A label-free and selective aptamer beacon-based Love-wave biosensing device was developed for prostate specific antigen (PSA) detection. The device consists of the following parts: LiTaO3 substrate with SiO2 film as wave guide layer, two set of inter-digital transducers (IDT), gold film for immobilization of the biorecongniton layer and a polydimethylsiloxane (PDMS) microfluidic channels. DNA aptamer, or “artificial antibody”, was used as the specific biorecognition probe for PSA capture. Some nucleotides were added to the 3'-end of the aptamer to form a duplex with the 3'-end, turning the aptamer into an aptamer-beacon. Taking advantage of the selective target-induced assembly changes arising from the “aptamer beacon”, highly selective and specific detection of PSA was achieved. Furthermore, PDMS microfluidic channels were designed and fabricated to realize automated quantitative sample injection. After optimization of the experimental conditions, the established device showed good performance for PSA detection between 10 ng/mL to 1 μg/mL, with a detection limit of 10 ng/mL. The proposed sensor might be a promising alternative for point of care diagnostics.
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机译：开发了一种基于无标记和选择性适体信标的Love-wave生物传感设备，用于前列腺特异性抗原（PSA）检测。该装置由以下部分组成：以SiO 2 膜为波导层的LiTaO 3 衬底，两组叉指式换能器（IDT），用于固定膜的金膜。生物反应层和聚二甲基硅氧烷（PDMS）微流体通道。 DNA适体或“人工抗体”被用作PSA捕获的特异性生物识别探针。将一些核苷酸添加到适体的3'末端以与3'末端形成双链体，从而将适体变成适体信标。利用由“适体信标”引起的选择性靶诱导的装配变化，实现了对PSA的高度选择性和特异性检测。此外，PDMS微流体通道的设计和制造可实现自动化的定量样品进样。在优化实验条件之后，所建立的设备在10 ng / mL到1μg/ mL之间显示出良好的PSA检测性能，检测极限为10 ng / mL。所提出的传感器可能是护理点诊断的有希望的替代方法。
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