Someya Daichi, Arai Satoshi, Fujie Toshinori, Takeoka Shinji
Department of Life Science and Medical Bioscience, Waseda University TWIns, 2-2 Wakamatsu-cho, Shinjuku-ku Tokyo 162-8480 Japan
PRIME, Japan Agency for Medical Research and Development (AMED) Tokyo 100-0004 Japan.
RSC Adv. 2018 Oct 18;8(62):35651-35657. doi: 10.1039/c8ra06308g. eCollection 2018 Oct 15.
We have developed a sheet-like pH imaging sensor based on a flexible and physically adhesive polymer thin film (referred to as a "pH sensing nanosheet"). The pH sensing nanosheet was composed of two films: one is a pH-sensitive layer-by-layer (LbL) film constructed from fluorescein-conjugated poly(acrylic acid) and poly(allylamine hydrochloride) and the other is a pH-insensitive film made from Nile red-embedded poly(d,l-lactic acid). The pH sensing nanosheet enabled the ratiometric imaging of pH changes in a leaf (500 × 500 μm), namely the apoplastic ion milieu responding to an external NaCl stress. It was successfully mapped out that the alkalization of the leaf apoplast spread from the leaf base to the tip at 20 min after the stimulation and the pH value increased up to approximately pH 6.3 from less than pH 4.5 within 60 min when a 100 mM NaCl aqueous solution was added. The pH sensing nanosheet should be useful for energy metabolic mapping in tissue biology.
我们基于一种柔性且具有物理粘附性的聚合物薄膜（称为“pH 传感纳米片”）开发了一种片状 pH 成像传感器。该 pH 传感纳米片由两层膜组成：一层是由荧光素共轭的聚丙烯酸和聚烯丙基氯化铵构建的 pH 敏感逐层（LbL）膜，另一层是由嵌入尼罗红的聚（d，l-乳酸）制成的 pH 不敏感膜。该 pH 传感纳米片能够对叶片（500×500μm）中的 pH 变化进行比率成像，即对响应外部 NaCl 胁迫的质外体离子环境进行成像。成功绘制出在刺激后 20 分钟时，叶片质外体的碱化从叶基部扩散到叶尖，并且当加入 100 mM NaCl 水溶液时，在 60 分钟内 pH 值从小于 4.5 增加到约 6.3。该 pH 传感纳米片在组织生物学中的能量代谢图谱绘制方面应该是有用的。
