ブックタイトル高分子　POLYMERS　62巻12月号

概要

高分子　POLYMERS　62巻12月号

高分子科学最近の進歩Front-Line Polymer ScienceSmart Photonic Crystal Hydrogels forBiosensing ApplicationsYe Baofen 1,2 , Tian Tian 1 , Lu Jie 1 , Cheng Yao 1 ,Zhao Yuanjin 1,3＊, and Gu Zhongze 1,3＊＊1 State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096, China2 Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009, China3 Laboratory of Environment and Biosafety Research Institute of Southeast University in Suzhou, Suzhou, 215123, China*yjzhao@seu.edu.cn **gu@seu.edu.cn1．IntroductionUnprecedented growth in the development ofbiology and pathology has resulted in the increasingimportance of biosensors by which to understandbiology and medicine at the molecular level. Duringthe past few years, a host of biosensors have beendeveloped, improving their sensitivity and selectivity,simplifying their construction, and potentially loweringthe cost of biological measurements. In biosensorresearch, signal transduction materials have gainedimportance in the construction of the sensor devices,because they ultimately determine many features ofthe biosensors. Responsive hydrogels have been usedas signal transduction materials for the past severaldecades. Changes in the surrounding aqueous solutioncan cause conformation transitions of the gel polymerchains, which transduce to volumetric changes of thehydrogel material and may change the properties ofthe materials, including refractive index, permeabilityand elastic modulus. 1）These changes as a result ofstimulus signal transduction may then be recorded asthe sensing of specific targets.Recent advances in nanotechnology have led to anincreased interest in the construction of polymer hydrogelswith functional nanostructures, for example, the spatiallyordered lattice structures of photonic crystals（PhCs）.Because of their periodic arrangement, a remarkableproperty known as the photonic band gap（PBG）appears in polymer hydrogels. Interactions betweenthe analyte and stimulus-responsive polymers in thehydrogels may result in physicochemical changes of thematerials, including their refractive index, diffractingplane spacing, or both. These structural changes ofthe PhC hydrogels may be observed directly from achange in color or as a shift in their Bragg diffractionpeaks. This feature of PhC hydrogels makes them anideal colorimetric sensor for practical applications.In this review, we present recent research concerningthe development of responsive hydrogel materialsfor biosensor applications. We focus on studies ofPhC hydrogels. Combination of PhCs with responsivehydrogel materials has imparted them with manynew features. To describe these advantages, examplesof the sensing of various types of analytes by PhChydrogels will be presented. Finally, we will present anoutlook for the future development of these remarkablehydrogel materials. We believe that this review willpromote multidisciplinary communication.2．Responsive hydrogelsHydrogels are elastic networks of polymers thatcan take up a certain amount of water in theirinterstitial space. Thus, from a physical point ofview, every type of hydrogel can respond to stress.For example, the volume of hydrogels will shrinkunder pressure and will recover once the pressureis removed. Generally, hydrogels that are stressresponsive alone are not specific network compositions,and hydrogels responsive to other physical（e.g.,temperature, light, electric field）or chemical（e.g., pH,solvent）environments tend to have specific networkcompositions（as summarized in Table 1）.Table 1 Overview of various functional hydrogel polymersType of stimulusPolymerRef.TemperaturePoly(N-isopropyl acrylamide) PNIPAAmPoly(N,N-diethylacrylamide) PDEAAmPoly(vinyl methyl ether) PVMEPoly(N-vinyl caprolactam) PNVCHydroxypropylcellulose HPCPoly(ethylene oxide) PEOPoly(propylene oxide) PPOPoly(tetramethylene glycol) PTMEG2）3）4）5）6）7）8）9）ElectricPoly(diallyldimethylammonium) chloride PDADMACPoly(vinyl alcohol) and hyaluronic acid PVA and HASulfonated polystyrene SPS10）11）12）LightAzobenzeneSpiropyran13）14）PressurePNIPAAmPoly(N-n-propyl acrylamide), Poly(N,N-diethyl acrylamide)15）16）pHPoly(acrylic acid) PAApoly(N,N’-diethylaminoethyl methacrylate) PDEAEMpoly(methacrylic acid) PMApoly(ethylene glycol) PEGPolysaccharides, polypeptides17）18）19）20）21）高分子62巻12月号（2013年）c2013 The Society of Polymer Science, Japan743