Soelberg Scott D, Chinowsky Timothy, Geiss Gary, Spinelli Charles B, Stevens Richard, Near Steve, Kauffman Peter, Yee Sinclair, Furlong Clement E
Department of Genome Science, Division of Medical Genetics, University of Washington, P.O. Box 357720, Seattle, WA 98195-7720, USA.
J Ind Microbiol Biotechnol. 2005 Dec;32(11-12):669-74. doi: 10.1007/s10295-005-0044-5. Epub 2005 Nov 11.
Many environmental applications exist for biosensors capable of providing real-time analyses. One pressing current need is monitoring for agents of chemical- and bio-terrorism. These applications require systems that can rapidly detect small organics including nerve agents, toxic proteins, viruses, spores and whole microbes. A second area of application is monitoring for environmental pollutants. Processing of grab samples through chemical laboratories requires significant time delays in the analyses, preventing the rapid mapping and cleanup of chemical spills. The current state of development of miniaturized, integrated surface plasmon resonance (SPR) sensor elements has allowed for the development of inexpensive, portable biosensor systems capable of the simultaneous analysis of multiple analytes. Most of the detection protocols make use of antibodies immobilized on the sensor surface. The Spreeta 2000 SPR biosensor elements manufactured by Texas Instruments provide three channels for each sensor element in the system. A temperature-controlled two-element system that monitors for six analytes is currently in use, and development of an eight element sensor system capable of monitoring up to 24 different analytes will be completed in the near future. Protein toxins can be directly detected and quantified in the low picomolar range. Elimination of false positives and increased sensitivity is provided by secondary antibodies with specificity for different target epitopes, and by sensor element redundancy. Inclusion of more than a single amplification step can push the sensitivity of toxic protein detection to femtomolar levels. The same types of direct detection and amplification protocols are used to monitor for viruses and whole bacteria or spores. Special protocols are required for the detection of small molecules. Either a competition type assay where the presence of analyte inhibits the binding of antibodies to surface-immobilized analyte, or a displacement assay, where antibodies bound to analyte on the sensor surface are displaced by free analyte, can be used. The small molecule detection assays vary in sensitivity from the low micromolar range to the high picomolar.
能够进行实时分析的生物传感器有许多环境应用。当前一个紧迫需求是监测化学和生物恐怖主义制剂。这些应用需要能够快速检测包括神经毒剂、有毒蛋白质、病毒、孢子和完整微生物在内的小分子有机物的系统。第二个应用领域是监测环境污染物。通过化学实验室处理采集样本在分析过程中需要很长时间延迟，这阻碍了对化学泄漏的快速测绘和清理。小型化、集成表面等离子体共振（SPR）传感器元件的当前发展状态使得能够开发出能够同时分析多种分析物的廉价、便携式生物传感器系统。大多数检测方案利用固定在传感器表面的抗体。德州仪器制造的Spreeta 2000 SPR生物传感器元件为系统中的每个传感器元件提供三个通道。目前正在使用一个监测六种分析物的温度控制双元件系统，并且一个能够监测多达24种不同分析物的八元件传感器系统将在不久的将来完成开发。蛋白质毒素可以在低皮摩尔范围内直接检测和定量。针对不同靶抗原决定簇具有特异性的二抗以及传感器元件冗余提供了假阳性的消除和灵敏度的提高。包含不止一个扩增步骤可以将有毒蛋白质检测的灵敏度提高到飞摩尔水平。相同类型的直接检测和扩增方案用于监测病毒以及完整细菌或孢子。检测小分子需要特殊方案。可以使用竞争型检测，即分析物的存在抑制抗体与表面固定分析物的结合，或者置换检测，即传感器表面与分析物结合的抗体被游离分析物置换。小分子检测分析的灵敏度范围从低微摩尔到高皮摩尔不等。
