Functionalized hydrogel-based colorimetric sensor for Cu2+ detection
With the expansion of industrial activities, monitoring Cu ^2+ ions, i.e., highly toxic and bioaccumulative contaminants in water sources, has become a critical environmental concern. However, current plasmonic nanoparticles colorimetric sensors for Cu ^2+ detection show several limitations, includi...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
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| Series: | Materials Research Express |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/2053-1591/adee83 |
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| Summary: | With the expansion of industrial activities, monitoring Cu ^2+ ions, i.e., highly toxic and bioaccumulative contaminants in water sources, has become a critical environmental concern. However, current plasmonic nanoparticles colorimetric sensors for Cu ^2+ detection show several limitations, including nanoparticle stability, batch-to-batch reproducibility, and slow response times. To address this, we developed a facile and highly sensitive colorimetric sensor based on a hydrogel matrix functionalized with L-cysteine and HAuCl _4 . This approach utilizes a redox reaction between HAuCl _4 and L-cysteine to synthesize gold nanoparticles (AuNPs) directly in the hydrogel. The thiol groups of L-cysteine strongly chemisorb onto the AuNPs surface and form complexes with Cu ^2+ , acting as cross-linkers between the functionalized nanoparticles. These interactions induce agglomeration of AuNPs, resulting in a distinct color change in the hydrogel. The optimal sensor composition consists of 0.75 wt % agar, 0.15 mM L-cysteine, and 1 mM HAuCl _4 , with Cu ^2+ detection at a pH of 4. The sensor exhibits high selectivity, with minimal interference from other metal ions, and achieves a detection limit of 10 μM Cu ^2+ . This functionalized hydrogel matrix sensor highlights a promising potential for environmental safety applications. |
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| ISSN: | 2053-1591 |