Synergistic signal-amplification effect of silver nanowires and bifunctional monomers on molecularly imprinted electrochemical sensor for diuron analysis.

Molecularly imprinted polymers (MIP) have been widely owing to their specificity, however, their singular structure imposes limitations on their performance. Current enhancement methods, such as doping with inorganic nanomaterials or introducing various functional monomers, are limited and single, indicating that MIP performances require further advancement. In this work, a dual-modification approach that integrates both conductive inorganic nanomaterials and diverse bifunctional monomers was proposed to develop a multifunctional MIP-based electrochemical (MMIP-EC) sensor for diuron (DU) detection. The MMIP was synthesized through a one-step electrochemical copolymerization of silver nanowires (AgNWs), o-phenylenediamine (O-PD), and 3,4-ethylenedioxythiophene (EDOT). DU molecules could conduct fluent electron transfer within the MMIP layer through the interaction between anchored AgNWs and bifunctional monomers, and the abundant recognition sites and complementary cavity shapes ensured that the imprinted cavities exhibit high specificity. The current intensity amplified by the two modification strategies of MMIP (3.7 times) was significantly higher than the sum of their individual values (3.2 times), exerting a synergistic effect. Furthermore, the adsorption performance of the MMIP was characterized by examining the kinetics and isotherms of the adsorption process. Under optimal conditions, the MMIP-EC sensor exhibits a wide linear range (0.2 ng/mL to 10 µg/mL) for DU detection, with a low detection limit of 89 pg/mL and excellent selectivity (an imprinted factor of 10.4). In summary, the present study affords innovative perspectives for the fabrication of MIP-EC sensor with superior analytical performance.

Residues of atrazine and diuron in rice straw, soils, and air post herbicide-contaminated straw biomass burning.

This study investigates the environmental impact of burning herbicide-contaminated biomass, focusing on atrazine (ATZ) and diuron (DIU) sprayed on rice straw prior to burning. Samples of soil, biomass residues, total suspended particulate (TSP), particulate matter with an aerodynamic diameter ≤ 10 µm (PM10), and aerosols were collected and analyzed. Soil analysis before and after burning contaminated biomass showed significant changes, with 2,4-dichlorophenoxyacetic acid (2,4-D) initially constituting 79.2% and decreasing by 3.3 times post-burning. Atrazine-desethyl, sebuthylazine, and terbuthylazine were detected post-burning. In raw rice straw biomass, terbuthylazine dominated at 80.0%, but burning ATZ-contaminated biomass led to the detection of atrazine-desethyl and notable increases in sebuthylazine and terbuthylazine. Conversely, burning DIU-contaminated biomass resulted in a shift to 2,4-D dominance. Analysis of atmospheric components showed changes in TSP, PM10, and aerosol samples. Linuron in ambient TSP decreased by 1.6 times after burning ATZ-contaminated biomass, while atrazine increased by 2.9 times. Carcinogenic polycyclic aromatic hydrocarbons (PAHs), including benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), and benzo[b]fluoranthene (BbF), increased by approximately 9.9 to 13.9 times after burning ATZ-contaminated biomass. In PM10, BaA and BaP concentrations increased by approximately 11.4 and 19.0 times, respectively, after burning ATZ-contaminated biomass. This study sheds light on the environmental risks posed by burning herbicide-contaminated biomass, emphasizing the need for sustainable agricultural practices and effective waste management. The findings underscore the importance of regulatory measures to mitigate environmental contamination and protect human health.

Valoración del riesgo en salud en un grupo de población de Cali, Colombia, por exposición a plomo, cadmio, mercurio, ácido 2,4-diclorofenoxiacético y diuron, asociada al consumo de agua potable y alimentos / Evaluation of human health risk for a population from Cali, Colombia, by exposure to lead, cadmium, mercury, 2,4-dichloro-phenoxyacetic acid and diuron associated with water and food consumption

Introducción. La exposición a contaminantes como plaguicidas y metales pesados, se asocia a problemas de salud. Diversos estudios revelan la presencia de estos contaminantes en Cali; sin embargo, no existe información sobre las rutas principales de esa exposición y su riesgo implícito. Objetivo. Estimar los riesgos asociados a la exposición a cadmio, plomo y mercurio, y a los plaguicidas ácido 2,4-diclorofenoxiacético y diuron, debida al consumo de agua potable y alimentos en un grupo de población de Cali. Materiales y métodos. Se obtuvieron datos ambientales e información sobre la población, y se valoró el riesgo empleando los modelos de la Environmental Protection Agency (EPA) de los Estados Unidos. Resultados. Las concentraciones de los contaminantes evaluados estuvieron por debajo de las permisibles establecidas por el Ministerio de Ambiente, Vivienda y Desarrollo Territorial de Colombia (3 µg/L -1 de cadmio; 10 µg/L -1 de plomo; 1 µg/L -1 de mercurio; 1 µg/L - 1 de ácido 2,4 diclorofenoxiacético; 1 µg/L -1 de diuron). En las muestras de pescado "manteco" ( Peprilus snyderi ), se detectaron concentraciones de cadmio entre 20 y 80 µg/kg -1 por debajo del límite permisible establecido por la Organización Mundial de la Salud (100 µg/kg -1 ). Los resultados de la valoración mostraron que el riesgo cancerígeno y no cancerígeno atribuible a la ingestión de alimentos y de agua potable con presencia de los contaminantes evaluados, estaba por debajo de los valores máximos admisibles según la EPA. Conclusiones. Se cree que los hallazgos sobre contaminantes en estudios anteriores, pueden deberse a eventos puntuales de contaminación y se recomienda vigilar la bocatoma de agua y emitir alertas tempranas. El reporte sobre la presencia de cadmio en las muestras de pescado, sugiere que el control de la calidad de los alimentos por parte de las entidades reguladoras debe mejorar.

Introduction: Exposure to pollutants such as pesticides and heavy metals has been linked to health problems. Several studies have revealed the presence of these contaminants in Cali; however, there is no information available about the main routes of exposure and risk of these contaminants. Objective: To estimate the risk associated with the intake of cadmium, lead and mercury, and pesticides 2,4-D and diuron through the consumption of water and food in a population in Cali. Materials and methods: Population and environmental data were obtained, and a risk assessment was performed using United States Environmental Protection Agency guidelines. Results: The concentrations of the evaluated pollutants were below permissible levels as established by the Colombian Ministerio de Ambiente, Vivienda y Desarrollo Territorial (3 µg/L -1 of cadmium; 10 µg/L -1 of lead; 1 µg/L -1 of mercury; 1 µg/L -1 of 2,4 D; 1 µg/L -1 of diuron). Salema butterfish ( Peprilus snyderi ) samples contained levels of cadmium between 20 and 80 µg/kg -1 , which are below the permissible limit set by the World Health Organization (100 µg/kg -1 ). The results of the risk assessment indicated that the carcinogenic and non-carcinogenic attributable risk to population health from the intake of food contaminants was below the maximum level permitted by the United States Environmental Protection Agency. Conclusions: It is believed that the findings in previous studies on pollutants may have been due to specific contamination events; therefore, monitoring and early warning about water intake is recommended. Furthermore, the report of cadmium being found in fish consumed as food suggests the need for quality control by regulators.