Nanobiosensors and Bioanalytical Applications Group (NanoB2A), Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, 08193 Bellaterra, Barcelona, Spain; CIBER-BBN Networking Center on Bioengineering, Biomaterials and Nanomedicine, Spain.
Nanobiosensors and Bioanalytical Applications Group (NanoB2A), Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, 08193 Bellaterra, Barcelona, Spain; CIBER-BBN Networking Center on Bioengineering, Biomaterials and Nanomedicine, Spain.
Biosens Bioelectron. 2017 Oct 15;96:260-267. doi: 10.1016/j.bios.2017.05.020. Epub 2017 May 10.
Nanostructure-based plasmonic biosensors have quickly positioned themselves as interesting candidates for the design of portable optical biosensor platforms considering the potential benefits they can offer in integration, miniaturization, multiplexing, and real-time label-free detection. We have developed a simple integrated nanoplasmonic sensor taking advantage of the periodic nanostructured array of commercial Blu-ray discs. Sensors with two gold film thicknesses (50 and 100nm) were fabricated and optically characterized by varying the oblique-angle of the incident light in optical reflectance measurements. Contrary to the use normal light incidence previously reported with other optical discs, we observed an enhancement in sensitivity and a narrowing of the resonant linewidths as the light incidence angle was increased, which could be related to the generation of Fano resonant modes. The new sensors achieve a figure of merit (FOM) up to 35 RIU and a competitive bulk limit of detection (LOD) of 6.3×10 RIU. These values significantly improve previously reported results obtained with normal light incidence reflectance measurements using similar structures. The sensor has been combined with versatile, simple, ease to-fabricate microfluidics. The integrated chip is only 1cm (including a PDMS flow cell with a 50µm height microfluidic channel fabricated with double-sided adhesive tape) and all the optical components are mounted on a 10cm×10cm portable prototype, illustrating its facile miniaturization, integration and potential portability. Finally, to assess the label-free biosensing capability of the new sensor, we have evaluated the presence of specific antibodies against the GTF2b protein, a tumor-associate antigen (TAA) related to colorectal cancer. We have achieved a LOD in the pM order and have assessed the feasibility of directly measuring biological samples such as human serum.
基于纳米结构的等离子体生物传感器已经迅速成为设计便携式光学生物传感器平台的热门候选者，因为它们在集成、小型化、多路复用和实时无标记检测方面具有潜在的优势。我们利用商业蓝光光盘的周期性纳米结构阵列，开发了一种简单的集成纳米等离子体传感器。制作了两种金膜厚度（50nm 和 100nm）的传感器，并通过改变光学反射率测量中入射光的倾斜角对其进行了光学特性分析。与以前使用其他光盘报告的正常光入射不同，我们观察到随着光入射角的增加，灵敏度增强且共振线宽变窄，这可能与产生的 Fano 共振模式有关。新传感器的品质因数（FOM）高达 35 RIU，竞争的体相检测限（LOD）为 6.3×10 RIU。这些值与使用类似结构的正常光入射反射率测量获得的先前报告结果相比有显著提高。该传感器与多功能、简单、易于制造的微流控装置相结合。集成芯片仅为 1cm（包括一个 PDMS 流池，带有通过双面胶带制造的 50µm 高微流道），所有光学元件都安装在 10cm×10cm 的便携式原型上，说明了其易于小型化、集成和潜在的便携性。最后，为了评估新传感器的无标记生物传感能力，我们评估了针对 GTF2b 蛋白（与结直肠癌相关的肿瘤相关抗原）的特异性抗体的存在。我们实现了 pM 级别的检测限，并评估了直接测量生物样品（如人血清）的可行性。
