In this paper, we propose and demonstrate a high-performance mercury ion sensor with sub-nM detection limit, high selectivity, and strong practicability based on the small molecule of the 4-mercaptopyridine (4-MPY) modified tilted fiber Bragg grating surface plasmon resonance (TFBG-SPR) sensing platform. The TFBG-SPR sensor has a rich mode field distribution and a narrow bandwidth, which can detect the microscopic physical and chemical reactions on the sensor surface with high sensitivity without being disturbed by the external temperature. For the environmental compatibility and highly efficient capture of the toxic mercury ion, 4-MPY is modified on the sensor surface forming a stable (4-MPY)-Hg-(4-MPY) structure due to the specific combination between the nitrogen of the pyridine moiety and the Hg²⁺ via multidentate N-bonding. Moreover, gold nanoparticles (AuNPs) are connected to the sensor surface through the (4-MPY)-Hg-(4-MPY) structure, which could play an important role for signal amplification. Under the optimized conditions, the limit of detection of the sensor for mercury ions detection in the solution is as low as 1.643×10⁻¹⁰ M (0.1643nM), and the detection range is 1×10⁻⁹ M − 1×10⁻⁵ M. At the same time, the mercury ion spiked detection with tap water shows that the sensor has the good selectivity and reliability in actual water samples. We develop a valuable sensing technology for on-time environmental Hg²⁺ detection and in-vivo point of care testing in clinic applications.

在本文中，我们基于4-巯基吡啶（4-MPY）修饰的倾斜光纤布拉格光栅表面等离子体激元的小分子，提出并演示了一种具有亚纳米级检测限，高选择性和强实用性的高性能汞离子传感器。共振（TFBG-SPR）感应平台。TFBG-SPR传感器具有丰富的模式场分布和较窄的带宽，可在不受到外部温度干扰的情况下，以高灵敏度检测传感器表面上的微观物理和化学反应。为确保环境兼容性和高效捕获有毒汞离子，由于传感器中氮之间的特定结合，在传感器表面对4-MPY进行了修饰，形成了稳定的（4-MPY）-Hg-（4-MPY）结构。吡啶部分和Hg ²⁺通过多齿N键 此外，金纳米颗粒（AuNPs）通过（4-MPY）-Hg-（4-MPY）结构连接到传感器表面，这可能对信号放大起重要作用。在优化条件下，检测所述传感器为汞离子在溶液中的检测限为低至1.643×10 ^-10 M（0.1643nM），并且检测范围为1×10 ^-9米- 1×10 ^{- 5} M.与此同时，汞离子掺入用自来水表明，该传感器具有实际水样中的良好的选择性和可靠性检测。我们开发了一种有价值的传感技术，可用于临床应用中的实时环境Hg ²⁺检测和体内即时护理测试。