Microwave spectroscopy has been identified as a novel and inexpensive method for the monitoring of water pollutants. Integrating microwave sensors with developed coatings is a novel strategy to make the sensing system more specific for a target contaminant. This study describes the determination of copper and zinc concentration in water in both laboratory-prepared and acquired mine water samples from two abandoned mining areas in Wales, UK. Uncoated sensors immersed in samples spiked with 1.25 mg/L concentrations of copper and zinc, using the standard addition method, were able to quantify the concentration at 0.44 GHz with a strong linear correlation (R² = 0.99) for the reflection coefficient magnitude (|S₁₁|). Functionalised microwave sensors with l-cysteine, chitosan and bismuth zinc cobalt oxide-based coatings have shown improvement in the sensing performance. Specifically, the linear correlation at 0.91–1.00 GHz between |S₁₁| and a polluted water sample spiked with Cu showed a higher (R² = 0.98), sensitivity (1.65 ΔdB/mg/L) and quality factor (135) compared with uncoated sensors (R² = 0.88, sensitivity of 0.82 ΔdB/mg/L and Q-factor 30.7). A Lorentzian peak fitting function was applied for performing advanced multiple peak analysis and identifying the changes in the resonant frequency peaks which are related to the change in metal ion content. This novel sensor platform offers the possibility of in situ monitoring of toxic metal concentrations in mining-impacted water, and multiple peak features, such as area, full width half maximum, centre and height of the peaks, have the possibility to offer higher specificity for similar toxic metals, as between copper and zinc ions.

中文翻译：

---

功能化的微波传感器，用于实时监测采矿影响水中的铜和锌浓度

微波光谱法已经被认为是监测水污染物的一种新颖且廉价的方法。将微波传感器与开发的涂层集成在一起是一种新颖的策略，可以使传感系统对目标污染物的特异性更高。这项研究描述了英国威尔士两个废弃矿区的实验室制备和采集的矿井水样品中水中铜和锌浓度的测定。未涂覆的传感器浸没在铜和锌的1.25毫克/升的浓度掺入的样品，使用标准添加法，能够在0.44千兆赫具有较强的线性相关系数（量化浓度- [R ² 为反射系数大小= 0.99）（| S ₁₁ |）。具有l功能的微波传感器-基于半胱氨​​酸，壳聚糖和铋锌钴氧化物的涂层已显示出传感性能的改善。具体来说，| S ₁₁ |之间的线性相关在0.91–1.00 GHz 。 与未镀膜的传感器（R ²）相比，掺有铜的污水样品具有更高的（R ² = 0.98），灵敏度（1.65ΔdB/ mg / L）和品质因数（135）。 = 0.88，灵敏度为0.82ΔdB/ mg / L，Q因子为30.7）。应用洛伦兹峰拟合函数进行高级多峰分析，并确定与金属离子含量变化有关的共振频率峰变化。这种新颖的传感器平台提供了就地监测受采矿影响的水中有毒金属浓度的可能性，并且多个峰特征（例如面积，峰的半峰全宽，峰的中心和高度）有可能提供更高的特异性铜和锌离子之间的类似有毒金属。