Dataset Information

Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters.

ABSTRACT: 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@TiO2 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 TiO2 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-1 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-1 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@TiO2 dipstick provides a single-step sample preparation and preconcentration approach that combines sustainability with high analytical sensitivity and accuracy.

SUBMITTER: Stock V

PROVIDER: S-EPMC7921970 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters.

Stock Vivian V Mutschler Anna A Lindén Mika M Leopold Kerstin K

Nanomaterials (Basel, Switzerland) 20210218 2

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 prec ...[more]

PMID: 33670486

Similar Datasets

Project description:Trace-level detection of mercury in waters is connected with several complications including complex multistep analysis routines, applying additional, harmful reagents increasing the risk of contamination, and the need for expensive analysis equipment. Here, we present a straightforward reagent-free approach for mercury trace determination using a novel thin film sampling stick for passive sampling based on gold nanoparticles. The nanoparticles supported on a silicon wafer and further covered with a thin layer of mesoporous silica. The mesoporous silica layer is acting as a protection layer preventing gold desorption upon exposure to water. The gold nanoparticles are created by thermal treatment of a homogenous gold layer on silicon wafer prepared by vacuum evaporation. This gold-covered substrate is subsequently covered by a layer of mesoporous silica through dip-coating. Dissolved mercury ions are extracted from a water sample, e.g., river water, by incorporation into the gold matrix in a diffusion-controlled manner. Thus, the amount of mercury accumulated during sampling depends on the mercury concentration of the water sample, the accumulation time, as well as the size of the substrate. Therefore, the experimental conditions can be chosen to fit any given mercury concentration level without loss of sensitivity. Determination of the mercury amount collected on the stick is performed after thermal desorption of mercury in the gas phase using atomic fluorescence spectrometry. Furthermore, the substrates can be re-used several tens of times without any loss of performance, and the batch-to-batch variations are minimal. Therefore, the nanogold-mesoporous silica sampling substrates allow for highly sensitive, simple, and reagent-free determination of mercury trace concentrations in waters, which should also be applicable for on-site analysis. Successful validation of the method was shown by measurement of mercury concentration in the certified reference material ORMS-5, a river water.

Project description:ObjectiveTitanium dioxide nanoparticles (TiO2) nanoparticles have been widely explored in the prevention of cancer risk. Due to the difficult solubility of TiO2 nanoparticles, it is essential to synthesize new surfactants to increase its bioavailability and anti-tumor activity and reduce its cytotoxicity. Furthermore, oxidative and inflammation are closely associated with the osteosarcoma risk. Chitosan has biocompatibility, antioxidant and anti-inflammatory properties. The effects of chitosan-coated TiO2-embedded paclitaxel nanoparticles on an osteosarcoma model were explored.MethodsAn osteosarcoma model was established and chitosan-coated TiO2-embedded paclitaxel nanoparticles were prepared using a freeze-drying strategy. The morphological characteristics of nanoparticles were observed using scanning electron microscopy (SEM). The physicochemical properties of nanoparticle were evaluated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The cytotoxicity was tested by using human osteoblast cells hFob1.19 and osteosarcoma cells 143B. Osteosarcoma mice were treated with PBS buffer, paclitaxel, TiO2-embedded paclitaxel and chitosan-coated TiO2-embedded paclitaxel nanoparticles. The biomarkers of oxidative-inflammatory status, anti-tumor activities and survival rates of the model were measured.ResultsXRD analysis showed that the peaks of chitosan/TiO2 (anatase) were consistent with those of crystalline TiO2 and broad phase of chitosan. The FTIR spectrum indicated the relevant functional groups in TiO2. Chitosan-coated TiO2-embedded paclitaxel nanoparticles had good biocompatibility and improve antioxidant and anti-inflammatory properties in the osteosarcoma model. Chitosan-coated TiO2-embedded paclitaxel nanoparticles was less toxic to the cells hFob1.19 and more toxic to the cells 143B than TiO2-embedded paclitaxel nanoparticles. Chitosan-coated TiO2-embedded paclitaxel nanoparticles showed significant antitumor activity and increased the survival rate of the osteosarcoma model (P < 0.05).ConclusionsChitosan improved anti-tumor potential of TiO2-embedded paclitaxel nanoparticles in the prevention of osteosarcoma.

Dataset Information

Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters.

Publications

Photoactive Titanium Dioxide Films with Embedded Gold Nanoparticles for Quantitative Determination of Mercury Traces in Humic Matter-Containing Freshwaters.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets