希薄溶液中で効率的な発光を示すポリ-L-アスパラギン酸系非従来型発光生体高分子によるアルミニウムイオン検出
Nonconventional luminescent macromolecules typically show weak emission in dilute solutions, restricting their practical use. This study proposed a molecular design strategy combining hydrophobic rigid segments, hydrophilic flexible chains, and inter/intramolecular hydrogen bonding to enable effective luminescence under dilute conditions. Poly-L-aspartic acid (PASA) was synthesized as a proof-of-concept, achieving a fluorescence quantum yield of 4.6% at 0.8 mg/mL. Fluorescence intensity rose with increasing concentration, consistent with a clustering-triggered emission mechanism. Upon addition of aluminum ions (Al³⁺), the fluorescence signal was markedly amplified through an Al³⁺ recognition effect, yielding a detection limit of 1.71 × 10 mol/L that satisfies WHO food-safety standards. Solid-state PASA samples additionally displayed room-temperature phosphorescence.
Clustering-triggered emission arises from cooperative interactions among hydrophobic rigid chains, hydrophilic flexible segments, and hydrogen bonds within PASA. Coordination between Al³⁺ and the polymer further amplifies fluorescence intensity through an ion-recognition effect.
This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).
See also:
https://h2-papers.org/en/papers/36455817