US20250283830
2025-09-11
Physics
G01N21/78
The process begins with the synthesis of fluorine-doped carbon dots (CDs) using a one-pot solvothermal method. This involves dissolving 4-(diethylamino)salicylaldehyde and sodium fluoride in deionized water to create an aqueous solution. This solution is then ultrasonically mixed with phosphoric acid, forming a mixture that is placed in a PTFE-lined reactor. The reaction occurs under heating at temperatures between 180°C and 220°C for 1 to 3 hours. After cooling, centrifugation is performed to eliminate unreacted materials, and the supernatant is dialyzed for 24 to 48 hours. Finally, the sample is lyophilized to produce the fluorine-doped CDs.
The fluorine-doped CDs are used as a chromogenic agent in creating an enrichment chromogenic membrane, combined with UiO-66-F4. The preparation begins by modifying polyvinylidene fluoride (PVDF) to produce αAA-PVDF, which is then dissolved with polyvinylpyrrolidone in DMF. After stirring and standing, the mixture is scrape-coated to form a substrate membrane, which is soaked in deionized water. A tannic acid solution is prepared separately, and the substrate membrane undergoes static immersion in this solution, followed by immersion in a dispersion containing UiO-66-F4 and the fluorine-doped CDs, resulting in the final chromogenic membrane.
This technology addresses the detection of perfluorinated compounds (PFCs), which are stable due to their fluorine content but pose environmental and health risks due to their persistence and bioaccumulation. Common PFCs like PFOS and PFOA are widely used but are difficult to detect due to low concentrations and complex matrices in aquatic environments. The enrichment chromogenic membrane provides an eco-friendly solution by simplifying detection processes for PFCs such as PFOA, PFOS, and PPVE.
A test kit incorporating the enrichment chromogenic membrane is described, featuring components like light sources, a collection window, camera mount, sample stage, and a microfluidic chip. The microfluidic chip contains an upper chip with sample inlet, microchannel, detection region, and the chromogenic membrane itself. The setup facilitates easy monitoring of PFCs in water samples by visualizing color changes that indicate PFC presence.
The developed fluorine-doped CD-modified enrichment chromogenic membrane offers significant advantages for detecting three specific PFCs in water environments. It simplifies the detection process by reducing pretreatment steps usually necessary due to sample complexity. This innovative approach not only enhances sensitivity and accuracy but also supports real-time monitoring of environmental pollutants with minimal interference from other substances.