We present three types of optical ammonia sensors suitable for environmental, bioprocess, and reaction monitoring. A respective fluorescent BF₂-chelated tetraarylazadipyrromethene dye (aza-BODIPYs) is physically entrapped in a polyurethane hydrogel (HydroMed D4) forming an emulsion system with vinyl-terminated polydimethylsiloxane (PDMS). The analyte-sensitive layer is covered by a hydrophobic membrane which excludes hydrophilic substances. Three different protection layers are tested, whereby the Teflon and the hydrophobic PES layers outperform a PDMS/TiO₂ layer. Response times within their dynamic range of 15 s can be achieved, whereas the PDMS/TiO₂-covered sensor requires at least 390 s. The three sensors entail the following concentration areas: first sensor 3 μg L⁻¹–3 mg L⁻¹ (LOD 0.23 μg L⁻¹), second sensor 0.1–30 mg L⁻¹ (LOD 28 μg L⁻¹), and third sensor 3 mg L⁻¹–1 g L⁻¹ (LOD 0.51 mg L⁻¹). Readout is performed with a commercially available phase fluorimeter combined with optical fibers. Dual-lifetime referencing (DLR) is used as referencing method and Egyptian blue acts as an inert reference material. No cross-sensitivity to pH changes can be detected.

我们推出三种类型的光学氨传感器，适用于环境、生物过程和反应监测。相应的荧光BF ₂螯合四芳基氮杂二吡咯亚甲基染料（aza-BODIPYs）被物理捕获在聚氨酯水凝胶（HydroMed D4）中，与乙烯基封端的聚二甲基硅氧烷（PDMS）形成乳液系统。分析物敏感层被疏水膜覆盖，该疏水膜排除了亲水物质。测试了三种不同的保护层，其中特氟龙和疏水性 PES 层的性能优于 PDMS/TiO ₂层。可以实现 15 秒动态范围内的响应时间，而 PDMS/TiO ₂覆盖的传感器需要至少 390 秒。三个传感器需要以下浓度区域：第一个传感器 3 μg L ^-1 –3 mg L ^-1 (LOD 0.23 μg L ^-1 )，第二个传感器 0.1–30 mg L ^-1 (LOD 28 μg L ^-1 )，和第三个传感器 3 mg L ^-1 –1 g L ^-1 (LOD 0.51 mg L ^-1 )。使用与光纤结合的市售相位荧光计进行读出。使用双寿命参考 (DLR) 作为参考方法，埃及蓝作为惰性参考材料。未检测到对 pH 值变化的交叉敏感性。