Giaquinto Martino, Micco Alberto, Aliberti Anna, Bobeico Eugenia, La Ferrara Vera, Ruvo Menotti, Ricciardi Armando, Cusano Andrea
Optoelectronics Group, Department of Engineering, University of Sannio, I-82100 Benevento, Italy.
ENEA, Portici Research Center, P. le E. Fermi 1, Portici, I-80055 Napoli, Italy.
Sensors (Basel). 2018 Apr 6;18(4):1119. doi: 10.3390/s18041119.
Integrating multi-responsive polymers such as microgels onto optical fiber tips, in a controlled fashion, enables unprecedented functionalities to Lab-on-fiber optrodes. The creation of a uniform microgel monolayer with a specific coverage factor is crucial for enhancing the probes responsivity to a pre-defined target parameter. Here we report a reliable fabrication strategy, based on the dip coating technique, for the controlled realization of microgel monolayer onto unconventional substrates, such as the optical fiber tip. The latter was previously covered by a plasmonic nanostructure to make it sensitive to superficial environment changes. Microgels have been prepared using specific Poly(-isopropylacrylamide)-based monomers that enable bulky size changes in response to both temperature and pH variations. The formation of the microgel monolayer is efficiently controlled through the selection of suitable operating pH, temperature and concentration of particle dispersions used during the dipping procedure. The effect of each parameter has been evaluated, and the validity of our procedure is confirmed by means of both morphological and optical characterizations. We demonstrate that when the coverage factor exceeds 90%, the probe responsivity to microgels swelling/collapsing is significantly improved. Our study opens new paradigms for the development of engineered microgels assisted Lab-on-Fiber probes for biochemical applications.
以可控方式将微凝胶等多响应聚合物集成到光纤尖端，可为光纤实验室电极带来前所未有的功能。创建具有特定覆盖因子的均匀微凝胶单层对于提高探针对预定义目标参数的响应性至关重要。在此，我们报告一种基于浸涂技术的可靠制造策略，用于在非常规基板（如光纤尖端）上可控地实现微凝胶单层。光纤尖端先前已被等离子体纳米结构覆盖，使其对表面环境变化敏感。使用特定的基于聚（异丙基丙烯酰胺）的单体制备了微凝胶，这些单体能够响应温度和pH值变化而发生体积变化。通过选择浸涂过程中使用的合适操作pH值、温度和颗粒分散体浓度，可有效控制微凝胶单层的形成。评估了每个参数的影响，并通过形态学和光学表征证实了我们方法的有效性。我们证明，当覆盖因子超过90%时，探针对微凝胶溶胀/收缩的响应性会显著提高。我们的研究为开发用于生化应用的工程微凝胶辅助光纤实验室探针开辟了新的范例。
