Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters
Mercury detection in humic matter-containing natural waters is often associated with environmental harmful substances for sample preparation. Herein we report an approach based on photoactive titanium dioxide films with embedded gold nanoparticles (AuNP@TiO<sub>2</sub> dipstick) for chem...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-02-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/11/2/512 |
| _version_ | 1797396168119943168 |
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| author | Vivian Stock Anna Mutschler Mika Lindén Kerstin Leopold |
| author_facet | Vivian Stock Anna Mutschler Mika Lindén Kerstin Leopold |
| author_sort | Vivian Stock |
| collection | DOAJ |
| description | Mercury detection in humic matter-containing natural waters is often associated with environmental harmful substances for sample preparation. Herein we report an approach based on photoactive titanium dioxide films with embedded gold nanoparticles (AuNP@TiO<sub>2</sub> dipstick) for chemical-free sample preparation and mercury preconcentration. For this purpose, AuNPs are immobilized onto a silicon wafer and further covered with a thin photoactive titanium dioxide layer. The AuNPs allow the preconcentration of Hg traces via amalgamation, while TiO<sub>2</sub> acts as a protective layer and, at the same time, as a photocatalyst for UV-C radiation-based sample pretreatment. Humic matter, often present in natural waters, forms stabile complexes with Hg and so hinders its preconcentration prior to detection, causing a minor recovery. This problem is solved here by irradiation during Hg preconcentration onto the photoactive dipstick, resulting in a limit of detection as low as 0.137 ng L<sup>−1</sup> using atomic fluorescence spectrometry (AFS). A 5 min preconcentration step is sufficient to obtain successful recovery of Hg traces from waters with up to 10 mg L<sup>−1</sup> DOC. The feasibility of the approach was demonstrated by the determination of Hg traces in Danube river water. The results show no significant differences in comparison with standard cold vapor-atomic fluorescence spectrometry (CV-AFS) measurements of the same sample. Hence, this new AuNP@TiO<sub>2</sub> dipstick provides a single-step sample preparation and preconcentration approach that combines sustainability with high analytical sensitivity and accuracy. |
| first_indexed | 2024-03-09T00:47:22Z |
| format | Article |
| id | doaj.art-27a6208fee1740d58a775e3b0f7ad324 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-09T00:47:22Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-27a6208fee1740d58a775e3b0f7ad3242023-12-11T17:27:10ZengMDPI AGNanomaterials2079-49912021-02-0111251210.3390/nano11020512Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing FreshwatersVivian Stock0Anna Mutschler1Mika Lindén2Kerstin Leopold3Department of Analytical and Bioanalytical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, GermanyDepartment of Inorganic Chemistry II, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, GermanyDepartment of Inorganic Chemistry II, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, GermanyDepartment of Analytical and Bioanalytical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, GermanyMercury detection in humic matter-containing natural waters is often associated with environmental harmful substances for sample preparation. Herein we report an approach based on photoactive titanium dioxide films with embedded gold nanoparticles (AuNP@TiO<sub>2</sub> dipstick) for chemical-free sample preparation and mercury preconcentration. For this purpose, AuNPs are immobilized onto a silicon wafer and further covered with a thin photoactive titanium dioxide layer. The AuNPs allow the preconcentration of Hg traces via amalgamation, while TiO<sub>2</sub> acts as a protective layer and, at the same time, as a photocatalyst for UV-C radiation-based sample pretreatment. Humic matter, often present in natural waters, forms stabile complexes with Hg and so hinders its preconcentration prior to detection, causing a minor recovery. This problem is solved here by irradiation during Hg preconcentration onto the photoactive dipstick, resulting in a limit of detection as low as 0.137 ng L<sup>−1</sup> using atomic fluorescence spectrometry (AFS). A 5 min preconcentration step is sufficient to obtain successful recovery of Hg traces from waters with up to 10 mg L<sup>−1</sup> DOC. The feasibility of the approach was demonstrated by the determination of Hg traces in Danube river water. The results show no significant differences in comparison with standard cold vapor-atomic fluorescence spectrometry (CV-AFS) measurements of the same sample. Hence, this new AuNP@TiO<sub>2</sub> dipstick provides a single-step sample preparation and preconcentration approach that combines sustainability with high analytical sensitivity and accuracy.https://www.mdpi.com/2079-4991/11/2/512mesoporous titanium dioxide filmsgold nanoparticlessampling stickmercury trace analysisfreshwaterhumic matter |
| spellingShingle | Vivian Stock Anna Mutschler Mika Lindén Kerstin Leopold Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters Nanomaterials mesoporous titanium dioxide films gold nanoparticles sampling stick mercury trace analysis freshwater humic matter |
| title | Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters |
| title_full | Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters |
| title_fullStr | Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters |
| title_full_unstemmed | Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters |
| title_short | Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters |
| title_sort | photoactive titanium dioxide films with embedded gold nanoparticles for quantitative determination of mercury traces in humic matter containing freshwaters |
| topic | mesoporous titanium dioxide films gold nanoparticles sampling stick mercury trace analysis freshwater humic matter |
| url | https://www.mdpi.com/2079-4991/11/2/512 |
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