Researchers have shown significant interest in modulating the peroxidase-like activity of nanozymes.Among these,bimetallic nanozymes have shown superior peroxidase-like activity over monometallic counterparts,offering...Researchers have shown significant interest in modulating the peroxidase-like activity of nanozymes.Among these,bimetallic nanozymes have shown superior peroxidase-like activity over monometallic counterparts,offering enhanced performance and cost-efficiency in nanozyme designs.Herein,bimetallic nanozymes comprising nickel(Ni)and osmium(Os)incorporated into hyaluronate(HA)have been developed,resulting in HA-Nin/Os nanoclusters.Subsequently,comprehensive characterizations have been conducted.Further investigation has revealed that HA-Nin/Os efficiently catalyzed 3,3,5,5-tetramethylbenzidine(TMB)oxidation with hydrogen peroxide(H_(2)O_(2)),confirming its peroxidase-like behavior and role as a nanozyme.Impressively,HA-Ni_(2)/Os(Ni/Os=2:1)displays heightened substrate affinity,accelerated reaction rates,enhanced hydroxyl radical production in acidic conditions,and exhibits activity unit of 1224 U/mg,representing more than two-fold increase compared to non-Ni-supported Os nanozyme.Theoretical calculations indicate that Ni support enhances the peroxidase-like process of Os nanozyme by improving H_(2)O_(2) adsorption and TMB oxidation.Crucially,the support of Ni does not significantly alter the other enzyme-like activities of Os nanozymes,thereby enabling Ni to selectively enhance their peroxidase-like activity.In terms of application,the peroxidase-like ability of HA-Ni_(2)/Os,facilitated by HA's carboxyl groups enabling crosslinking,proves effective in a squamous carcinoma antigen immunoassay.Moreover,HA-Ni_(2)/Os exhibit reliable stability,promising as a peroxidase substitute.This work underscores the advantages of incorporating Ni into Os,specifically enhancing peroxidase-like activity,highlighting the potential of Os bimetallic nanozymes for peroxidase-based applications.展开更多
Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitori...Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitoring.Nevertheless,challenges still exist in detecting ultra-low concentration analytes due to the inherent sensitivity limitations of LFIA.Recently,significant advances have been achieved by integrating enzyme activity probes and transforming LFIA into a highly sensitive tool for rapidly detecting trace analyte concentrations.Specifically,modifying natural enzymes or engineered nanozymes allows them to function as immune probes,directly catalyzing the production of signal molecules or indirectly initiating enzyme activity.Therefore,the signal intensity and detection sensitivity of LFIA are markedly elevated.The present review undertakes a comprehensive examination of pertinent research literature,offering a systematic analysis of recently proposed enzyme-based signal amplification strategies.By way of comparative assessment,the merits and demerits of current approaches are delineated,along with the identification of research avenues that still need to be explored.It is anticipated that this critical overview will garner considerable attention within the biomedical and materials science communities,providing valuable direction and insight toward the advancement of high-performance LFIA technologies.展开更多
The advancement of various types of fluorescent nanoparticles is crucial for enhancing the application of lateral flow immunoassays(LFIA)across multiple fields.Currently,the fluorescent nanoparticles utilized in LFIA ...The advancement of various types of fluorescent nanoparticles is crucial for enhancing the application of lateral flow immunoassays(LFIA)across multiple fields.Currently,the fluorescent nanoparticles utilized in LFIA predominantly consist of traditional dye-doped nanoparticles or aggregation-induced luminescence dye-doped nanoparticles.The reliance on specific types of nanoparticles limits the diversity of signal reporting groups available for LFIA.Herein,we developed a solid-state luminescent dye-doped nanoparticles(SLDNPs)-based LFIA system with exceptional stability for the detection of C-reactive protein(CRP)in serum.The synthesis of SLD_(520)NP_(S)was simplicity,efficient and eco-friendly,which was ideal for large-scale production of the LFIA test strip.And the SLD_(520)NP_(S)exhibits superior fluorescence quantum yield(49%),fully guarantees the performance of the LFIA test strip.The constructed SLD_(520)NPsm Ab1-based LFIA demonstrated a satisfactory linear relationship with CRP concentrations ranging from 0.5 ng/mL to 100 ng/mL,with limits of detection(LOD)of 0.78 ng/mL and a visible LOD of 1 ng/mL using a handheld 405 nm lamp.Furthermore,the developed LFIA exhibited excellent recoveries in serum,ranging from 94.45%to 102.5%.Overall,the outstanding performance of the SLD_(520)NPs-mAb1-based LFIA indicates that solid-state luminescent dyes have significant potential applications in the field of LFIA.展开更多
Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,...Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,we reported a liposome-mediated signal-off photoelectrochemical(PEC)immunoassay for the sensitive detection of carcinoembryonic antigen(CEA)using ternary transition metal sulfide CuS/ZnCdS as the photoactive material.Good photocurrents were acquired on the basis of specific oxidation reaction of dopamine on the CuS/ZnCdS.The energy band relationship of CuS/ZnCdS was determined,and the wellmatched oxidation potential of dopamine was verified.To achieve accurate recovery of low-abundance CEA,systematic PEC evaluation from human serum samples was performed by combining with classical immunoreaction and liposome-induced dopamine amplification strategy with high stability and selectivity.Under optimum conditions,PEC immunoassay displayed good photocurrent responses toward target CEA with a dynamic linear range of 0.1-50 ng/mL with a detection limit of 31.6 pg/mL.Importantly,this system by combining with a discussion of energy level matching between semiconductor energy bands and small-molecules opens a new horizon for development of high-efficient PEC immunoassays.展开更多
This study aimed to establish a highly accurate method for quantifying methotrexate(MTX)concentrations in serum using an ultra-high performance liquid chromatography-tandem mass spectrometry system(UPLC-MS/MS)and to c...This study aimed to establish a highly accurate method for quantifying methotrexate(MTX)concentrations in serum using an ultra-high performance liquid chromatography-tandem mass spectrometry system(UPLC-MS/MS)and to compare its performance with the chemiluminescence microparticle immunoassay(CMIA).A total of 211 serum samples from pediatric patients with intracranial tumors undergoing high-dose MTX treatment were analyzed using both techniques.Correlation and agreement analyses were performed to assess the level of concordance between these methods.The results demonstrated a significant correlation(P<0.05)between the two methods,with correlation coefficients of 0.9913 and 0.9893,respectively.However,a statistical difference was noted in MTX serum concentrations at lower levels(0.04-1.5μmol/L),while no significant difference was observed at higher concentrations(1.5-400μmol/L).Specifically,in the 0.04-1.5μmol/L range(107 cases),Bland-Altman analysis indicated a bias of 0.018 between the two methods.Given the observed discrepancies,particularly at lower concentrations,it is advised that the UPLC-MS/MS method should not be used interchangeably with the CMIA assay for therapeutic drug monitoring in patients receiving high-dose MTX treatment.展开更多
We report the development of a triplex nucleic acid lateral flow immunoassay(NALFIA)for the detection of the genomes of Nipah virus(NiV),Middle East respiratory syndrome coronavirus(MERS-CoV)and Reston ebolavirus(REBO...We report the development of a triplex nucleic acid lateral flow immunoassay(NALFIA)for the detection of the genomes of Nipah virus(NiV),Middle East respiratory syndrome coronavirus(MERS-CoV)and Reston ebolavirus(REBOV),which are intended for screening bats as well as other hosts and reservoirs of these three viruses.Our triplex NALFIA is a two-step assay format:the target nucleic acid in the sample is first amplified using tagged primers,and the tagged dsDNA amplicons are captured by antibodies immobilized on the NALFIA device,resulting in signal development from the binding of a streptavidin-colloidal gold conjugate to a biotin tag on the captured amplicons.Triplex amplification of the N gene of NiV,the UpE gene of MERS-CoV,and the Vp40 gene of REBOV was optimized,and three compatible combinations of hapten labels and antibodies were identified for end point detection.The lowest RNA copy numbers detected by the triplex NALFIA were 8.21e4 for the NiV N target,7.09e1 for the MERS-CoV UpE target,and 1.83e4 for the REBOV Vp40 target.Using simulated samples,the sensitivity and specificity for MERS-CoV and REBOV targets were estimated to be 100%,while the sensitivity and specificity for the NiV target were 91%and 93.3%,respectively.The compliance rate between triplex NALFIA and real-time RT‒PCR was 92%for the NiV N target and 100%for the MERS-CoV UpE and REBOV Vp40 targets.展开更多
Immunoassay technology is an analytical method with high sensitivity and specificity; it provides a technique to assay materials which cannot be measured by other methods, or are difficult to detect. It plays a very i...Immunoassay technology is an analytical method with high sensitivity and specificity; it provides a technique to assay materials which cannot be measured by other methods, or are difficult to detect. It plays a very important role in biological sample pre-treatment, therapeutic drug monitoring and drug determination, and is one of the important means for in vivo drug analyses. This paper reviews immunoassays commonly used in bioanalysis, including immunoextraction and immunodepletion for pretreatment of biological samples, conventional immunoassay methods and new immunoassay technologies for determination of target drugs.展开更多
A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP). PNPP is enzymatically hydrolyzed and the product p-nitrophenol (P...A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP). PNPP is enzymatically hydrolyzed and the product p-nitrophenol (PNP) is detected by differential pulse voltammetry (DPV), which can be oxidized at +1.02 V (vs. Ag/AgCl) on bare glass carbon electrode (GCE). The conditions for enzymatic reaction and electrochemical detection were studied. According to this method, ALP can be detected with a detection limit of 2.8102 mU/L and a linear range of 4.0102 ~ 1.0106 mU/L.展开更多
This paper described a new immunoassay method by capillary electrophoresis with enhanced chemiluminescence (CL) detection system based on luminol-hydrogen peroxide reaction catalyzed by horseradish peroxides (HRP). Us...This paper described a new immunoassay method by capillary electrophoresis with enhanced chemiluminescence (CL) detection system based on luminol-hydrogen peroxide reaction catalyzed by horseradish peroxides (HRP). Using para-iodophenol as a CL enhancer, the detection limit of about 1×10-12 mol/L for HRP was achieved, which corresponded to 1.32×10-5 U/mL. In optimal conditions, the free HRP-labeled CA125 antibody (Ab*) and the bound enzyme-labeled complex (Ab*-Ag) were well separated by capillary electrophoresis within 4 min. The assay was successfully used to determine the contents of CA125 in human sera, which were associated with ovarian cancer, and the recoveries of the standard addition experiments were 96 to 109 %.展开更多
基金financial support from the Natural Science Foundation of Fujian Province(No.2022J01271)the Joint Funds for the Innovation of Science and Technology,Fujian Province(No.2023Y9226)+1 种基金the Introduced High-Level Talent Team Project of Quanzhou City(No.2023CT008)the Doctoral Research Foundation Project of the Second Affiliated Hospital of Fujian Medical University(No.BS202201)。
文摘Researchers have shown significant interest in modulating the peroxidase-like activity of nanozymes.Among these,bimetallic nanozymes have shown superior peroxidase-like activity over monometallic counterparts,offering enhanced performance and cost-efficiency in nanozyme designs.Herein,bimetallic nanozymes comprising nickel(Ni)and osmium(Os)incorporated into hyaluronate(HA)have been developed,resulting in HA-Nin/Os nanoclusters.Subsequently,comprehensive characterizations have been conducted.Further investigation has revealed that HA-Nin/Os efficiently catalyzed 3,3,5,5-tetramethylbenzidine(TMB)oxidation with hydrogen peroxide(H_(2)O_(2)),confirming its peroxidase-like behavior and role as a nanozyme.Impressively,HA-Ni_(2)/Os(Ni/Os=2:1)displays heightened substrate affinity,accelerated reaction rates,enhanced hydroxyl radical production in acidic conditions,and exhibits activity unit of 1224 U/mg,representing more than two-fold increase compared to non-Ni-supported Os nanozyme.Theoretical calculations indicate that Ni support enhances the peroxidase-like process of Os nanozyme by improving H_(2)O_(2) adsorption and TMB oxidation.Crucially,the support of Ni does not significantly alter the other enzyme-like activities of Os nanozymes,thereby enabling Ni to selectively enhance their peroxidase-like activity.In terms of application,the peroxidase-like ability of HA-Ni_(2)/Os,facilitated by HA's carboxyl groups enabling crosslinking,proves effective in a squamous carcinoma antigen immunoassay.Moreover,HA-Ni_(2)/Os exhibit reliable stability,promising as a peroxidase substitute.This work underscores the advantages of incorporating Ni into Os,specifically enhancing peroxidase-like activity,highlighting the potential of Os bimetallic nanozymes for peroxidase-based applications.
基金Financial supports from the National Natural Science Foundation of China(NSFC,Nos.52272144 and 22205048)Heilongjiang Provincial Natural Science Foundation of China(No.JQ2022E001)+3 种基金China Postdoctoral Science Foundation(Nos.2022M710931 and 2023T160154)Heilongjiang Postdoctoral Science Foundation(No.LBH-Z22010)Natural Science Foundation of Shandong Province(No.ZR2020ZD42)the Fundamental Research funds for the Central Universities are greatly acknowledged.
文摘Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitoring.Nevertheless,challenges still exist in detecting ultra-low concentration analytes due to the inherent sensitivity limitations of LFIA.Recently,significant advances have been achieved by integrating enzyme activity probes and transforming LFIA into a highly sensitive tool for rapidly detecting trace analyte concentrations.Specifically,modifying natural enzymes or engineered nanozymes allows them to function as immune probes,directly catalyzing the production of signal molecules or indirectly initiating enzyme activity.Therefore,the signal intensity and detection sensitivity of LFIA are markedly elevated.The present review undertakes a comprehensive examination of pertinent research literature,offering a systematic analysis of recently proposed enzyme-based signal amplification strategies.By way of comparative assessment,the merits and demerits of current approaches are delineated,along with the identification of research avenues that still need to be explored.It is anticipated that this critical overview will garner considerable attention within the biomedical and materials science communities,providing valuable direction and insight toward the advancement of high-performance LFIA technologies.
基金supported by the National Natural Science Foundation of China(Nos.22064014,21765013)the Science and Technology Development Plan Project of Lanzhou(No.20211-146)+3 种基金the Science and Technology Project of Gansu Province(Nos.21YF5FA071,21JR7RA538)the Industrial Support Programme for Higher Education Institutions Project(Nos.2023CYZC-69,2024CYCZ-05)the 2023 Gansu Provincial Key Talent Project(No.2023RCXM26)a Gansu province postdoctoral grant(No.00247)。
文摘The advancement of various types of fluorescent nanoparticles is crucial for enhancing the application of lateral flow immunoassays(LFIA)across multiple fields.Currently,the fluorescent nanoparticles utilized in LFIA predominantly consist of traditional dye-doped nanoparticles or aggregation-induced luminescence dye-doped nanoparticles.The reliance on specific types of nanoparticles limits the diversity of signal reporting groups available for LFIA.Herein,we developed a solid-state luminescent dye-doped nanoparticles(SLDNPs)-based LFIA system with exceptional stability for the detection of C-reactive protein(CRP)in serum.The synthesis of SLD_(520)NP_(S)was simplicity,efficient and eco-friendly,which was ideal for large-scale production of the LFIA test strip.And the SLD_(520)NP_(S)exhibits superior fluorescence quantum yield(49%),fully guarantees the performance of the LFIA test strip.The constructed SLD_(520)NPsm Ab1-based LFIA demonstrated a satisfactory linear relationship with CRP concentrations ranging from 0.5 ng/mL to 100 ng/mL,with limits of detection(LOD)of 0.78 ng/mL and a visible LOD of 1 ng/mL using a handheld 405 nm lamp.Furthermore,the developed LFIA exhibited excellent recoveries in serum,ranging from 94.45%to 102.5%.Overall,the outstanding performance of the SLD_(520)NPs-mAb1-based LFIA indicates that solid-state luminescent dyes have significant potential applications in the field of LFIA.
基金financial support from the National Natural Science Foundation of China(Nos.22274022 and 21874022).
文摘Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,we reported a liposome-mediated signal-off photoelectrochemical(PEC)immunoassay for the sensitive detection of carcinoembryonic antigen(CEA)using ternary transition metal sulfide CuS/ZnCdS as the photoactive material.Good photocurrents were acquired on the basis of specific oxidation reaction of dopamine on the CuS/ZnCdS.The energy band relationship of CuS/ZnCdS was determined,and the wellmatched oxidation potential of dopamine was verified.To achieve accurate recovery of low-abundance CEA,systematic PEC evaluation from human serum samples was performed by combining with classical immunoreaction and liposome-induced dopamine amplification strategy with high stability and selectivity.Under optimum conditions,PEC immunoassay displayed good photocurrent responses toward target CEA with a dynamic linear range of 0.1-50 ng/mL with a detection limit of 31.6 pg/mL.Importantly,this system by combining with a discussion of energy level matching between semiconductor energy bands and small-molecules opens a new horizon for development of high-efficient PEC immunoassays.
基金The Science and Technology Fund of Beijing Shijitan Hospital(Grant No.2022-C06)the National Key Research and Development Program of China(Grant No.2020YFF01014606).
文摘This study aimed to establish a highly accurate method for quantifying methotrexate(MTX)concentrations in serum using an ultra-high performance liquid chromatography-tandem mass spectrometry system(UPLC-MS/MS)and to compare its performance with the chemiluminescence microparticle immunoassay(CMIA).A total of 211 serum samples from pediatric patients with intracranial tumors undergoing high-dose MTX treatment were analyzed using both techniques.Correlation and agreement analyses were performed to assess the level of concordance between these methods.The results demonstrated a significant correlation(P<0.05)between the two methods,with correlation coefficients of 0.9913 and 0.9893,respectively.However,a statistical difference was noted in MTX serum concentrations at lower levels(0.04-1.5μmol/L),while no significant difference was observed at higher concentrations(1.5-400μmol/L).Specifically,in the 0.04-1.5μmol/L range(107 cases),Bland-Altman analysis indicated a bias of 0.018 between the two methods.Given the observed discrepancies,particularly at lower concentrations,it is advised that the UPLC-MS/MS method should not be used interchangeably with the CMIA assay for therapeutic drug monitoring in patients receiving high-dose MTX treatment.
基金funded by the Department of Biotechnology,Ministry of Science and Technology,Government of India(DBT)under grant number ADMaC DBT-NER/LIVS/11/2012.
文摘We report the development of a triplex nucleic acid lateral flow immunoassay(NALFIA)for the detection of the genomes of Nipah virus(NiV),Middle East respiratory syndrome coronavirus(MERS-CoV)and Reston ebolavirus(REBOV),which are intended for screening bats as well as other hosts and reservoirs of these three viruses.Our triplex NALFIA is a two-step assay format:the target nucleic acid in the sample is first amplified using tagged primers,and the tagged dsDNA amplicons are captured by antibodies immobilized on the NALFIA device,resulting in signal development from the binding of a streptavidin-colloidal gold conjugate to a biotin tag on the captured amplicons.Triplex amplification of the N gene of NiV,the UpE gene of MERS-CoV,and the Vp40 gene of REBOV was optimized,and three compatible combinations of hapten labels and antibodies were identified for end point detection.The lowest RNA copy numbers detected by the triplex NALFIA were 8.21e4 for the NiV N target,7.09e1 for the MERS-CoV UpE target,and 1.83e4 for the REBOV Vp40 target.Using simulated samples,the sensitivity and specificity for MERS-CoV and REBOV targets were estimated to be 100%,while the sensitivity and specificity for the NiV target were 91%and 93.3%,respectively.The compliance rate between triplex NALFIA and real-time RT‒PCR was 92%for the NiV N target and 100%for the MERS-CoV UpE and REBOV Vp40 targets.
文摘目的参加血清淀粉样蛋白A(serum amyloid A,SAA)第2代国际标准品(international standard,IS)候选品(编号:23/148)的协作定值研究。方法按照英国药品健康产品管理局(Medicines and Healthcare products Regulatory Agency,MHRA)研究方案,中国食品药品检定研究院代表中国实验室,组织了12家实验室(包括生产企业或检测机构),采用6种化学发光免疫分析法和6种胶乳免疫比浊法检测试剂盒进行标定。结果中国实验室提交的SAA免疫效价几何均值为56.3μg/安瓿[95%置信区间为52.2~60.6μg/安瓿,n=12,几何变异系数(geometric coefficient of variation,GCV)为12.6%],中位值为53.8μg/安瓿(95%置信区间为51.9~61.1μg/安瓿)。全球6个国家共17个实验室参加了本次研究,经分析,全部数据得到的SAA免疫效价几何均值为60.9μg/安瓿(95%置信区间为54.6~67.9μg/安瓿,n=17,GCV为23.5%),中位值为55.8μg/安瓿(95%置信区间为52.0~60.0μg/安瓿)。结论经世界卫生组织(World Health Organization,WHO)生物标准专家委员会审核通过,确定候选品可作为第2代SAA IS使用,以中位数(56μg/安瓿)结果作为最终定值结果。但上述协作标定数据提示目前商业化SAA免疫测定的协调性较差,试剂盒生产商在过渡到使用23/148时可能受到不利影响,必要时需重新校准其测定,以改善检测结果间的一致性。
基金National Natural Science Foundation of China(Gr ant No.81102499)Hunan Science and Technology Project(Grant No.2011SK3261)
文摘Immunoassay technology is an analytical method with high sensitivity and specificity; it provides a technique to assay materials which cannot be measured by other methods, or are difficult to detect. It plays a very important role in biological sample pre-treatment, therapeutic drug monitoring and drug determination, and is one of the important means for in vivo drug analyses. This paper reviews immunoassays commonly used in bioanalysis, including immunoextraction and immunodepletion for pretreatment of biological samples, conventional immunoassay methods and new immunoassay technologies for determination of target drugs.
基金The work was supported by the National Natural Science Foundation of China(Grant No.20075013)the Natural Science Foundation of Shandong Province(Grant No.Y98B06025).
文摘A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP). PNPP is enzymatically hydrolyzed and the product p-nitrophenol (PNP) is detected by differential pulse voltammetry (DPV), which can be oxidized at +1.02 V (vs. Ag/AgCl) on bare glass carbon electrode (GCE). The conditions for enzymatic reaction and electrochemical detection were studied. According to this method, ALP can be detected with a detection limit of 2.8102 mU/L and a linear range of 4.0102 ~ 1.0106 mU/L.
基金supported by the National Natural Science Foundation of China(No.20271033)the key project of National Natural Science Foundation of China(No.20335020)Natural Science Foundation of Shanghai(No.02ZA14057).
文摘This paper described a new immunoassay method by capillary electrophoresis with enhanced chemiluminescence (CL) detection system based on luminol-hydrogen peroxide reaction catalyzed by horseradish peroxides (HRP). Using para-iodophenol as a CL enhancer, the detection limit of about 1×10-12 mol/L for HRP was achieved, which corresponded to 1.32×10-5 U/mL. In optimal conditions, the free HRP-labeled CA125 antibody (Ab*) and the bound enzyme-labeled complex (Ab*-Ag) were well separated by capillary electrophoresis within 4 min. The assay was successfully used to determine the contents of CA125 in human sera, which were associated with ovarian cancer, and the recoveries of the standard addition experiments were 96 to 109 %.
基金基金项目:国家重点基础研究发展计划(973计划)资助项目(2011CB933202)中围科学院战略性先导科技专项课题资助项目(XDA06020101)+3 种基金国家杰出青年自然基金资助项目(61125105)国家高技术研究发展计划(863计划)资助项目(2009AA03Z411)中国科学院科研装备研制资助项目(Y2010015)国家自然科学基金资助项目(61027001,61002037).Acknowledgements This work was supported by the Major National Scientific Research Plan (No.2011CB933202), "Strategic Priority Research Program" of the Chinese Academy of Sciences (No.XDA06020101), the National Science Fund for Distinguished Young Scholar (No. 61125105), the Hi-Tech R&D Program of China (No. 2009AA03Z411), the CAS Program (No.Y2010015) and the National Natural Science Foundation of China (No. 61027001, No. 61002037).