Schüler Thomas, Asmus Tim, Fritzsche Wolfgang, Möller Robert
JBCI, Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.
Biosens Bioelectron. 2009 Mar 15;24(7):2077-84. doi: 10.1016/j.bios.2008.10.028. Epub 2008 Nov 12.
The fast development in the field of DNA analytics is driven by the need for cost-effective and high-throughput methods for the detection of biomolecules. The detection of DNA using metal nanoparticles as labels is an interesting alternative to the standard fluorescence technique. Fluorescence is highly sensitive and broadly established, but shows limitations, for example instability of the signal and the requirement for sophisticated and high-cost equipment. A recently developed approach realizes a method for the electrical detection of DNA, based on the induction of silver nanoparticles growth in microelectrode gaps on the surface of a DNA-chip. This breakthrough towards robust and cost-effective detection was still hampered by the need for microstructured (and therefore expensive) substrates. We demonstrate that it is possible to utilize screen printed electrode structures for a chip-based electrical DNA detection. The electrode structures were produced on a glass substrate which made an additional optical readout possible. The screen printed structures show the required precision and are compatible with the applied biochemical protocols. A comparison with chip substrates produced by standard photolithography showed the same sensitivity and specificity for the screen printed chips. Screen printing of electrode structures for DNA-chip with electrical detection offers an interesting and cost-efficient possibility to produce DNA-chips with microstructured electrodes.
DNA分析领域的快速发展是由对生物分子检测的经济高效且高通量方法的需求所驱动的。使用金属纳米颗粒作为标记来检测DNA是标准荧光技术的一种有趣替代方法。荧光检测高度灵敏且广泛应用，但也存在局限性，例如信号不稳定以及需要复杂且昂贵的设备。最近开发的一种方法实现了基于DNA芯片表面微电极间隙中银纳米颗粒生长的感应来对DNA进行电学检测。尽管这一朝着稳健且经济高效检测方向的突破仍因需要微结构化（因而昂贵）的底物而受到阻碍。我们证明利用丝网印刷电极结构进行基于芯片的电学DNA检测是可行的。电极结构是在玻璃基板上制作的，这使得额外的光学读出成为可能。丝网印刷结构显示出所需的精度，并且与所应用的生化方案兼容。与通过标准光刻法生产的芯片基板进行比较表明，丝网印刷芯片具有相同的灵敏度和特异性。用于具有电学检测功能的DNA芯片的电极结构的丝网印刷为生产具有微结构化电极的DNA芯片提供了一种有趣且经济高效的可能性。
