Flow-Field-Flow Fractionation (Flow-FFF), coupled with online detection systems, is one of the most promising tools available for the analysis and characterization of engineered nanoparticles (ENPs) in complex matrices. In order to demonstrate the applicability of Flow-FFF for the detection, quantification, and characterization of engineered gold nanoparticles (AuNPs), model dispersions were prepared containing AuNPs with diameters of 30 or 100nm, natural nanoparticles (NNPs) extracted from a soil sample, and different concentrations of natural organic matter (NOM), which were then used to investigate interactions between the AuNPs and the NNPs. It could be shown that light scattering detection can be used to evaluate the fractionation performance of the pure NNPs, but not the fractionation performance of the mixed samples that also contained AuNPs because of specific interactions between the AuNPs and the laser light. A combination of detectors (i.e. light absorbance and inductively coupled plasma mass spectrometry (ICP-MS)) was found to be useful for differentiating between heteroaggregation and homoaggregation of the nanoparticles (NPs). The addition of NOM to samples containing 30nm AuNPs stabilized the AuNPs without affecting the NP size distribution. However, fractograms for samples with no added NOM showed a change in the size distribution, suggesting interactions between the AuNPs and NNPs. This interpretation was supported by unchanged light absorption wavelengths for the AuNPs. In contrast, results for samples containing 100nm AuNPs were inconclusive with respect to recovery and size distributions because of problems with the separation system that probably related to the size and high density of these nanoparticles, highlighting the need for extensive method optimization strategies, even for nanoparticles of the same material but different sizes.
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http://dx.doi.org/10.1016/j.chroma.2014.10.093 | DOI Listing |
J Agric Food Chem
January 2025
College of Chemistry and Chemical Engineering, Jishou University, Jishou, Hunan 416000, P. R. China.
Detecting β-lactoglobulin (β-Lg) with high sensitivity and selectivity is an urgent requirement due to nearly 80% of milk anaphylaxis, such as respiratory tract, skin urticaria, and gastrointestinal disorders, being caused by β-Lg. An ultrasensitive β-Lg electrochemical aptasensor utilizing core-satellite gold nanoparticle@silver nanocluster (AuNPs@AgNCs) nanohybrids as electrocatalysts was developed. First, β-Lg aptamer was anchored on gold electrodes and AuNPs to obtain high selectivity.
View Article and Find Full Text PDFChem Asian J
January 2025
Chulalongkorn University, Chemistry, THAILAND.
This research focuses on the selective detection of Hg2+ ions using hybrid nanosensors composed of rhodamine building blocks linked to polyamine units of varying chain lengths to produce Rho1-Rho4, which were subsequently conjugated with thioctic acid (RT1-RT4) and attached to the surface of gold nanoparticles to create hybrid nanosensors (GRT1-GRT4) designed for detecting heavy metals. The chemical structures, purity, morphology, and chemical composition were characterized through XRD, NMR, TEM, ATR-FTIR, and mass spectrometry. These hybrid nanosensors demonstrated excellent selectivity and sensitivity in colorimetric and fluorescence responses towards Hg2+, outperforming other metal ions.
View Article and Find Full Text PDFAnalyst
January 2025
College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China.
A novel electrochemical microsensor was constructed on a traditional acupuncture needle (AN) and used to monitor a biomarker of the SARS-CoV-2-N protein. The reversible interaction of the borate bond between the -diol in this glycoprotein and the phenylboronic acid in 4-mercaptophenylboronic acid (4-MPBA) was accomplished. This interaction was applied to anchor the SARS-CoV-2-N protein onto 4-MPBA, which was covalently self-assemblied onto electrodeposited AuNPs by the S-Au bond.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Department of Chemical Sciences, University of Johannesburg, Doornfontein, Johannesburg, South Africa.
Point of Care (POC) diagnosis provides an effective approach for controlling and managing Neglected Tropical Diseases (NTDs). Electrochemical biosensors are well-suited for molecular diagnostics due to their high sensitivity, cost-effectiveness, and ease of integration into POC devices. Schistosomiasis is a prominent NTD highly prevalent in Africa, Asia, and Latin America, with significant socioeconomic implications such as discrimination, reduced work capacity, or mortality, perpetuating the cycle of poverty in affected regions worldwide.
View Article and Find Full Text PDFTalanta
January 2025
Department of Chemistry Education, Farhangian University, P.O. Box 14665-889, Tehran, Iran. Electronic address:
Although the dosage controlling of tramadol (TRA) as a banned deadly drug in human biofluids is medicolegally important a biocompatible method for its high-selective detection with fewer false interferences has been scarcely reported. Herein, a new impedimetric aptasensor is introduced by utilizing the aptamer (Apt) sequence with high affinity to TRA for the first time to non-invasively measure it. An oriented nanolayer of Au nanoparticles (AuNPs) is easily formed on the surface by the electrodeposition technique to high-densely load the Apt and embed the novel aptasensing interface via a user-friendly methodology.
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