Fibrillar forms of the Amyloid-β (Aβ) protein have been implicated in the early stages of Alzheimer's disease (AD), however there are no standardised assays for soluble Aβ oligomer biomarkers that provide the best indication of the disease progression [1,2]. As a step towards a fast and label-free method for testing different AD biomarkers, we have combined laser nano-textured substrates with a SERS mapping technique and validated it using soluble Aβ-40 oligomers [3-5]. The nano-textured SERS substrates provide fast (&5 min), label-free spectra associated with soluble Aβ-40 oligomers down to a concentration of 10 nM. Statistical analysis of the spectral intensities mapped over the substrate surface shows a quantitative correlation with the oligomer concentration. Schematics of experiments: SERS mapping of Aβ-40 (left figure: measured SERS intensity overlayed with an SEM image of ripples) was carried out on the laser nano-textured (ripple) surface of sapphire and statistical analysis of the SERS intensity was carried out for qualitative (a high SERS intensity at low probability) and quantitative (a moderate SERS intenisty at the highest probability) measures. Quantitative statistical analysis of SERS mapping data can be performed off line for cross correlations with other known SERS signatures.
Pharmaceuticals, microplastics, and oil spills are the most hazardous contaminants in aquatic environments. The COVID-19 pandemic enhanced pharmaceutical and microplastic contamination in aquatic environments. The present study aimed to investigate the prevalence of pharmaceutical and microplastic pollution on a global scale. This study assessed the results of pharmaceutical contamination in 25 countries and microplastic pollution in 13 countries. The findings show that pharmaceutical residues were detected in surface water, groundwater, and wastewater influents and effluents. In total, 43 types of pharmaceutical products were detected in 25 countries. Caffeine, acetaminophen, ibuprofen, sulfamethoxazole, and carbamazepine were the most abundant. In total, 32 types of polymers were detected in 13 countries. In the case of microplastics, polypropylene, polyethylene, polystyrene, and polyethylene terephthalate were the more abundant polymers. Particles with a size of 1–2.5 mm and 2.5–5 mm accounted for half of the microplastics present in 13 countries. This study provides new evidence of the importance of emerging pollutants in aquatic environments before and during the COVID-19 pandemic.
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