基于智能水凝胶的多参数光纤生物传感器

It is very important to detect several substances continuously or simultaneously in many fields such as clinical medicine and environment protection. At present, by using fiber optic biosensor, different sensor heads are needed for the detection of different biosubstances, which has the disadvantages of long detection time, high cost and complicated preparation, etc. Because different biosubstances can be detected only if they are oxidized with the catalysis of different special enzymes, and intelligent hydrogel can "swell" or "deswell" reversibly in different temperature range, in this project, photosensitizer and different enzymes were slectively embeded in intelligent hydrogel to form the sensing materials. When hydrogel "swell", the biosubstance can pass through its grids and react with enzyme, and the detection of biosubstance can be realized. When the hydrogel "shrink", the biosubstance can not enter the hydrogel and the detection will stop. Therefore, by controlling temperature, different substances in the same sample (for example, glucose and cholesterol in blood) can be detected by the sensor at different temperature with one optode and one signal detecting system, and intelligent detection of multiparameters can be realized. By using optic fiber microprocessing technology, the periodical multihole strcture will be prepared to construct the sensor head, which will be beneficial to the immobilization of sensing materials. In this project, the relationship between the structure and properties of the sensing materials will be studied, and the sensing machanism and properties of the fiber optic biosensor will be researched. It is expected that a new way will be explored for the research and application of this kind of sensing materials.

连续（或同时）检测多种物质在临床医学和环保等许多领域都非常重要。目前光纤生物传感器必须采用不同的探头来检测不同生物量，造成费时长、成本高、制备复杂。由于不同待测物必须在不同生物酶作用下催化氧化才能被检测，智能水凝胶在不同的温度范围可发生"溶胀"或"收缩"，并且是可逆的，本项目将光敏剂和不同的酶选择性地包覆在水凝胶中组成传感材料，水凝胶"溶胀"时，待测物可穿过其网格与酶作用，实现对待测物检测，当其"收缩"时，待测物无法进入，检测停止。故可通过控制温度，采用一个光极和一套检测系统，使传感器在不同温度下检测同一样品中的不同物质（如血液中的葡萄糖和胆固醇等），实现多参数"智能化"检测。这将使传感器的制备工艺和信号处理大大简化。采用光纤微加工技术，将传感器探头制成周期性多孔结构，以利于传感材料的固定。研究传感材料结构与性能的关系和传感器的传感机理与性能，为这类传感材料的研究和应用探索一条新路。

在临床医学和环保等许多领域，需要连续（或同时）检测多种物质。目前检测不同生物量只能采用不同探头的光纤生物传感器，存在成本高、费时长、制备复杂等缺点，难以满足实际应用的需要。为此，我们制备了具有可逆“溶胀-收缩”性能的智能水凝胶，并选择性地包覆不同的固定化酶，由此制备温度控制的多参数光纤生物传感器，实现了在不同温度下对多种生物量（葡萄糖、胆固醇）的连续检测, 为这类新型传感器的研究和应用探索了一条新路。. 制备了Fe3O4@SiO2(F)@meso-SiO2的磁性荧光纳米复合粒子及其固定化GOD和固定化COD。制备了水凝胶P(NIPAAm-co-AAm)-磁性纳米粒子固定化GOD复合物以及基于此复合物的温控型光纤葡萄糖传感器，其对葡萄糖的温控检测范围为50–700 mg/dL。制备了基于磁性复合粒子固定化COD的光纤胆固醇传感器，研究了传感器的性能。由此制备了基于上述复合物和磁性复合粒子固定化COD的多参数光纤生物传感器，研究了该传感器的传感机理和性能。通过控制温度，实现了对胆固醇和葡萄糖的连续检测。传感器检测胆固醇的范围：25-250mg/dL，检测葡萄糖的范围：50-700mg/dL。响应时间均为200s，并具有较好的重复性、长期稳定性和抗干扰能力，对实际样品检测的效果较好。. 由于SiO2纳米粒子具有制备简单、稳定性和生物相容性好的优点，智能水凝胶PNIPAAm具有响应快、制备方便的特点，我们制备了基于PNIPAAm-SiO2纳米粒子固定化GOD复合物和SiO2纳米粒子固定化COD的多参数光纤生物传感器，在不同的温度下，实现了对胆固醇和葡萄糖的连续检测。传感器检测胆固醇的范围： 20-180mg/dL（该检测范围有待于拓宽），检测葡萄糖的范围：50-700mg/dL，响应时间均为200s，其重复性、长期稳定性和抗干扰能力均较好，可用于对实际样品的检测。