苏州大学胡亮团队研制了利用可逆X射线诱导聚N-异丙基丙烯酰胺微凝胶化学变化的干涉仪。相关研究成果发表在2024年11月4日出版的《中国高分子科学杂志》。

光子材料对光有反应，由于其具有可调节结构颜色的能力而引起了人们的兴趣。通常，光的目标是紫外、可见或近红外光谱。

该项研究中，研究人员设计出能够可逆地响应X射线的微凝胶基光子材料。为了实现这一目标，合成了含偶氮苯（Azo）的聚（N-异丙基丙烯酰胺）（pNIPAm）基微凝胶。随后，在聚甲基丙烯酸甲酯（PMMA）基板的每一侧上施加ZnS闪烁体和Cr/Au。随后，将Azo-MG单层沉积在Au表面上，然后沉积额外的Cr/Au层。该过程产生ZnS/PMMA/Cr/Au/Azo-MG/Cr/Au或ZnS/Au-Azo-MG-Au结构。

ZnS/Au-Azo-MG-Au作为一种典型的干涉仪，根据两层Au之间的间距显示出可调的颜色。ZnS闪烁体可以吸收X射线并将其转化为紫外光，从而引发偶氮基团从反式到顺式的转变。因此，这种转变导致Azo MG膨胀。随着Azo-MG膨胀，两个Au层之间的距离增加，导致ZnS/Au-Azo-MG-Au干涉仪的光信号红移约350nm。

值得注意的是，干涉仪的这种X射线响应是可逆的，因为它在黑暗中储存24小时后会恢复到初始状态。为了证明其能力，ZnS/Au-Azo-MG-Au干涉仪在受到X射线刺激时成功释放了一种药物，从而验证了其潜力。基于微凝胶的干涉仪在放化疗、放射生物学和太空致动器中的应用前景广阔。

附：英文原文

Title: Interferometers Utilizing Reversible X-ray-induced Chemical Changes in Poly(N-isopropylacrylamide) Microgels

Author: Ya-Jie Wang, Ping Zhang, Michael J Serpe, Hong Chen, Liang Hu

Issue&Volume: 2024-11-04

Abstract: Photonic materials, which react to light, have garnered interest due to their capability to exhibit adjustable structural colors. Typically, light targets the UV, visible, or near-IR spectrums. In this study, microgel-based photonic materials that are capable of reversibly responding to X-rays have been engineered. To accomplish this, azobenzene (Azo)-containing poly(N-isopropylacrylamide) (pNIPAm)-based microgels are synthesized. Subsequently, ZnS scintillator and Cr/Au are applied on each side of the poly(methyl methacrylate (PMMA) substrate. Subsequently, the Azo MG monolayer is deposited onto the Au surface, followed by the deposition of an additional layer of Cr/Au. This process generates ZnS/PMMA/Cr/Au/Azo MG/Cr/Au or ZnS/Au-Azo MG-Au structure. Functioning as a typical interferometer, ZnS/Au-Azo MG-Au demonstrates tunable colors based on the separation distance between the two Au layers. The ZnS scintillator can absorb and convert X-rays into UV light, initiating the transition of the Azo groups from a trans to a cis state. Consequently, this transition causes the Azo MG to swell. As Azo MG swells, the distance between the two Au layers increases, resulting in a red-shift of approximately 350 nm in the optical signal of the ZnS/Au-Azo MG-Au interferometer. Remarkably, this X-ray responsivity of the interferometer is reversible, as it returns to its initial state after being stored in the dark for 24 h. To demonstrate its capabilities, the ZnS/Au-Azo MG-Au interferometer successfully releases a drug when triggered by X-ray stimulation, thus validating its potential. The microgel-based interferometers hold significant promise for applications in chemoradiotherapy, radiobiology, and actuators in space.

DOI: 10.1007/s10118-024-3223-4

Source: https://www.cjps.org/en/article/doi/10.1007/s10118-024-3223-4/