Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia.
Department of Laboratory Medicine, Faculty of Applied Biomedical Sciences, Al-Baha University, Saudi Arabia.
Int J Biol Macromol. 2021 Jul 1;182:2037-2047. doi: 10.1016/j.ijbiomac.2021.05.201. Epub 2021 Jun 2.
Novel sponge-like biochromic swab was developed via immobilization of natural anthocyanin (Cy) biomolecular probe into microporous cellulose aerogel. The current biosensor is characterized with simple preparation, environmentally-friendly, biocompatibility, biodegradability, flexibility, portability and reversibility. This biochromic sponge-like aerogel detector displayed a color change from pink to green-yellow in response to the biochemical changes occurs to sweat. This could be ascribed to intramolecular charge transfer occurs to the molecular system of Cy. Thus, the anthocyanin probe displayed colorimetric variations in UV-Vis absorption spectra via a blue shifting from 620 to 529 nm when raising the pH value of the prepared mimic sweat solution. Natural pH sensitive anthocyanin spectroscopic probe was extracted from red-cabbage plant, characterized by HPLC, and encapsulated into microporous cellulose. The microporous sponge-like cellulose swab was prepared by activating wood pulp utilizing phosphoric acid, and then subjected to freeze-drying. This anthocyanin probe is highly soluble in water. Thus, it was encapsulated as a direct dye into cellulose substrate during the freeze-drying process. To allow a better fixation of this water-soluble anthocyanin probe to the cellulose substrate, potash alum was added to the freeze-dried mixture to act as a fixing agent or mordant (M) generating Cy/M coordination complex. The produced Cy/M nanoparticles (NPs) were explored by transmission electron microscopy (TEM). The morphological features of the generated aerogels were investigated by scan electron microscope (SEM), energy-dispersive X-ray (EDX) spectra, and Fourier-transform infrared spectra (FT-IR). The cytotoxicity of the prepared aerogel-based biosensor was also evaluated. The naked-eye colorimetric changes were studied by exploring color strength, UV-Vis spectra and CIE Lab colorimetric coordinates.
新型海绵状生物变色拭子通过将天然花色苷（Cy）生物分子探针固定在微孔纤维素气凝胶中开发而成。当前的生物传感器具有制备简单、环保、生物相容性、可生物降解性、柔韧性、便携性和可逆性等特点。这种生物变色海绵状气凝胶探测器在响应汗液发生的生化变化时，颜色从粉红色变为绿黄色。这可以归因于花色苷分子系统发生的分子内电荷转移。因此，花色苷探针在模拟汗液溶液的 pH 值升高时，在 UV-Vis 吸收光谱中通过从 620nm 蓝移至 529nm 显示出比色变化。从紫甘蓝植物中提取了天然 pH 敏感花色苷光谱探针，通过 HPLC 进行了表征，并封装到微孔纤维素中。通过使用磷酸活化木浆制备微孔海绵状纤维素拭子，然后进行冷冻干燥。这种花色苷探针在水中高度溶解。因此，它在冷冻干燥过程中被封装为直接染料进入纤维素基质。为了使这种水溶性花色苷探针更好地固定在纤维素基质上，向冷冻干燥混合物中添加钾明矾作为固定剂或媒染剂（M），生成 Cy/M 配位配合物。通过透射电子显微镜（TEM）探索了生成的 Cy/M 纳米颗粒（NPs）。通过扫描电子显微镜（SEM）、能量色散 X 射线（EDX）光谱和傅里叶变换红外光谱（FT-IR）研究了生成气凝胶的形态特征。还评估了基于制备的气凝胶的生物传感器的细胞毒性。通过探索颜色强度、UV-Vis 光谱和 CIE Lab 比色坐标研究了裸眼比色变化。
