Chen Cheng-Chuan, Lo Shu-Cheng, Wei Pei-Kuen
Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
Institute of Applied Mechanics, National Taiwan University, Taipei 11529, Taiwan.
Nanomaterials (Basel). 2021 Dec 29;12(1):88. doi: 10.3390/nano12010088.
Label-free surface plasmon resonance (SPR) detection of mercuric ions in various aqueous solutions, using capped gold nanoslit arrays combined with electrochemical (EC) sensing technique, is demonstrated. The nanoslit arrays are fabricated on flexible cyclo-olefin polymer substrates by a nanoimprinting lithography method. The EC and SPR signals for the investigation of current responses and transmission SPR spectra are simultaneously measured during metal ions electrodeposition. Glycerol-water solution is studied to evaluate the resonant peak wavelength sensitivity (480.3 nm RIU) with a FOM of 40.0 RIU and the obtained intensity sensitivity is 1819.9%. The ferrocyanide/ferricyanide redox couple performs the diffusion controlled electrochemical processes ( = 0.99). By investigating the SPR intensity changes and wavelength shifts of various mercuric ion concentrations, the optical properties are evaluated under chronoamperometric conditions. The sensors are evaluated in the detection range between 100 μM and 10 nM with a detection limit of 1 μM. The time dependence of SPR signals and the selectivity of 10 μM Hg in the presence of 10 μM interfering metal ion species from Ca, Co, Ni, Na, Cu, Pb and Mn are determined. The capped gold nanoslit arrays show the selectivity of Hg and the EC sensing method is effectively utilized to aqueous Hg detection. This study provides a label-free detection technique of mercuric ions and this developed system is potentially applicable to detecting chemicals and biomolecules.
本文展示了一种使用封端金纳米狭缝阵列结合电化学（EC）传感技术，对各种水溶液中的汞离子进行无标记表面等离子体共振（SPR）检测的方法。纳米狭缝阵列通过纳米压印光刻法制备在柔性环烯烃聚合物基板上。在金属离子电沉积过程中，同时测量用于研究电流响应和透射SPR光谱的EC和SPR信号。研究了甘油 - 水溶液，以评估其共振峰波长灵敏度（480.3 nm/RIU），其品质因数为40.0 RIU，获得的强度灵敏度为1819.9%。亚铁氰化物/铁氰化物氧化还原对进行扩散控制的电化学过程（ = 0.99）。通过研究不同汞离子浓度下的SPR强度变化和波长偏移，在计时电流法条件下评估光学性质。该传感器在100 μM至10 nM的检测范围内进行评估，检测限为1 μM。确定了SPR信号的时间依赖性以及在存在来自Ca、Co、Ni、Na、Cu、Pb和Mn的10 μM干扰金属离子物种时10 μM Hg的选择性。封端金纳米狭缝阵列显示出对Hg的选择性，并且EC传感方法有效地用于水溶液中Hg的检测。本研究提供了一种汞离子的无标记检测技术，并且这种开发的系统有可能适用于检测化学物质和生物分子。
