Quantitatively Switchable pH-Sensitive Photoluminescence of Carbon Nanodots
| Autor: | Bo Tang, Dai-Wen Pang, Cui Liu, Zongwen Jin, Zhao Jianglin, Mengli Yang, Jiao Hu, Wei Xiaoyuan, Lei Bao, Qing-Ying Luo |
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| Rok vydání: | 2021 |
| Předmět: |
Range (particle radiation)
Photoluminescence Materials science Proton Rational design 02 engineering and technology Conjugated system 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Dissociation (chemistry) 0104 chemical sciences chemistry.chemical_compound Delocalized electron chemistry General Materials Science Carboxylate Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | The Journal of Physical Chemistry Letters. 12:2727-2735 |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/acs.jpclett.1c00287 |
| Popis: | pH sensing plays a key role in the life sciences as well as the environmental, industrial, and agricultural fields. Carbon nanodots (C-dots) with small size, low toxicity, and excellent stability hold great potential in pH sensing as nanoprobes due to their intrinsic pH-sensitive photoluminescence (PL). Nonetheless, the undesirable sensitivity and response range of C-dot PL toward pH cannot meet the requirements of practical applications, and the unclear pH-sensitive PL mechanism makes it difficult to control their pH sensitivity. Herein, the quantitative correlation of pH-sensitive PL with specific surface structures of C-dots is uncovered for the first time, to our best knowledge. The association of carboxylate and H+ increases the ratio of nonradiation to radiation decay of C-dots through excited-state proton transfer, resulting in the decrease of PL intensity. Meanwhile, the dissociation of α-H in β-dicarbonyl forming enolate increases the extent of delocalization of the C-dots conjugated system, which induces the PL broadening to the red region and a decreasing intensity. Based on the understanding of the pH-sensitive PL mechanism, the pH-sensitive PL of C-dots can be switched by quantitative modulation of carboxyl and β-dicarbonyl groups to achieve a desirable pH response range with high sensitivity. This work contributes to a better understanding of the pH-sensitive PL of C-dots and therefore presents an effective strategy for controllably tuning their pH sensitivity, facilitating the rational design of C-dot-based pH sensors. |
| Databáze: | OpenAIRE |
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