Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions
Stimuli-responsive polymeric nanoparticles (NPs) exhibit reversible changes in the dispersion or aggregation state in response to external stimuli. In this context, we designed and synthesized core-shell NPs with threonine-containing weak polyelectrolyte shells and fluorescent cross-linked cores, wh...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-03-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/14/7/1362 |
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| author | Keita Kataoka Kazuhiro Nakabayashi Chen-Tsyr Lo Hideharu Mori |
| author_facet | Keita Kataoka Kazuhiro Nakabayashi Chen-Tsyr Lo Hideharu Mori |
| author_sort | Keita Kataoka |
| collection | DOAJ |
| description | Stimuli-responsive polymeric nanoparticles (NPs) exhibit reversible changes in the dispersion or aggregation state in response to external stimuli. In this context, we designed and synthesized core-shell NPs with threonine-containing weak polyelectrolyte shells and fluorescent cross-linked cores, which are applicable for the detection of pH changes and amine compounds in aqueous solution. Stable and uniform NP(dTh) and NP(Fl), consisting of fluorescent symmetric diphenyl dithiophene (dTh) and diphenyl fluorene (Fl) cross-linked cores, were prepared by site-selective Suzuki coupling reactions in self-assembled block copolymer. NP(Fl) with the Fl unit in the core showed a high fluorescence intensity in different solvents, which is regarded as an aggregation-induced emission-type NP showing strong emission in aggregated states in the cross-linked core. Unimodal NPs were observed in water at different pH values, and the diameter of NP(Fl) changed from 122 (pH = 2) to 220 nm (pH = 11). Furthermore, pH-dependent changes of the fluorescence peak positions and intensities were detected, which may be due to the core aggregation derived from the deprotonation of the threonine-based shell fragment. Specific interactions between the threonine-based shell of NP(Fl) and amine compounds (triethylamine and <i>p</i>-phenylenediamine) resulted in fluorescence quenching, suggesting the feasibility of fluorescent amine detection. |
| first_indexed | 2024-03-09T11:31:06Z |
| format | Article |
| id | doaj.art-fc5353cf7aef4f139a8819f06f66ea47 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T11:31:06Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-fc5353cf7aef4f139a8819f06f66ea472023-11-30T23:53:25ZengMDPI AGPolymers2073-43602022-03-01147136210.3390/polym14071362Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous SolutionsKeita Kataoka0Kazuhiro Nakabayashi1Chen-Tsyr Lo2Hideharu Mori3Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, JapanGraduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, JapanGraduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, JapanGraduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, JapanStimuli-responsive polymeric nanoparticles (NPs) exhibit reversible changes in the dispersion or aggregation state in response to external stimuli. In this context, we designed and synthesized core-shell NPs with threonine-containing weak polyelectrolyte shells and fluorescent cross-linked cores, which are applicable for the detection of pH changes and amine compounds in aqueous solution. Stable and uniform NP(dTh) and NP(Fl), consisting of fluorescent symmetric diphenyl dithiophene (dTh) and diphenyl fluorene (Fl) cross-linked cores, were prepared by site-selective Suzuki coupling reactions in self-assembled block copolymer. NP(Fl) with the Fl unit in the core showed a high fluorescence intensity in different solvents, which is regarded as an aggregation-induced emission-type NP showing strong emission in aggregated states in the cross-linked core. Unimodal NPs were observed in water at different pH values, and the diameter of NP(Fl) changed from 122 (pH = 2) to 220 nm (pH = 11). Furthermore, pH-dependent changes of the fluorescence peak positions and intensities were detected, which may be due to the core aggregation derived from the deprotonation of the threonine-based shell fragment. Specific interactions between the threonine-based shell of NP(Fl) and amine compounds (triethylamine and <i>p</i>-phenylenediamine) resulted in fluorescence quenching, suggesting the feasibility of fluorescent amine detection.https://www.mdpi.com/2073-4360/14/7/1362core-cross-linked nanoparticlesfluorescent amine detectionaggregation-induced emissionpH-responsive nanoparticlesself-assembled block copolymer |
| spellingShingle | Keita Kataoka Kazuhiro Nakabayashi Chen-Tsyr Lo Hideharu Mori Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions Polymers core-cross-linked nanoparticles fluorescent amine detection aggregation-induced emission pH-responsive nanoparticles self-assembled block copolymer |
| title | Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions |
| title_full | Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions |
| title_fullStr | Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions |
| title_full_unstemmed | Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions |
| title_short | Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions |
| title_sort | threonine based stimuli responsive nanoparticles with aggregation induced emission type fixed cores for detection of amines in aqueous solutions |
| topic | core-cross-linked nanoparticles fluorescent amine detection aggregation-induced emission pH-responsive nanoparticles self-assembled block copolymer |
| url | https://www.mdpi.com/2073-4360/14/7/1362 |
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