基因传感技术及目前存在的问题和发展对策

对最近几年报道的比较有特色的光学、压电、电化学等基因(DNA)传感器方面的研究工作进行介绍,并就目前基因传感器研究中存在的问题进行了分析讨论,提出了相应的发展对策.     

三螺旋脱氧核糖核酸的研究进展

阐述了三螺旋DNA的发展和最新动态,并从3个方面展开评述：(1)三螺旋DNA稳定性的研究。三螺旋DNA的稳定性不仅取决于寡聚核苷酸的内在结构,还受外界环境如溶液的pH值、阳离子的种类和价态、DNA分子嵌入试剂和共聚物等的影响;(2)三螺旋DNA的应用。三螺旋DNA的形成为基因操纵和基因疗法提供了新方法,它在抑制DNA转录、复制、基因定点诱变、定点切割和诱导基因重组等方面有重要的应用前景;(3)三螺旋DNA的检测方法,包括紫外-可见吸收光谱法、荧光分析法、原子力显微术和顺磁共振谱等。     

毛细管电泳-激光诱导荧光法分离检测DNA片段及基因扩增产物

以羟丙甲基纤维素和非交联聚丙烯酰胺浴液为筛分介质,将毛细管电泳-激光诱导荧光法用于DNA片段及基因扩增产物的分离检测。探讨了非胶筛分介质中高分子化合物的浓度、电解质的浓度、内插试剂用量等对DNA片段分离检测的影响;考察了DNA片段迁移时间和峰面积的重现性及DNA片段定量检测的关系。建立了一种快速、灵敏的DNA片段及基因扩增产物分离检测方法。     

DNA修饰电极的研究(ⅠΧ)——DNA探针在金基底上的固定、表征及其表面分子杂交

采用巯基化合物自组装 /共价键合反应的逐层固定方法将双链 DNA固定到金表面得到 DNA修饰电极 ,并对该电极表面进行了电化学和 X射线光电子能谱表征 .研究了电极表面固定化 DNA的表面分子杂交 .对开发电化学基因诊断芯片和基因传感器具有一定意义     

结构DNA纳米技术

DNA简单的配对原理A-T/C-G创造了丰富多彩的生物世界。DNA纳米技术将DNA从传统的基因图计划拓展成为建筑模块,用以构建功能纳米结构。本文综述了DNA自组装的原理,以及近年来结构DNA纳米技术研究中一些令人鼓舞的进展,其中包括构建二维和三维DNA纳米结构,以及DNA引导的多组分二维和三维纳米结构的最新成果,并对其研究前沿进行了展望。     

脱氧核糖核酸在硬脂酸铝离子膜上固定杂交及BAR基因片段检测

将石墨粉、固体石蜡和硬脂酸按一定比例混合制得表面富含羧基的碳糊电极,然后在电极表面组装荷正电的铝离子膜。在硬脂酸铝离子膜上进行DNA探针的固定和与目标基因的杂交。以亚甲蓝为杂交指示剂,用循环伏安法优化了DNA的固定和杂交条件。应用该电化学生物传感器以微分脉冲伏安法对转基因玉米外源BAR基因片段进行了检测,结果令人满意。     

DNA修饰电极的研究(Ⅸ)--DNA探针在金基底上的固定、表征及其表面分子杂交

采用疏基化合的自组装／共价键合反应的逐层固定方法将双链DNA固定到金表面得到DNA修饰电极,并对该电极表面进行了电化学和X射线光电子能谱表征。研究了电极表面固定化DNA的表面分子杂交。对开发电化学基因诊断芯片和基因传感器具有一定意义。     

IL-24重组载体的构建及其联合化疗药物对SKOV3细胞中TUBB3与ERCC-1基因表达的影响

通过基因重组技术将白介素24(IL-24)基因片段分别克隆成pc DNA3.0-OSP-1-IL-24和pc DNA3.0-IL-24载体,利用逆转录PCR(RT-PCR)测定2种载体的表达.将2种化疗药物紫杉醇(PTX)与顺铂(DDP)分别作用于正常SKOV3细胞及pc DNA3.0,pc DNA3.0-IL-24,pc DNA3.0-OSP-1和pc DNA3.0-OSP-1-IL-24稳定转染SKOV3细胞(卵巢癌细胞株),通过噻唑蓝(MTT)法检测化疗药物联合IL-24基因对细胞的杀伤效果及细胞的增殖能力,应用实时荧光定量PCR技术检测人β-微管蛋白3(TUBB3)与核苷酸切除修复交叉互补基因位1(ERCC1)基因在各组细胞中的表达.RT-PCR检测结果显示,通过基因重组技术克隆了pc DNA3.0-IL-24与pc DNA3.0-OSP-1-IL-24载体,IL-24基因能提高SKOV3细胞对化疗药物顺铂和紫杉醇的敏感性.其联合化疗药物对肿瘤药物的IC50值分别下降了10倍和6倍,TUBB3和ERCC1基因在IL-24基因转染的SKOV3细胞内的表达水平与在正常SKOV3细胞内相比,分别下降4倍和10倍多.上述结果表明,IL-24联合化疗药物可明显下调TUBB3与ERCC1基因的表达,该实验为临床治疗卵巢癌提供了重要的理论依据.     

DNA分子识别及传感技术

DNA杂交生物传感器为基因的识别及疾病的诊断提供了一种快速,简便,廉价的方法,此文从DNA的固定及检测技术两个方面,举例介绍了各不同方式的研究应用现状及对传感器灵敏度,杂交专一性,杂交速度及使用寿命的影响,对DNA识别技术的发展前景进行了展望。     

基于双纳米金探针杂交法检测HBV DNA

利用双纳米金探针结合基因芯片平台建立了一种检测乙肝病毒基因(HBV DNA)的新方法. 根据HBV DNA的保守序列设计捕获探针和信号报告探针, 通过一对互补的纳米金检测探针的双杂交法对HBV DNA进行信号放大, 最后进行银染, 达到对HBV DNA的可视化检测. 该方法的灵敏度高, 可检测10 fmol/L的HBV DNA, 且能在1.5 h内完成检测. 其具有的快速、 高灵敏度及低成本等优势使其有望发展成为一种检测HBV DNA的新方法.     

纳米粒子在电化学DNA生物传感器研究中的应用

简要介绍了电化学DNA生物传感器的原理和分类,对纳米粒子在电化学DNA生物传感器研究中的应用进行了详细评述.     

脱氧核糖核酸电分析化学研究进展

就DNA电分析化学研究及其应用方面进行综述，主要叙述了DNA的各种电分析化学方法，以及DNA电化学传感器的原理，应用以及发展，本文引用文献77篇。     

脱氧核糖核酸在电极表面的固定化研究进展

介绍了电化学脱氧核糖核酸(DNA)传感器的原理并重点评述了DNA在不同材料电极表面的固定化技术,对比了吸附法、自组装法、亲和素一生物素法、共价键合法以及组合法固定DNA在构建电化学DNA传感器中的应用。参考文献77篇。     

Functionalized carbon nanotubes and nanofibers for biosensing applications

This review summarizes recent advances in electrochemical biosensors based on carbon nanotubes (CNTs) and carbon nanofibers (CNFs) with an emphasis on applications of CNTs. CNTs and CNFs have unique electric, electrocatalytic and mechanical properties, which make them efficient materials for developing electrochemical biosensors.We discuss functionalizing CNTs for biosensors. We review electrochemical biosensors based on CNTs and their various applications (e.g., measurement of small biological molecules and environmental pollutants, detection of DNA, and immunosensing of disease biomarkers). Moreover, we outline the development of electrochemical biosensors based on CNFs and their applications. Finally, we discuss some future applications of CNTs.     

Applications of peptide nucleic acids (PNAs) and locked nucleic acids (LNAs) in biosensor development

Nucleic acid biosensors have a growing number of applications in genetics and biomedicine. This contribution is a critical review of the current state of the art concerning the use of nucleic acid analogues, in particular peptide nucleic acids (PNA) and locked nucleic acids (LNA), for the development of high-performance affinity biosensors. Both PNA and LNA have outstanding affinity for natural nucleic acids, and the destabilizing effect of base mismatches in PNA- or LNA-containing heterodimers is much higher than in double-stranded DNA or RNA. Therefore, PNA- and LNA-based biosensors have unprecedented sensitivity and specificity, with special applicability in DNA genotyping. Herein, the most relevant PNA- and LNA-based biosensors are presented, and their advantages and their current limitations are discussed. Some of the reviewed technology, while promising, still needs to bridge the gap between experimental status and the harder reality of biotechnological or biomedical applications.     

纳米材料在电化学生物传感器及生物电分析领域中的应用

纳米尺度上的生物分析化学是当今国际生物分析领域研究的前沿和热点.该文阐述了纳米粒子在电化学免疫传感器及电化学DNA传感器领域的应用,着重介绍了以纳米材料为载体设计新型的具有生物分子识别和电信号增强作用的纳米标记粒子在构建高灵敏电化学生物传感器以及多组分同时检测中的应用.     

Analytical applications of Raman spectroscopy

In this article interaction of transition metal complexes with DNA and its applications in electrochemical DNA biosensors as hybridization indicator or electroactive marker of DNA are reviewed. Special emphasis has been given to the efforts for the development of new transition metal complexes and their interaction to DNA. DNA and polymers covalently conjugated with transition metal complexes were also reviewed.     

Label-Free Impedance Biosensors: Opportunities and Challenges

Impedance biosensors are a class of electrical biosensors that show promise for point-of-care and other applications due to low cost, ease of miniaturization, and label-free operation. Unlabeled DNA and protein targets can be detected by monitoring changes in surface impedance when a target molecule binds to an immobilized probe. The affinity capture step leads to challenges shared by all label-free affinity biosensors; these challenges are discussed along with others unique to impedance readout. Various possible mechanisms for impedance change upon target binding are discussed. We critically summarize accomplishments of past label-free impedance biosensors and identify areas for future research.     

Recent developments, characteristics, and potential applications of electrochemical biosensors.

The objective of this study is to analyze the technical importance, performance, techniques, advantages, and disadvantages of the biosensors in general and of the electrochemical biosensors in particular. A product of reaction diffuses to the transducer in the first generation biosensors (based on Clark biosensors). The mediated biosensors or second generation biosensors use specific mediators between the reaction and the transducer to improve sensitivity. The second generation biosensors involve two steps: first, there is a redox reaction between enzyme and substrate that is reoxidized by the mediator, and eventually the mediator is oxidized by the electrode. No normal product or mediator diffusion is directly involved in the third generation biosensors, direct biosensors. Based on the type of transducer, current biosensors are divided into optical, mass, thermal, and electrochemical sensors. They are used in medical diagnostics, food quality controls, environmental monitoring, and other applications. These biosensors are also grouped under two broad categories of sensors: direct and indirect detection systems. Moreover, these systems could be further grouped into continuous or batch operation. Therefore, amperometric biosensors and their current applications are focused on more in detail since they are the most commonly used biosensors in monitoring and diagnosing tests in clinical analysis. Problems related to the commercialization of medical, environmental, and industrial biosensors as well as their performance characteristics, their competitiveness in comparison to the conventional analytical tools, and their costs determine the future development of these biosensors.     

Electrochemistry of Nucleic Acids at Solid Electrodes and Its Applications

The knowledge of the redox chemistry of nucleic acids (NA) is of paramount importance in cancer and aging research. Charge migration through DNA is also involved in biologically relevant functions such as DNA damage and repair. In the first part of this article the main aspects of the electrochemistry of nucleic acids at solid electrodes are revised, including redox processes, photoelectroactivity and electrical conductivity. In the second part, an overview of its applications is presented. Methods for electrochemical detection of NA, NA‐based biosensors for detection of nonnucleic acid molecules, studies on the nature and dynamics of interactions and structural conformations of NA, are some applications that take advantage of NA electrochemistry at solid electrodes.