Pitruzzella Rosalba, Sequeira Filipa, Cutaia Alessandra, Marzano Chiara, Arcadio Francesco, Novo Catarina Cardoso, Oliveira Ricardo, Pesavento Maria, Zeni Luigi, Alberti Giancarla, Nogueira Rogerio Nunes, Cennamo Nunzio
Department of Engineering, University of Campania Luigi Vanvitelli, Via Roma 29, 81031, Aversa, Italy.
Instituto de Telecomunicações, University of Aveiro, Campus Universitário de Santiago, 3810193 Aveiro, Portugal.
Talanta. 2025 Jul 28;297(Pt A):128647. doi: 10.1016/j.talanta.2025.128647.
In order to monitor analytes in liquid matrices, optical fiber probes in reflection mode can be exploited in several application fields. This work presents a novel sensing approach based on C-shaped waveguides obtained by filling PVC C-shaped channels with microbeads of molecularly imprinted polymers (MIP-microbeads). Specifically, for the first time, MIP microbeads are used as a sensitive core of optical waveguides with several advantages. The MIP microbeads C-shaped waveguide is in contact with a polished plastic optical fiber (POF) at one end to connect the sensitive region with the light source and the detector in a reflection-based scheme via a simple POF-based splitter. As a proof of concept, the MIP-microbeads were prepared using 2-furaldehyde (2-FAL) as the template to compare the results with other optical fiber sensors. Moreover, to highlight the performance improvement of the proposed sensing approach compared to MIP-based configurations, a sensor based on an MIP (MIP-mass sensor) instead of MIP-microbeads has been developed, tested, and compared with the MIP-microbeads sensor and the state-of-the-art. The results obtained via the MIP-microbeads sensor demonstrated the best performance, with an ultra-low detection limit at a pico-nano molar level and an ultra-wide detection concentration range of about four orders of magnitude. Moreover, the proposed optical-chemical sensor probe is small-size (at a micron scale), simple to realize, low-cost, mechanically robust, suitable for installation even in extreme conditions, and can be used in a real scenario where a reflection scheme sensor is required. An experimental test in the food application field is reported.
为了监测液体基质中的分析物，反射模式下的光纤探头可应用于多个领域。本文提出了一种基于C形波导的新型传感方法，该波导通过在PVC C形通道中填充分子印迹聚合物微珠（MIP微珠）获得。具体而言，首次将MIP微珠用作光波导的敏感核心，具有诸多优点。MIP微珠C形波导一端与抛光塑料光纤（POF）接触，通过基于POF的简单分光器，以反射方案将敏感区域与光源和探测器相连。作为概念验证，使用2-糠醛（2-FAL）作为模板制备MIP微珠，以便与其他光纤传感器比较结果。此外，为突出所提传感方法相较于基于MIP的配置的性能提升，已开发、测试了一种基于MIP（MIP质量传感器）而非MIP微珠的传感器，并将其与MIP微珠传感器及现有技术进行比较。通过MIP微珠传感器获得的结果显示出最佳性能，具有皮摩尔至纳摩尔级的超低检测限和约四个数量级的超宽检测浓度范围。此外，所提光化学传感器探头尺寸小（微米级）、易于实现、成本低、机械坚固，即使在极端条件下也适合安装，可用于需要反射方案传感器的实际场景。本文报道了在食品应用领域的实验测试。
