Reducing dermal exposure to agrochemical carcinogens using a fluorescent dye-based intervention among subsistence farmers in rural Honduras

MOF@Au NPs/aptamer fluorescent probe for the selective and sensitive detection of thiamethoxam

The luminescence performance of fluorescent reagents plays a crucial role in fluorescence analysis. Therefore, in this study, a novel bi-ligand Zn-based metal-organic framework, Au nanoparticle (NP) fluorescent material was synthesized using a hydrothermal method with Zn as the metal source. Simultaneously, a DNA aptamer was introduced as a molecular recognition element to develop a Zn-based MOF@Au NPs/DNA aptamer fluorescent probe for the ultra-trace detection of thiamethoxam residues in agricultural products. The probe captured different concentrations of the target molecule, thiamethoxam, through the DNA aptamer, causing a conformational change in the DNA aptamer and bursting the fluorescence of the probe, therefore establishing a fluorometric method for thiamethoxam detection. This method is highly sensitive due to the excellent luminescence properties of the Zn-based MOF@Au NPs, and the DNA aptamer can specifically recognize thiamethoxam, offering high selectivity. The linear range of the method was 2.5-6000 × 10-11  mol L-1 , with a detection limit of 8.33 × 10-12  mol L-1 . This method was applied to the determination of actual samples, such as bananas, and the spiked recovery rate was found to be in the range 84.05-109.07%. Overall, the proposed probe has high sensitivity, high selectivity, and easy operation for the detection of thiamethoxam residues in actual samples.

Fluorescent Marker as a Tool to Improve Strategies to Control Contaminated Surfaces and Decrease Danger of Cross-Contamination in Dental Clinics, during and beyond the COVID-19 Pandemic

The COVID-19 pandemic posed an increased threat to dental personnel and patients. Close encounters with patients' breath and saliva and the use of intraoral rotating instruments which disperse microscopic airborne particles both increase the possibility of environmental infection. In this study, fluorescent marker (FM) was used to assess and enhance surface cleanliness in the dental clinics and public areas of a major dental school. Initially, 574 surfaces in various areas of a dental school were marked with FM for 3 consecutive months to monitor the surface cleanliness. The initial evaluation results were visually presented to both students and para-dental and cleaning personnel during a designated educational session, and were used to stress the importance of preventing cross-contamination. Following educational intervention, 662 surfaces were re-examined for an additional 3 months, using the same method. A significant improvement in the surfaces' cleanliness (ANOVA, F₍₁₎ = 10.89, p < 0.005) was observed post-intervention. The results were more prominent in students' clinics, which were the students' cleaning responsibility. The results show that fluorescent markers can serve as an educational tool to improve strategies to control contaminated surfaces in large clinics, such as dental schools. Their use can substantially decrease the hazard of cross-contamination during the pandemic and beyond.