The study presented herein investigated an easy preparation, high performance, wavelength-modulated LSPR optical fiber chemosensor coated by gold nanospheres(AuNS) for Hg²⁺ detection based on thymine-Hg²⁺-thymine base pair mismatches and the coupled plasmonic resonance effect.Utilizing electrostatic self-assembly method, the high density and dispersivity monolayer AuNS coated LSPR fiber sensor had the near field refractive index sensitivity up to 2016 nm/RIU. The single-strand probe DNA served as a binding element for free AuNS labelled-target DNA conjugates was attached to the monolayer AuNS by Au-S bond. In the present of Hg²⁺, the coupled plasmonic resonance band between monolayer AuNS and free AuNS was produced by thymine-Hg²⁺-thymine structure and leaded to red-shift of LSPR peak. Under the optimal conditions, the enlarged red-shift in peak of LSPR spectroscopy was linearly with the concentration of Hg²⁺ in the range from 1.0 × 10⁻⁹ to 5.0 × 10⁻⁸ M with the coefficient of 0.976. The limit of detection was 0.7 nM(S/N = 3). The specificity of the sensor was proved high by evaluating the response to other heavy metal ions. The proposed fiber sensor provided a label-free, miniature, low-cost approach for the Hg²⁺ detection and had potential in real environmental evaluations.

本文提出的研究研究了一种易于制备的高性能波长调制LSPR光纤化学传感器，该传感器由金纳米球（AuNS）包覆，用于基于胸腺嘧啶-Hg 2 ^+-胸腺嘧啶碱基对的错配和耦合的等离子体共振效应进行Hg ²⁺检测。利用静电自组装方法，高密度和分散性的单层AuNS涂层LSPR光纤传感器的近场折射率灵敏度高达2016 nm / RIU。用作游离AuNS标记的靶DNA缀合物的结合元件的单链探针DNA通过Au-S键连接至单层AuNS。在Hg ²⁺的存在下，胸腺嘧啶-Hg ²⁺产生了单层AuNS与游离AuNS之间的耦合等离子体共振带。胸腺嘧啶的结构并导致LSPR峰的红移。在最佳条件下，LSPR光谱的峰红移与Hg ²⁺的浓度在1.0×10 ^-9至5.0×10 ^-8 M范围内呈线性关系，系数为0.976。检测限为0.7 nM（S / N = 3）。通过评估对其他重金属离子的响应，证明了该传感器的高特异性。所提出的光纤传感器为Hg ^2+的检测提供了一种无标签，微型，低成本的方法，并且在实际的环境评估中具有潜力。