Waitkus Jacob, Park JaeWoo, Ndukaife Theodore, Yang Sui, Du Ke
Chemical and Environmental Engineering, University of California Riverside, Riverside, CA 92521, USA.
Material Science and Engineering, School for Engineering of Matter, Transport and Energy Arizona State University, Tempe, AZ85281, USA.
Adv Mater Interfaces. 2025 Jun 9;12(11). doi: 10.1002/admi.202400945. Epub 2025 Mar 31.
This study demonstrates a biosensing platform facilitated by localized surface plasmonic resonance (LSPR) on a silicon (Si) nanopillar metasurface mediated by the presence of cephalexin (Cef) antibiotics in solution. The metasurface is designed to exhibit narrow quadrupolar Mie resonances that when coupled with bovine serum albumin-coated (BSA-coated) plasmonic gold nanospheres (BSANS) will produce an appreciable redshift at the peak resonance wavelength, occurring only in the presence of the target antibiotic. To optimize the performance of the Si nanopillars, the finite element method is utilized to fine-tune their diameters, heights, and periodicity, along with improvements to the fabrication techniques, under the BSANS-antibiotic binding assay. The metasurface sensor is directly fabricated via a facile photolithographic process using silicon wafers. Through the detection assay, this device exhibited a significant 22 nm wavelength shift resulting from changes to the local refractive index in the presence of the BSANS-antibiotic coupling. This phenomenon is facilitated through the presence of cephalexin down to 0.3 μg mL for the binding between the plasmonic nanoparticles and the metasurface allowing for sensitive and real-time detection.
本研究展示了一种生物传感平台，该平台由溶液中头孢氨苄（Cef）抗生素的存在介导，在硅（Si）纳米柱超表面上通过局域表面等离子体共振（LSPR）实现。该超表面被设计为呈现窄的四极米氏共振，当与牛血清白蛋白包覆（BSA包覆）的等离子体金纳米球（BSANS）耦合时，将在峰值共振波长处产生明显的红移，且仅在目标抗生素存在时出现。为了优化硅纳米柱的性能，在BSANS - 抗生素结合测定中，利用有限元方法对其直径、高度和周期性进行微调，并改进制造技术。该超表面传感器通过使用硅片的简便光刻工艺直接制造。通过检测测定，该装置在存在BSANS - 抗生素耦合时，由于局部折射率的变化呈现出显著的22 nm波长偏移。这种现象通过头孢氨苄的存在得以实现，其浓度低至0.3 μg/mL时，等离子体纳米颗粒与超表面之间的结合实现了灵敏且实时的检测。
