Research Center for Applied Sciences, Academia Sinica, No. 128, Section 2, Academic Road, Taipei 11529, Taiwan; Institute of Photonics Technologies, National TsingHua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan.
Research Center for Applied Sciences, Academia Sinica, No. 128, Section 2, Academic Road, Taipei 11529, Taiwan.
Biosens Bioelectron. 2017 May 15;91:580-587. doi: 10.1016/j.bios.2017.01.003. Epub 2017 Jan 7.
A chip-based ultrasensitive surface plasmon resonance (SPR) sensor in a checkerboard nanostructure on plastic substrates is presented for digital detection. The sensing elements on the checkerboard are composed of silver-capped nanoslit arrays, which were fabricated using the thermal-embossing nanoimprint method, to meet the demand for low-cost and rapid fabrication. Sharp Fano resonances in the optimized nanoslit arrays provide high-intensity sensitivities (20,000% per refractive index unit), with an element size of 12.5µm. The polarization-dependent transmission in the checkerboard pattern produces optical isolation between sensing elements and results in a crosstalk lower than 1%. Protein-antibody experiments demonstrated that the digital detection limit was up to 1pg/mL, which is approximately 1000 times lower than that of conventional analog detection. For a 140µm×140µm checkerboard pattern, the dynamic range was approximately 100 times higher than that of conventional surface plasmon resonance measurements. This new digital detection method is very useful for detecting ultralow concentrations of analytes with a nonuniform distribution on the sensor surface.
提出了一种基于芯片的超灵敏表面等离子体共振（SPR）传感器，该传感器采用棋盘状纳米结构，位于塑料衬底上，用于数字检测。棋盘状的传感元件由银覆盖的纳米狭缝阵列组成，这些阵列是使用热压纳米压印方法制造的，以满足低成本和快速制造的需求。优化后的纳米狭缝阵列中存在尖锐的 Fano 共振，提供了高灵敏度（每折射率单位 20000%），元件尺寸为 12.5µm。棋盘图案中的偏振相关传输在传感元件之间产生光学隔离，并且串扰低于 1%。蛋白质-抗体实验表明，数字检测限高达 1pg/mL，比传统的模拟检测低约 1000 倍。对于 140µm×140µm 的棋盘图案，动态范围比传统的表面等离子体共振测量高约 100 倍。这种新的数字检测方法对于检测传感器表面上非均匀分布的超低浓度分析物非常有用。
