The synthesis and pH-sensing property of a novel phenalenone-based compound, 9-(4-hydroxyphenylamino)-1-oxo-phenalenone (HPAP), is reported. The newly synthesized compound is capable of functioning as a pH sensor in the region of pH 7 to 12. The sensor can be used as a colorimetric indicator in the transition from pH 10 to pH 11. The sensor is able to function in four detectable channels. All four channels (UV, emission, colorimetric/visible and photoluminescence) have been shown to be reversible, thus implying the reuse of this single-molecule sensor and indicator for several experiments. Mechanistic investigations have been performed by UV, NMR and DFT studies which indicate that a photoinduced electron transfer (PET) based mechanism could be operative. Straightforward and cost-effective application of the sensor in thin-layer chromatography has also been established.

中文翻译：

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基于苯甲酮的pH传感器的设计，合成和光化学特性：四个可检测通道中的可切换pH传感。

报道了一种新型的基于苯丙烯酮的化合物9-（4-羟苯基氨基）-1-氧代-苯丙烯酮（HPAP）的合成和pH敏感特性。新合成的化合物可以在pH 7到12的范围内充当pH传感器。该传感器可以用作从pH 10到pH 11的比色指示剂。该传感器可以在四个可检测通道中发挥作用。所有四个通道（紫外线，发射，比色/可见光和光致发光）均显示为可逆的，因此暗示该单分子传感器和指示剂可重复用于多个实验。通过UV，NMR和DFT研究进行了机理研究，这些研究表明基于光致电子转移（PET）的机理可能有效。