Jain K K
Jain PharmaBiotech, Basel, Switzerland.
Expert Rev Mol Diagn. 2003 Mar;3(2):153-61. doi: 10.1586/14737159.3.2.153.
Nanotechnology extends the limits of molecular diagnostics to the nanoscale. Nanotechnology-on-a-chip is one more dimension of microfluidic/lab-on-a-chip technology. Biological tests measuring the presence or activity of selected substances become quicker, more sensitive and more flexible when certain nanoscale particles are put to work as tags or labels. Magnetic nanoparticles, bound to a suitable antibody, are used to label specific molecules, structures or microorganisms. Magnetic immunoassay techniques have been developed in which the magnetic field generated by the magnetically labeled targets is detected directly with a sensitive magnetometer. Gold nanoparticles tagged with short segments of DNA can be used for detection of genetic sequence in a sample. Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots into polymeric microbeads. Nanopore technology for analysis of nucleic acids converts strings of nucleotides directly into electronic signatures. DNA nanomachines can function as biomolecular detectors for homogeneous assays. Nanobarcodes, submicrometer metallic barcodes with striping patterns prepared by sequential electrochemical depositon of metal, show differential reflectivity of adjacent stripes enabling identification of the striping patterns by conventional light microscopy. All this has applications in population diagnostics and in point-of-care hand-held devices.
纳米技术将分子诊断的极限扩展到了纳米尺度。芯片上的纳米技术是微流控/芯片实验室技术的又一个维度。当某些纳米级颗粒用作标记物或标签时，测量特定物质的存在或活性的生物测试会变得更快、更灵敏且更灵活。与合适抗体结合的磁性纳米颗粒用于标记特定分子、结构或微生物。已经开发出磁性免疫分析技术，其中通过灵敏的磁力计直接检测由磁性标记靶标产生的磁场。用短段DNA标记的金纳米颗粒可用于检测样品中的基因序列。通过将不同大小的量子点嵌入聚合物微珠中，实现了生物测定的多色光学编码。用于核酸分析的纳米孔技术将核苷酸串直接转化为电子信号。DNA纳米机器可作为用于均相测定的生物分子探测器。纳米条形码是通过金属的顺序电化学沉积制备的具有条纹图案的亚微米级金属条形码，相邻条纹具有不同的反射率，能够通过传统光学显微镜识别条纹图案。所有这些在群体诊断和即时检测手持设备中都有应用。
