Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy.
Centre of Excellence for Biomedical Research, University of Genoa, viale Benedetto XV 9, 16132 Genoa, Italy.
Sensors (Basel). 2020 Mar 13;20(6):1615. doi: 10.3390/s20061615.
The continuous advances of Nanofluidics have been stimulating the development of novel nanostructures and strategies to accumulate very diluted analytes, for implementing a new class of high sensitivity miniaturized polymeric sensors. We take advantage of the electrokinetic properties of these structures, which allow accumulating analytes inside asymmetric microfluidic structures to implement miniaturized sensors able to detect diluted solutions down to nearly 1.2 pg/mL. In particular, exploiting polydimethylsiloxane devices, fabricated by using the junction gap breakdown technique, we concentrate antigens inside a thin microfunnel functionalized with specific antibodies to favor the interaction and, if it is the case, the recognition between antigens in solution and antibodies anchored to the surface. The transduction mechanism consists in detecting the fluorescence signal of labeled avidin when it binds to biotinylated antigens. Here, we demonstrate that exploiting these electrokinetic phenomena, typical of nanofluidic structures, we succeeded in concentrating biomolecules in correspondence of a 1 pL sensing region, a strategy that grants to the device performance comparable to standard immunoassays.
纳流技术的不断进步刺激了新型纳米结构和策略的发展，以积累非常稀释的分析物，从而实现一类新型的高灵敏度微型聚合物传感器。我们利用这些结构的电动特性，允许在非对称微流结构内积累分析物，以实现能够检测稀释溶液至近 1.2 pg/mL 的微型传感器。具体来说，我们利用结间隙击穿技术制造的聚二甲基硅氧烷器件，将抗原浓缩在一个薄的微漏斗中，该微漏斗用特异性抗体进行功能化，以促进抗原与表面锚定的抗体之间的相互作用和（如果有的话）识别。转导机制包括检测标记的亲和素与生物素化抗原结合时的荧光信号。在这里，我们证明利用这些电动现象，即纳流结构的典型特征，我们成功地将生物分子浓缩在 1 pL 的传感区域内，这种策略使该器件的性能可与标准免疫测定相媲美。
