A simple one-step hydrothermal method is used to prepare an enzyme-free photoelectric combined glucose sensor based on TiO_(2)NRs/FTO with low cost,sample two-electrode,and excellent detection.Under 380 nm light(0.5 m...A simple one-step hydrothermal method is used to prepare an enzyme-free photoelectric combined glucose sensor based on TiO_(2)NRs/FTO with low cost,sample two-electrode,and excellent detection.Under 380 nm light(0.5 mW cm^(−2))irradiation and a positive voltage,holes are accumulated on TiO_(2)NRs surface,catalyzing glucose and forming a photocurrent without the need for an enzyme,such as Glucose oxidase(GOx).The designed sensor exhibits high sensitivity(about 0.96μA mM^(−1)cm^(−2),without GOx)and excellent linear relationship in the glucose concentration range of 5–15 mML^(−1).The prepared glucose sensor performs better with a sensitivity of 1.48μA mM^(−1)cm^(−2)when a certain amount of GOx is mixed in the detected solution.In addition,the sensor has excellent anti-interference resistance to non-reducing chitosan and reducing ascorbic acid with short response time(less than 5 s);thus,it can be used in quick detection with a double electrode system.This sensing device has the advantages of simple fabrication,easy storage,and reusability;therefore,it can be very promising in the portable and rapid monitoring of human blood glucose levels.展开更多
Cu-based metal organic frameworks(MOFs)are regarded as promising sensing materials,which have abundant metal sites,large surface area and simple synthesis processes.In this work,a novel three-dimensional flower-like C...Cu-based metal organic frameworks(MOFs)are regarded as promising sensing materials,which have abundant metal sites,large surface area and simple synthesis processes.In this work,a novel three-dimensional flower-like Cu-MOF was synthesized,which was combined with ultra-thin MXene nanosheets to construct a novel electrochemical sensor for H_(2)O_(2).展开更多
Main observation and conclusion An enzyme-free amperometric sensor based on a heptadecapeptide possessing an electroactive ferrocene(Fc)linker as ferrocene-Gly-Gly-Gly-Gly-Phe-Gly-His-Ile-His-Glu-Gly-Tyr-Gly-Gly-Gly-G...Main observation and conclusion An enzyme-free amperometric sensor based on a heptadecapeptide possessing an electroactive ferrocene(Fc)linker as ferrocene-Gly-Gly-Gly-Gly-Phe-Gly-His-Ile-His-Glu-Gly-Tyr-Gly-Gly-Gly-Gly-Lys-(CH_(2))_(4)-dithiocyclopentane self-assembled on gold substrate was designed and fabricated for specific determination of L-arginine(L-Arg).The detection mechanism is based on conformational change of surface-immobilized peptide induced by the target L-Arg,which was confirmed via SEM,TEM,AFM,XPS,and SPR studies.The binding affinity and the recognition feasibility of immobilized specific and non-specific peptides were also assessed using electrochemical impedance spectroscopy(EIS),cyclic voltammetry(CV),and differential pulse voltammetry(DPV).The proposed method can serve as“signal-on”sensor for detection of L-Arg down to 31 pmol/L with broad linear range(0.0001 to 10μmol/L).Furthermore,the Fc-conjugated specific peptide sensor was successfully applied to the determination of L-Arg in pig serums with a recovery rate of 97.5%—106.9%,and its test results are in good agreement with that of chromatographic instrument,evidencing that the oligopeptide-based sensor can be served as a simple and enzyme-free biosensing platform towards L-Arg for future application.展开更多
Due to the fact that most microRNAs are small in size,low abundance in biological samples,homologous sequence among family members,and protein enzymes-based strategies display limited practical applications,therefore,...Due to the fact that most microRNAs are small in size,low abundance in biological samples,homologous sequence among family members,and protein enzymes-based strategies display limited practical applications,therefore,we reported a simple enzyme-free DNA sensor for microRNA detection utilizing a multiple signal amplification strategy.The sensing system termed as C-CHA-HCR includes six hairpin DNA reactants that are metastable on account of intramolecular hybridization.The DNA hairpin reactants are opened and hybridized with the corresponding complementary DNA strand in the presence of miR-21 via toehold-mediated CHA,HCR reaction,and circulation between CHA and HCR,resulting in a hugely amplifying signal output.Without introducing external protein enzymes,this sensing system showed highly sensitive and selective on the detection of miR-21.A linear response range of miR-21 from 25 pmol/L to 1 nmol/L with a limit of detection(LOD)of 1.8 pmol/L was obtained.This promising biosensor was successfully applied to the detection of microRNA in human serum samples with acceptable recovery rates,suggesting the potential applications in disease diagnosis,treatment,and prognosis.展开更多
In this work,we have developed a sensitive,simple,and enzyme-free assay for detection of micro RNAs(mi RNAs)by means of a DNA molecular motor consisting of two stem-loop DNAs with identical stems and complementary loo...In this work,we have developed a sensitive,simple,and enzyme-free assay for detection of micro RNAs(mi RNAs)by means of a DNA molecular motor consisting of two stem-loop DNAs with identical stems and complementary loop domains.In the presence of mi RNA target,it can hybridize with one of the stem-loop DNA to open the stem and to produce a mi RNA/DNA hybrid and a single strand(ss)DNA,the ss DNA will in turn hybridize with another stem-loop DNA and finally form a double strand(ds)DNA to release the mi RNA.One of the stem-loop DNA is double-labeled by a fluorophore/quencher pair with efficiently quenched fluorescence.The formation of ds DNA can produced specific fluorescence signal for mi RNA detection.The released mi RNA will continuously initiate the next hybridization of the two stem-loop DNAs to form a cycle-running DNA molecular motor,which results in great fluorescence amplification.With the efficient signal amplification,as low as 1 pmol/L mi RNA target can be detected and a wide dynamic range from 1 pmol/L to 2 nmol/L is also obtained.Moreover,by designing different stem-loop DNAs specific to different mi RNA targets and labeling them with different fluorophores,multiplexed mi RNAs can be simultaneously detected in one-tube reaction with the synchronous fluorescence spectrum(SFS)technique.展开更多
Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large sur...Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.展开更多
基金supported by the National Natural Science Foundation of China(51972055,21561031,22004087,and 81803480)the Guangdong Basic and Applied Basic Research Foundation(2020A1515010258 and 2019A1515110926)+5 种基金the Stable Support Project for Shenzhen High Education Institutions(SZWD2021001)the Shenzhen Science and Technology Innovation Commission(JCYJ20190809145601651)the Common University Innovation Team Project of Guangdong(2021KCXTD041)Shenzhen Bay Laboratory Open Program(SZBL2020090501002)the Central Government for Guiding Local Science and Technology Development Program(elevation of magnetic imaging guided nano-theranosis capability)and the Natural Science Foundation of Top Talent of SZTU(20200201 and 20200202).
文摘A simple one-step hydrothermal method is used to prepare an enzyme-free photoelectric combined glucose sensor based on TiO_(2)NRs/FTO with low cost,sample two-electrode,and excellent detection.Under 380 nm light(0.5 mW cm^(−2))irradiation and a positive voltage,holes are accumulated on TiO_(2)NRs surface,catalyzing glucose and forming a photocurrent without the need for an enzyme,such as Glucose oxidase(GOx).The designed sensor exhibits high sensitivity(about 0.96μA mM^(−1)cm^(−2),without GOx)and excellent linear relationship in the glucose concentration range of 5–15 mML^(−1).The prepared glucose sensor performs better with a sensitivity of 1.48μA mM^(−1)cm^(−2)when a certain amount of GOx is mixed in the detected solution.In addition,the sensor has excellent anti-interference resistance to non-reducing chitosan and reducing ascorbic acid with short response time(less than 5 s);thus,it can be used in quick detection with a double electrode system.This sensing device has the advantages of simple fabrication,easy storage,and reusability;therefore,it can be very promising in the portable and rapid monitoring of human blood glucose levels.
基金This work was financially supported by the National Key Research and Development Program of China(No.2016YFA0203101)the National Natural Science Foundation of China(Nos.21974042,21904039,21874080,21645008,21621003,21622506)+1 种基金the Sci-entific Research Fund of Hunan Provincial Education Department(No.18A010)the Science and Technology Department of Hunan Province(Nos.14JJ4030,2020JJ5352).
文摘Cu-based metal organic frameworks(MOFs)are regarded as promising sensing materials,which have abundant metal sites,large surface area and simple synthesis processes.In this work,a novel three-dimensional flower-like Cu-MOF was synthesized,which was combined with ultra-thin MXene nanosheets to construct a novel electrochemical sensor for H_(2)O_(2).
基金supported by the projects of the National Natural Science Foundation of China(Nos.31527803,21545010,21275022 and 21645009)the Natural Science Foundation of Hunan Province,China(Nos.2020JJ4599,2019JJ50651).
文摘Main observation and conclusion An enzyme-free amperometric sensor based on a heptadecapeptide possessing an electroactive ferrocene(Fc)linker as ferrocene-Gly-Gly-Gly-Gly-Phe-Gly-His-Ile-His-Glu-Gly-Tyr-Gly-Gly-Gly-Gly-Lys-(CH_(2))_(4)-dithiocyclopentane self-assembled on gold substrate was designed and fabricated for specific determination of L-arginine(L-Arg).The detection mechanism is based on conformational change of surface-immobilized peptide induced by the target L-Arg,which was confirmed via SEM,TEM,AFM,XPS,and SPR studies.The binding affinity and the recognition feasibility of immobilized specific and non-specific peptides were also assessed using electrochemical impedance spectroscopy(EIS),cyclic voltammetry(CV),and differential pulse voltammetry(DPV).The proposed method can serve as“signal-on”sensor for detection of L-Arg down to 31 pmol/L with broad linear range(0.0001 to 10μmol/L).Furthermore,the Fc-conjugated specific peptide sensor was successfully applied to the determination of L-Arg in pig serums with a recovery rate of 97.5%—106.9%,and its test results are in good agreement with that of chromatographic instrument,evidencing that the oligopeptide-based sensor can be served as a simple and enzyme-free biosensing platform towards L-Arg for future application.
基金supported by the National Natural Science Foundation of China(21874042,21974042).
文摘Due to the fact that most microRNAs are small in size,low abundance in biological samples,homologous sequence among family members,and protein enzymes-based strategies display limited practical applications,therefore,we reported a simple enzyme-free DNA sensor for microRNA detection utilizing a multiple signal amplification strategy.The sensing system termed as C-CHA-HCR includes six hairpin DNA reactants that are metastable on account of intramolecular hybridization.The DNA hairpin reactants are opened and hybridized with the corresponding complementary DNA strand in the presence of miR-21 via toehold-mediated CHA,HCR reaction,and circulation between CHA and HCR,resulting in a hugely amplifying signal output.Without introducing external protein enzymes,this sensing system showed highly sensitive and selective on the detection of miR-21.A linear response range of miR-21 from 25 pmol/L to 1 nmol/L with a limit of detection(LOD)of 1.8 pmol/L was obtained.This promising biosensor was successfully applied to the detection of microRNA in human serum samples with acceptable recovery rates,suggesting the potential applications in disease diagnosis,treatment,and prognosis.
基金the National Natural Science Foundation of China(21335005,21472120)the Fundamental Research Funds for the Central Universities(GK201501003,GK201303003)the Excellent Doctor Innovation Project of Shaanxi Normal University
文摘In this work,we have developed a sensitive,simple,and enzyme-free assay for detection of micro RNAs(mi RNAs)by means of a DNA molecular motor consisting of two stem-loop DNAs with identical stems and complementary loop domains.In the presence of mi RNA target,it can hybridize with one of the stem-loop DNA to open the stem and to produce a mi RNA/DNA hybrid and a single strand(ss)DNA,the ss DNA will in turn hybridize with another stem-loop DNA and finally form a double strand(ds)DNA to release the mi RNA.One of the stem-loop DNA is double-labeled by a fluorophore/quencher pair with efficiently quenched fluorescence.The formation of ds DNA can produced specific fluorescence signal for mi RNA detection.The released mi RNA will continuously initiate the next hybridization of the two stem-loop DNAs to form a cycle-running DNA molecular motor,which results in great fluorescence amplification.With the efficient signal amplification,as low as 1 pmol/L mi RNA target can be detected and a wide dynamic range from 1 pmol/L to 2 nmol/L is also obtained.Moreover,by designing different stem-loop DNAs specific to different mi RNA targets and labeling them with different fluorophores,multiplexed mi RNAs can be simultaneously detected in one-tube reaction with the synchronous fluorescence spectrum(SFS)technique.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Nos.51671003,21802003,21571112)Natural Science Foundation of Shandong Province(ZR2018BB031)+3 种基金the Shandong Taishan Scholar Program(H.W.)the China Postdoctoral Science Foundation(No.2017M610022)the start-up supports from Peking UniversityYoung Thousand Talented Program。
文摘Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.
