin Acetyltransferase (PAT) gene fragment from transgenic corn and the polymerase chain reaction amplification of the terminator of nopaline synthase gene from the real sample of a kind of transgenic soybean were detected by this DNA electrochemical biosensor via label-free impedance method. This stable composite gives convenient permselectivity properties as a transducer material for the design of modern electrochemical impedance biosensor using [Fe(CN)6]3−/4− as an indicator.
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Synergistically improved sensitivity for the detection of specific DNA sequences using polyaniline nanofibers and multi-walled carbon nanotubes composites
Biosensors & bioelectronics, 2008Co-Authors: Tao Yang, Wei Zhang, Na Zhou, Yongchun Zhang, Kui JiaoAbstract:Abstract A sensitive electrochemical DNA biosensor was successfully realized on polyaniline nanofibers (PANI), multi-walled carbon nanotubes (MWNT) and chitosan (CHIT) modified carbon paste electrode (CPE) based on the synergistic effect between PANI and MWNT nanoparticles in chitosan film. PANI and MWNT nanocomposites resulted in highly enhanced electron conductive and biocompatible nanostructured film, which was examined by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The immobilization of the probe DNA on the surface of electrode was largely improved due to the unique synergistic effect of PANI and MWNT. The DNA hybridization events were monitored with an EIS label-free detection strategy. Under the optimal conditions, the dynamic detection range of this DNA electrochemical biosensor was from 1.0 × 10 −13 to 1.0 × 10 −7 mol/L and a detection limit of 2.7 × 10 −14 mol/L for the detection of DNA specific sequence of the Phosphinothricin Acetyltransferase gene (PAT, one of the important screening detection genes for the transgenic plants). Simultaneously, the polymerase chain reaction (PCR) amplification of the terminator of nopaline synthase gene (NOS) from the sample of one kind of genetically modified soybean was also detected satisfactorily.
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dna hybridization and Phosphinothricin Acetyltransferase gene sequence detection based on zirconia nanogold film modified electrode
Applied Surface Science, 2008Co-Authors: Wei Zhang, Tao Yang, Chen Jiang, Kui JiaoAbstract:Abstract This study reports a novel electrochemical DNA biosensor based on zirconia (ZrO 2 ) and gold nanoparticles (NG) film modified glassy carbon electrode (GCE). NG was electrodeposited onto the glassy carbon electrode at 1.5 V, and then zirconia thin film on the NG/GCE was fabricated by cyclic voltammetric method (CV) in an aqueous electrolyte of ZrOCl 2 and KCl at a scan rate of 20 mV/s. DNA probes were attached onto the ZrO 2 /NG/GCE due to the strong binding of the phosphate group of DNA with the zirconia film and the excellent biocompatibility of nanogold with DNA. CV and electrochemical impedance spectroscopy (EIS) were used to characterize the modification of the electrode and the probe DNA immobilization. The electrochemical response of the DNA hybridization was measured by differential pulse voltammetry (DPV) using methylene blue (MB) as the electroactive indicator. After the hybridization of DNA probe (ssDNA) with the complementary DNA (cDNA), the cathodic peak current of MB decreased obviously. The difference of the cathodic peak currents of MB between before and after the hybridization of the probe DNA was used as the signal for the detection of the target DNA. The sequence-specific DNA of Phosphinothricin Acetyltransferase (PAT) gene in the transgenic plants was detected with a detection range from 1.0 × 10 −10 to 1.0 × 10 −6 mol/L, and a detection limit of 3.1 × 10 −11 mol/L.
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Enhanced sensitivity for deoxyribonucleic acid electrochemical impedance sensor: gold nanoparticle/polyaniline nanotube membranes.
Analytica chimica acta, 2008Co-Authors: Yuanyuan Feng, Wei Zhang, Tao Yang, Chen Jiang, Kui JiaoAbstract:Abstract Gold nanoparticle/polyaniline nanotube membranes on the glassy carbon electrode (Au/nanoPAN/GCE) were constructed for the electrochemical sensing of the immobilization and hybridization of DNA. The properties of the Au/nanoPAN/GCE, the characteristics of the immobilization and hybridization of DNA were studied by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. The synergistic effect of the two kinds of nanomaterials, nanogold and nanoPAN, could enhance dramatically the sensitivity for the DNA hybridization recognition. DNA sequence-specific of Phosphinothricin Acetyltransferase gene (PAT) existing in some transgenic crops was detected by electrochemical impedance spectroscopic measurement. The dynamic detection range of the sequence-specific DNA was from 1.0 × 10−12 to 1.0 × 10−6 mol L−1, and the detection limit was 3.1 × 10−13 mol L−1. This biosensor had much wider dynamic detection range and lower detection limit for the DNA detection as compared with other DNA biosensors reported by us. The biosensor also has good selectivity, stability and reproducibility.
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DNA hybridization and Phosphinothricin Acetyltransferase gene sequence detection based on zirconia/nanogold film modified electrode
Applied Surface Science, 2008Co-Authors: Wei Zhang, Tao Yang, Chen Jiang, Kui JiaoAbstract:Abstract This study reports a novel electrochemical DNA biosensor based on zirconia (ZrO 2 ) and gold nanoparticles (NG) film modified glassy carbon electrode (GCE). NG was electrodeposited onto the glassy carbon electrode at 1.5 V, and then zirconia thin film on the NG/GCE was fabricated by cyclic voltammetric method (CV) in an aqueous electrolyte of ZrOCl 2 and KCl at a scan rate of 20 mV/s. DNA probes were attached onto the ZrO 2 /NG/GCE due to the strong binding of the phosphate group of DNA with the zirconia film and the excellent biocompatibility of nanogold with DNA. CV and electrochemical impedance spectroscopy (EIS) were used to characterize the modification of the electrode and the probe DNA immobilization. The electrochemical response of the DNA hybridization was measured by differential pulse voltammetry (DPV) using methylene blue (MB) as the electroactive indicator. After the hybridization of DNA probe (ssDNA) with the complementary DNA (cDNA), the cathodic peak current of MB decreased obviously. The difference of the cathodic peak currents of MB between before and after the hybridization of the probe DNA was used as the signal for the detection of the target DNA. The sequence-specific DNA of Phosphinothricin Acetyltransferase (PAT) gene in the transgenic plants was detected with a detection range from 1.0 × 10 −10 to 1.0 × 10 −6 mol/L, and a detection limit of 3.1 × 10 −11 mol/L.