Beiderman Marianna, Ashkenazy Ariel, Segal Elad, Motiei Menachem, Salomon Adi, Sadan Tamar, Fixler Dror, Popovtzer Rachela
Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel.
Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel.
ACS Omega. 2021 Oct 22;6(43):29071-29077. doi: 10.1021/acsomega.1c04301. eCollection 2021 Nov 2.
Nanoplasmonic biosensors incorporating noble metal nanocavity arrays are widely used for the detection of various biomarkers. Gold nanorods (GNRs) have unique properties that can enhance spectroscopic detection capabilities of such nanocavity-based biosensors. However, the contribution of the physical properties of multiple GNRs to resonance enhancement of gold nanocavity arrays requires further characterization and elucidation. In this work, we study how GNR aspect ratio (AR) and surface area (SA) modify the plasmonic resonance spectrum of a gold triangular nanocavity array by both simulations and experiments. The finite integration technique (FIT) simulated the extinction spectrum of the gold nanocavity array with 300 nm periodicity onto which the GNRs of different ARs and SAs are placed. Simulations showed that matching of the GNRs longitudinal peak, which is affected by AR, to the nanocavity array's spectrum minima can optimize signal suppression and shifting. Moreover, increasing SA of the matched GNRs increased the spectral variations of the array. Experiments confirmed that GNRs conjugated to a gold triangular nanocavity array of 300 nm periodicity caused spectrum suppression and redshift. Our findings demonstrate that tailoring of the GNR AR and SA parameters to nanoplasmonic arrays has the potential to greatly improve spectral variations for enhanced plasmonic biosensing.
包含贵金属纳米腔阵列的纳米等离子体生物传感器被广泛用于检测各种生物标志物。金纳米棒（GNRs）具有独特的性质，能够增强此类基于纳米腔的生物传感器的光谱检测能力。然而，多个金纳米棒的物理性质对金纳米腔阵列共振增强的贡献需要进一步表征和阐明。在这项工作中，我们通过模拟和实验研究了金纳米棒的纵横比（AR）和表面积（SA）如何改变金三角形纳米腔阵列的等离子体共振光谱。有限积分技术（FIT）模拟了具有300 nm周期性的金纳米腔阵列的消光光谱，不同纵横比和表面积的金纳米棒被放置在该阵列上。模拟结果表明，受纵横比影响的金纳米棒纵向峰值与纳米腔阵列光谱最小值的匹配可以优化信号抑制和位移。此外，匹配的金纳米棒表面积的增加会增加阵列的光谱变化。实验证实，与具有300 nm周期性的金三角形纳米腔阵列共轭的金纳米棒会导致光谱抑制和红移。我们的研究结果表明，根据纳米等离子体阵列调整金纳米棒的纵横比和表面积参数有可能极大地改善光谱变化，以增强等离子体生物传感。
