The electrochemical behavior of vitamin C（ascorbic acid or AA） is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2＇-（1,2 butanediylbis（nitriloethylidyne））-bis-hyd...The electrochemical behavior of vitamin C（ascorbic acid or AA） is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2＇-（1,2 butanediylbis（nitriloethylidyne））-bis-hydroquinone（BBNBH）.The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA,leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction.This modified electrode exhibits well-separated oxidation peaks for AA and uric acid（UA）.The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.展开更多
In this research, copper oxide nanoparticles modified carbon paste electrode was developed for the voltammetric determination of lidocaine. The square wave voltammogram of lidocaine solution showed a well-defined peak...In this research, copper oxide nanoparticles modified carbon paste electrode was developed for the voltammetric determination of lidocaine. The square wave voltammogram of lidocaine solution showed a well-defined peak between ＋0.5 and ＋1.5 V. Instrumental and chemical parameters influencing voltammetric response were optimized by both one at a time and Box–Behnken model of response surface methodology. The results revealed that there was no significant difference between two methods of optimization. The linear range was 1–2500 μmol L^-1（Ip= 0.11 C（LH）＋ 17.38, R^2= 0.999）. The LOD and LOQ based on three and ten times of the signal to noise（S/N） were 0.39 and 1.3 μmol L^-1（n = 10）,respectively. The precision of the method was assessed for 10 replicate square wave voltammetry（SWV）determinations each of 0.05, 0.5 and 1 μmol L^-1 of lidocaine showing relative standard deviations 4.1%,3.7% and 2.1%, respectively. The reliability of the proposed method was established by application of the method for the determination of lidocaine in two pharmaceutical preparations, namely injection and gel.展开更多
For the resource utilization of the solid waste coking sulfur paste and the improvement of performance of the asphalt mixture,a method for preparing modified asphalt mixture with coking sulfur paste modifier(CSPM)is h...For the resource utilization of the solid waste coking sulfur paste and the improvement of performance of the asphalt mixture,a method for preparing modified asphalt mixture with coking sulfur paste modifier(CSPM)is herein proposed.Compared with the matrix asphalt mixture,the Marshall stability of the 30%CSPM modified asphalt mixture increased by 38.3%,the dynamic stability increased by nearly one time(reaching 1847.5 times/mm),the splitting strength ratio increased by 39.3%while the splitting tensile strength decreased by 11.7%.After curing,the performance of the CSPM modified asphalt mixture was further improved.The results show that CSPM improved the high temperature stability and water damage resistance of the asphalt mixture,and the low-temperature anti-cracking performance of that was slightly reduced.Chemical analysis of asphalt binders shows that a little sulfur reacted with asphalt to produce polysulfide compounds(R-Sx-R′),and a part of sulfur existed in the form of crystalline sulfur which was further increased after curing.The presence of crystalline sulfur as an inorganic filler is the key point for improving the high temperature stability and water resistance performance of modified asphalt mixture.展开更多
A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was de...A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was developed. The DPB was firstly self‐assembled on the Fe3O4NPs, and the re‐sulting Fe3O4NPs/DPB composite was then absorbed on the designed MBCPE. The MBCPE was used to attract the magnetic nanoparticles to the electrode surface. Owing to its high conductivity and large effective surface area, the novel electrode had a very large current response for the electrocat‐alytic oxidation of hydrazine. The modified electrode was characterized by voltammetry, scanning electron microscopy, electrochemical impedance spectroscopy, infrared spectroscopy, and UV‐visible spectroscopy. Voltammetric methods were used to study the electrochemical behaviour of hydrazine on MBCPE/Fe3O4NPs/DPB in phosphate buffer solution （pH = 7.0）. The MBCPE/Fe3O4NPs/DPB, acting as an electrochemical sensor, exhibited very high electrocatalytic activity for the oxidation of hydrazine. The presence of DPB was found to reduce the oxidation potential of hydrazine and increase the catalytic current. The dependence of the electrocatalytic current on the hydrazine concentration exhibited two linear ranges, 0.1–0.4 μmol/L and 0.7–12.0 μmol/L, with a detection limit of 18.0 nmol/L. Additionally, the simultaneous determination of hydrazine and phe‐nol was investigated using the MBCPE/Fe3O4NPs/DPB electrode. Voltammetric experiments showed a linear range of 100–470 μmol/L and a detection limit of 24.3 μmol/L for phenol, and the proposed electrode was applied to the determination of hydrazine and phenol in water samples.展开更多
Objective:To provide a possible basis for the anti-aging effect of modified Qiongyu paste(MQP).Methods:Ultra-high-performance liquid chromatography-Q-Orbitrap mass spectrometry was applied to confirm the effective com...Objective:To provide a possible basis for the anti-aging effect of modified Qiongyu paste(MQP).Methods:Ultra-high-performance liquid chromatography-Q-Orbitrap mass spectrometry was applied to confirm the effective components of MQP that we had identified from databases and research literature.Then,network pharmacology was employed to predict the possible underlying mechanism of MQP against aging.According to the overlap with age-related gene targets,we obtained key targets of MQP against aging using protein-protein interaction analyses.Superoxide dismutase(SOD)tests were performed in vitro and in vivo.Western blotting of P62 and LC3B and quantitative polymerase chain reaction of the expression of the P62,LC3B,HO-1,Keap1,and Nrf2 genes were conducted on H_(2)O_(2) -induced PC12 cells.Enzyme-linked immunosorbent assays of tumor necrosis factor-a and interleukin-6 were conducted on a D-galactose-induced aging mice model.Results:A total of 44 compounds in MQP were finally identified,and 48 gene targets were considered related to anti-aging.Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses linked the principal anti-aging mechanisms of MQP to oxidative resistance,genomic stabilization,and growth hormone regulation.In vitro,H_(2)O_(2)-induced PC12 cells showed that MQP was able to activate SOD,prolong telomeres,and enhance the expression levels of P62,LC3B,HO-1,Keap1,and Nrf2.The quantitative polymerase chain reaction results were affirmed with the reactive oxygen species inhibitor N-acetylcysteine and the reactive oxygen species agonist diallyl-tetrasulfide.In vivo,the D-gal-induced aging mice showed that MQP increased SOD in the brain and reduced tumor necrosis factor-α and interleukin-6 in the serum.Thus,our results suggest that the mechanism of the anti-aging effect of MQP primarily involves antagonizing oxidative stress.Conclusion:From the analyses and experimental validation,we may conclude that oxidative stress resistance may be a potential mechanism of the MQP anti-aging effect.展开更多
The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry w...The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.展开更多
In order to establish a simple,sensitive,and fast reliable detection method to determine the magnolol,FeWO4 nanoflower was synthesised through a solvothermal technique and FeWO4 nanoflower modified carbon paste electr...In order to establish a simple,sensitive,and fast reliable detection method to determine the magnolol,FeWO4 nanoflower was synthesised through a solvothermal technique and FeWO4 nanoflower modified carbon paste electrode（CPE） was developed.The voltammetric behavior of magnolol on the modified electrodes was studied using cyclic voltammetry（CV）,linear sweep voltammetry（LSV）,and differential pulse voltammetry（DPV）.The experimental results showed that the modified electrode remarkably enhanced the electrochemical response of the magnolol and exhibited a wide linear range for determination of the magnolol from 1.0×10-7 to 1.0×10-4 mol/L with a low detection limit of 5.0×10-8 mol/L.展开更多
A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste ele...A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.展开更多
A kind of inorganic organic hybrid 18 molybdodiphosphate nanoparticles ([(C 4H 9) 4N] 6P 2Mo 18 O 62 ·4H 2O) was firstly used as a bulk modifier to fabricate a three dimensional chemically modi...A kind of inorganic organic hybrid 18 molybdodiphosphate nanoparticles ([(C 4H 9) 4N] 6P 2Mo 18 O 62 ·4H 2O) was firstly used as a bulk modifier to fabricate a three dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution was characterized by cyclic and square wave voltammetry. The hybrid 18 molybdodiphosphate nanoparticles bulk modified CPE (MNP CPE) displayed a high electrocatalytic activity towards the reduction of nitrite, bromate and hydrogen peroxide. The remarkable advantages of the MNP CPE over the traditional polyoxometalates modified electrodes are their excellent reproducibility of surface renewal and high stability owing to the insolubility of the hybrid 18 molybdodiphosphate nanoparticles.展开更多
Development of electrochemical DNA hybridization biosensors based on carbon paste electrode （CPE） and gold nanoparticle modified carbon paste electrode （NGMCPE） as transducers and ethyl green （EG） as a new elect...Development of electrochemical DNA hybridization biosensors based on carbon paste electrode （CPE） and gold nanoparticle modified carbon paste electrode （NGMCPE） as transducers and ethyl green （EG） as a new electroac- tive label is described. Electrochemical impedance spectroscopy and cyclic voltammetry techniques were applied for the investigation and comparison of bare CPE and NGMCPE surfaces. Our voltammetric and spectroscopic studies showed gold nanoparticles are enable to facilitate electron transfer between the accumulated label on DNA probe modified electrode and electrode surface and enhance the electrical signals and lead to an improved detection limit. The immobilization of a 15-mer single strand oligonucleotide probe on the working electrodes and hybridiza- tion event between the probe and its complementary sequence as a target were investigated by differential pulse voltammetry （DPV） responses of the EG accumulated on the electrodes. The effects of some experimental variables on the performance of the biosensors were investigated and optimum conditions were suggested. The selectivity of the biosensors was studied using some non-complementary oligonucleotides. Finally the detection limits were calculated as 1.35×10^-10 mol/L and 5.16×10^-11 mol/L on the CPE and NEGCPE, respectively. In addition, the bio-sensors exhibited a good selectivity, reproducibility and stability for the determination of DNA sequences.展开更多
文摘The electrochemical behavior of vitamin C（ascorbic acid or AA） is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2＇-（1,2 butanediylbis（nitriloethylidyne））-bis-hydroquinone（BBNBH）.The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA,leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction.This modified electrode exhibits well-separated oxidation peaks for AA and uric acid（UA）.The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.
基金funding provided by Jundishapur University of Medical Sciences–Nanotechnology Research Center under grant No.N-11
文摘In this research, copper oxide nanoparticles modified carbon paste electrode was developed for the voltammetric determination of lidocaine. The square wave voltammogram of lidocaine solution showed a well-defined peak between ＋0.5 and ＋1.5 V. Instrumental and chemical parameters influencing voltammetric response were optimized by both one at a time and Box–Behnken model of response surface methodology. The results revealed that there was no significant difference between two methods of optimization. The linear range was 1–2500 μmol L^-1（Ip= 0.11 C（LH）＋ 17.38, R^2= 0.999）. The LOD and LOQ based on three and ten times of the signal to noise（S/N） were 0.39 and 1.3 μmol L^-1（n = 10）,respectively. The precision of the method was assessed for 10 replicate square wave voltammetry（SWV）determinations each of 0.05, 0.5 and 1 μmol L^-1 of lidocaine showing relative standard deviations 4.1%,3.7% and 2.1%, respectively. The reliability of the proposed method was established by application of the method for the determination of lidocaine in two pharmaceutical preparations, namely injection and gel.
基金Project(201703D321006)supported by the Shanxi Provincial Key Research and Development Project(Social Development),China。
文摘For the resource utilization of the solid waste coking sulfur paste and the improvement of performance of the asphalt mixture,a method for preparing modified asphalt mixture with coking sulfur paste modifier(CSPM)is herein proposed.Compared with the matrix asphalt mixture,the Marshall stability of the 30%CSPM modified asphalt mixture increased by 38.3%,the dynamic stability increased by nearly one time(reaching 1847.5 times/mm),the splitting strength ratio increased by 39.3%while the splitting tensile strength decreased by 11.7%.After curing,the performance of the CSPM modified asphalt mixture was further improved.The results show that CSPM improved the high temperature stability and water damage resistance of the asphalt mixture,and the low-temperature anti-cracking performance of that was slightly reduced.Chemical analysis of asphalt binders shows that a little sulfur reacted with asphalt to produce polysulfide compounds(R-Sx-R′),and a part of sulfur existed in the form of crystalline sulfur which was further increased after curing.The presence of crystalline sulfur as an inorganic filler is the key point for improving the high temperature stability and water resistance performance of modified asphalt mixture.
文摘A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was developed. The DPB was firstly self‐assembled on the Fe3O4NPs, and the re‐sulting Fe3O4NPs/DPB composite was then absorbed on the designed MBCPE. The MBCPE was used to attract the magnetic nanoparticles to the electrode surface. Owing to its high conductivity and large effective surface area, the novel electrode had a very large current response for the electrocat‐alytic oxidation of hydrazine. The modified electrode was characterized by voltammetry, scanning electron microscopy, electrochemical impedance spectroscopy, infrared spectroscopy, and UV‐visible spectroscopy. Voltammetric methods were used to study the electrochemical behaviour of hydrazine on MBCPE/Fe3O4NPs/DPB in phosphate buffer solution （pH = 7.0）. The MBCPE/Fe3O4NPs/DPB, acting as an electrochemical sensor, exhibited very high electrocatalytic activity for the oxidation of hydrazine. The presence of DPB was found to reduce the oxidation potential of hydrazine and increase the catalytic current. The dependence of the electrocatalytic current on the hydrazine concentration exhibited two linear ranges, 0.1–0.4 μmol/L and 0.7–12.0 μmol/L, with a detection limit of 18.0 nmol/L. Additionally, the simultaneous determination of hydrazine and phe‐nol was investigated using the MBCPE/Fe3O4NPs/DPB electrode. Voltammetric experiments showed a linear range of 100–470 μmol/L and a detection limit of 24.3 μmol/L for phenol, and the proposed electrode was applied to the determination of hydrazine and phenol in water samples.
基金This study was supported by the National Key Research and Development Program of China(2019YFC1710105).
文摘Objective:To provide a possible basis for the anti-aging effect of modified Qiongyu paste(MQP).Methods:Ultra-high-performance liquid chromatography-Q-Orbitrap mass spectrometry was applied to confirm the effective components of MQP that we had identified from databases and research literature.Then,network pharmacology was employed to predict the possible underlying mechanism of MQP against aging.According to the overlap with age-related gene targets,we obtained key targets of MQP against aging using protein-protein interaction analyses.Superoxide dismutase(SOD)tests were performed in vitro and in vivo.Western blotting of P62 and LC3B and quantitative polymerase chain reaction of the expression of the P62,LC3B,HO-1,Keap1,and Nrf2 genes were conducted on H_(2)O_(2) -induced PC12 cells.Enzyme-linked immunosorbent assays of tumor necrosis factor-a and interleukin-6 were conducted on a D-galactose-induced aging mice model.Results:A total of 44 compounds in MQP were finally identified,and 48 gene targets were considered related to anti-aging.Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses linked the principal anti-aging mechanisms of MQP to oxidative resistance,genomic stabilization,and growth hormone regulation.In vitro,H_(2)O_(2)-induced PC12 cells showed that MQP was able to activate SOD,prolong telomeres,and enhance the expression levels of P62,LC3B,HO-1,Keap1,and Nrf2.The quantitative polymerase chain reaction results were affirmed with the reactive oxygen species inhibitor N-acetylcysteine and the reactive oxygen species agonist diallyl-tetrasulfide.In vivo,the D-gal-induced aging mice showed that MQP increased SOD in the brain and reduced tumor necrosis factor-α and interleukin-6 in the serum.Thus,our results suggest that the mechanism of the anti-aging effect of MQP primarily involves antagonizing oxidative stress.Conclusion:From the analyses and experimental validation,we may conclude that oxidative stress resistance may be a potential mechanism of the MQP anti-aging effect.
文摘The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.
基金Funded by the National Natural Science Foundation of China(Nos.21461008 and 21465009)the Open Foundation of Key Laboratory of Biologic Resources Protection and Utilization of Hubei Province,Forestry Key Discipline(No.PKLHB1303)the Hubei University for Nationalities(No.MY2009B007)
文摘In order to establish a simple,sensitive,and fast reliable detection method to determine the magnolol,FeWO4 nanoflower was synthesised through a solvothermal technique and FeWO4 nanoflower modified carbon paste electrode（CPE） was developed.The voltammetric behavior of magnolol on the modified electrodes was studied using cyclic voltammetry（CV）,linear sweep voltammetry（LSV）,and differential pulse voltammetry（DPV）.The experimental results showed that the modified electrode remarkably enhanced the electrochemical response of the magnolol and exhibited a wide linear range for determination of the magnolol from 1.0×10-7 to 1.0×10-4 mol/L with a low detection limit of 5.0×10-8 mol/L.
文摘A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.
文摘A kind of inorganic organic hybrid 18 molybdodiphosphate nanoparticles ([(C 4H 9) 4N] 6P 2Mo 18 O 62 ·4H 2O) was firstly used as a bulk modifier to fabricate a three dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution was characterized by cyclic and square wave voltammetry. The hybrid 18 molybdodiphosphate nanoparticles bulk modified CPE (MNP CPE) displayed a high electrocatalytic activity towards the reduction of nitrite, bromate and hydrogen peroxide. The remarkable advantages of the MNP CPE over the traditional polyoxometalates modified electrodes are their excellent reproducibility of surface renewal and high stability owing to the insolubility of the hybrid 18 molybdodiphosphate nanoparticles.
文摘Development of electrochemical DNA hybridization biosensors based on carbon paste electrode （CPE） and gold nanoparticle modified carbon paste electrode （NGMCPE） as transducers and ethyl green （EG） as a new electroac- tive label is described. Electrochemical impedance spectroscopy and cyclic voltammetry techniques were applied for the investigation and comparison of bare CPE and NGMCPE surfaces. Our voltammetric and spectroscopic studies showed gold nanoparticles are enable to facilitate electron transfer between the accumulated label on DNA probe modified electrode and electrode surface and enhance the electrical signals and lead to an improved detection limit. The immobilization of a 15-mer single strand oligonucleotide probe on the working electrodes and hybridiza- tion event between the probe and its complementary sequence as a target were investigated by differential pulse voltammetry （DPV） responses of the EG accumulated on the electrodes. The effects of some experimental variables on the performance of the biosensors were investigated and optimum conditions were suggested. The selectivity of the biosensors was studied using some non-complementary oligonucleotides. Finally the detection limits were calculated as 1.35×10^-10 mol/L and 5.16×10^-11 mol/L on the CPE and NEGCPE, respectively. In addition, the bio-sensors exhibited a good selectivity, reproducibility and stability for the determination of DNA sequences.
