Facile synthesis of gold nanostars for the duplex detection of pesticide residues in grapes using SERS.

In recent years, concerns have been raised regarding the contamination of grapes with pesticide residues. As consumer demand for safer food products grows, regular monitoring of pesticide residues in food has become essential. This study sought to develop a rapid and sensitive technique for detecting two specific pesticides (phosmet and paraquat) present on the grape surface using the surface-enhanced Raman spectroscopy (SERS) method. Gold nanostars (AuNS) particles were synthesized, featuring spiky tips that act as hot spots for localized surface plasmon resonance, thereby enhancing Raman signals. Additionally, the roughened surface of AuNS increases the surface area, resulting in improved interactions between the substrate and analyte molecules. Prominent Raman peaks of mixed contaminants were acquired and used to characterize and quantify the pesticides. It was observed that the SERS intensity of the Raman peaks changed in proportion to the concentration ratio of phosmet and paraquat. Moreover, AuNS exhibited superior SERS enhancement compared to gold nanoparticles. The results demonstrate that the lowest detectable concentration for both pesticides on grape surfaces is 0.5 mg/kg. These findings suggest that SERS coupled with AuNS constitutes a practical and promising approach for detecting and quantifying trace contaminants in food. PRACTICAL APPLICATION: This research established a novel surface-enhanced Raman spectroscopy (SERS) method coupled with a simplified extraction protocol and gold nanostar substrates to detect trace levels of pesticides in fresh produce. The detection limits meet the maximum residue limits set by the EPA. This substrate has great potential for rapid measurements of chemical contaminants in foods.

A COVID-19 Young Male Patient with Pneumonia and Liver Injury.

BACKGROUND: COVID-19 caused by SARS-CoV-2 has been inducing an ongoing global health and economic emergency. Although viral pneumonia is the most striking presentation for COVID-19 patients, it has been noticed that some patients may also be accompanied with an abnormal liver function. METHODS: CT was performed in both lungs, and routine bloodwork and the blood metabolic panel were measured. RESULTS: Here, we report on a young male patient without any history of live diseases who suffered simultaneously both SARS-CoV-2 caused pneumonia and hepatitis as evidenced by increased serum bilirubin together with increased serum transaminases. CONCLUSIONS: Studies on mechanisms whereby SARS-CoV-2 causing liver damages might provide more information about the pathogenesis of COVID-19 and help management of this global health emergency.