A U-Shape Fibre-Optic pH Sensor Based on Hydrogen Bonding of Ethyl Cellulose With a Sol-Gel Matrix
A U-Shape Fibre-Optic pH Sensor Based on Hydrogen Bonding of Ethyl Cellulose With a Sol-Gel Matrix
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DOI：
10.1109/jlt.2020.3034563
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发表时间：
2021-03-01
影响因子：
4.7
通讯作者：
Liu, Liangliang
中科院分区：
文献类型：
--
作者：
Tang, Zijuan;Gomez, David;Liu, Liangliang
生物相容性pH传感器的开发在生物医学应用中具有重要意义，特别是对于体内测量，为临床诊断和治疗提供必要的信息，例如慢性伤口和胎儿酸中毒。传统的基于pH指示剂的光学传感器存在染料浸出和光漂白的问题，限制了它们在长期监测中的应用。在这项工作中，提出了一种无染料的光纤pH传感器由一个U形多模光纤涂有一个混合的有机-无机复合膜。该膜通过乙基纤维素与二氧化硅基质以0.0065的最佳乙基纤维素/二氧化硅摩尔比经由弱相互作用的氢键交联而形成。这种键合受氢浓度的影响（即，pH），导致二氧化硅基质中存在的聚合物聚集体的形态变化，从而导致膜的折射率变化。所开发的传感器显示出对pH从4.5到12.5的可逆响应，并且在透射光功率和pH之间表现出线性相关性，传感器和商业探针之间的一致性极限（LoA）为+/-0.2pH。对于临床上重要的pH值范围在6和8之间，LoA为+/-0.1pH。当温度从21摄氏度变化到39摄氏度时，对温度的灵敏度为归因于功率变化的最大解释pH变化为0.12 pH。为了证明生物医学相关性，传感器用于监测人血清的pH值。使用小鼠成纤维细胞进行内部细胞毒性试验，结果表明薄膜无细胞毒性。
Development of a biocompatible pH sensor is of importance in biomedical applications, particularly for in vivo measurement, providing necessary information for clinical diagnosis and treatment such as chronic wounds and foetal acidosis. Traditional pH-indicator based optical sensors have problems of dye-leaching and photobleaching that restrict their uses in long-term monitoring. In this work, a dye-free fibre optic pH sensor is proposed consisting of a U-shape multimode optical fibre coated with a hybrid organic-inorganic composite film. The film is formed by cross-linking ethyl cellulose with a silica matrix at an optimised ethyl cellulose/silica molar ratio of 0.0065 via weakly interacted hydrogen bonding. This bonding is affected by hydrogen concentration (i.e., pH) in a solution resulting in a morphological change of the polymer aggregation presented in the silica matrix leading to refractive index change of the film. The developed sensor shows a reversible response to pH from 4.5 to 12.5 and exhibits linear correlation between transmitted light power and pH with a limit of agreement (LoA) between the sensor and a commercial probe of +/- 0.2 pH. For a clinically important range of pH values between 6 and 8 the LoA is +/- 0.1 pH. The sensor has low cross-sensitivity to temperature as the maximum interpreted pH change attributed to the power change is 0.12 pH when the temperature changes from 21 degrees C to 39 degrees C. To demonstrate biomedical relevance, the sensor is used to monitor pH of human serum. An in-house cytotoxicity assay is conducted with mouse fibroblast cell revealing that the film is not cytotoxic.