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Utilizing infrared spectroscopy coupled with batch equilibrium methods, the adsorption and desorption characteristics of the novel Insecticide fluchlordiniliprole were assessed in four different soil types. It was found that fluchlordiniliprole's adsorption and desorption in these soils were consistent with the Freundlich isotherm, exhibiting adsorption capacities (K F-ads) ranging from 8.436 to 36.269. Temperature fluctuations, encompassing both high and low extremes, impaired the ability of soil to adsorb fluchlordiniliprole. In addition, adsorption dynamics were modulated by several other factors, including soil pH, ionic strength, amendments (e.g., biochar and humic substances), and the presence of various surfactants and microplastics. Although capable of leaching, fluchlordiniliprole exhibited weak mobility in most soils. Therefore, it appears that fluchlordiniliprole seems to pose a threat to surface soil and aquatic biota, but a minimal threat to groundwater. This research examines the dynamics of fluchlordiniliprole in soil, an will aid in maintaining ecological safety and managing agricultural pesticides. The study's comprehensive analysis of adsorption, desorption, and soil migration patterns significantly contributes to our understanding of pesticide interactions with diverse soil types. The results of this study will enable the development of environmentally responsible agricultural practices. • Fluchlordiniliprole adsorption-desorption follows the Freundlich isotherm model. • Adsorption efficiency varies with pH, temperature, and organic matter content. • FTIR reveals specific functional group interactions with soil components. • Low leaching potential indicates minimal groundwater contamination risk. • Humic acid and biochar significantly enhance soil adsorption capacity. [ABSTRACT FROM AUTHOR]

Benzovindiflupyr is a succinate dehydrogenase inhibitor fungicide that targets mitochondrial function for disease control. In this study, we investigated the adsorption–desorption and leaching behavior of benzovindiflupyr in eight soil types using the batch equilibrium method and the soil column leaching method. A Freundlich model (r 2 > 0.9959) was used to better characterize the adsorption-desorption process in eight soil types, with adsorption coefficients (K F-ads) ranging from 2.303 to 17.886. K F-ads was significantly and positively correlated (p < 0.05) with the organic carbon content. High temperatures and increased initial pH of aqueous solutions led to a decrease in benzovindiflupyr adsorption in the soil. The adsorption was also influenced by factors such as ionic strength, humic acid, surfactant type, microplastic type, and particle size and concentration. Moreover, benzovindiflupyr exhibited low leachability in all four soils selected, but different leaching solutions affected the risk of benzovindiflupyr migration to groundwater. Overall, this study provides insights into the adsorption characteristics of benzovindiflupyr in different soils and provides key information for environmental risk assessment. [Display omitted] • Study of the adsorption-desorption and leaching behavior of benzovindiflupyr in soil. • The adsorption-desorption process can be better described by the Freundlich model. • First study of benzovindiflupyr adsorption on microplastic-soil mixtures. • Risk of benzovindiflupyr migration to groundwater as affected by drench solutions. • The adsorption mechanism of benzovindiflupyr in soil was evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Al F at channel intersection of HZSM-5 was identified by toluene adsorption. • The affinity of toluene/Al F was enhanced by the ion exchange of H+ by Na+. • Stepwise TPD (STPD) method was designed to quantitate the toluene desorbed from Na+. • The toluene-STPD method is not affected by the coexistence of Al pair and single Al. Precise analysis of the framework Al (Al F) at channel intersections of HZSM-5 zeolite is the basis of fine tuning of the spatial distribution of active sites within different pores which is critical to promote the catalytic performance in various applications. However, existing technologies cannot provide reliable quantitative results either in theory or practice due to the co-existence of Al pair and single Al. Here we report a new method based on toluene adsorption–desorption. As a promising probe, toluene can be preferentially adsorbed on Al F at channel intersection under low loading (≤4 molecules/unit cell) due to spatial matching and energetic heterogeneity. After strengthening the toluene/Al F affinity through replacing H+ by Na+ and designing a new stepwise TPD technique (toluene-STPD), the contents of Al F atoms at channel intersections of HZSM-5 samples were successfully calculated by counting the desorbed toluene molecules based on the 1:1 stoichiometric relationship between adsorbed toluene and Al F. [ABSTRACT FROM AUTHOR]

The low cost and high efficiency of microwave-assisted regeneration render it a viable alternative to conventional regeneration methods. To enhance the regeneration performance, we developed a coupled electromagnetic, heat, and mass transfer model to investigate the heat and mass transfer mechanisms of activated carbon during microwave-assisted regeneration. Simulation results demonstrated that the toluene desorption process is governed by temperature distribution. Changing the input power and flow rate can promote the intensity of hot spots and adjust their distribution, respectively, thereby accelerating toluene desorption, inhibiting readsorption, and promoting regeneration efficiency. Ultimately, controlling the input power and flow rate can flexibly adjust toluene emissions to satisfy the processing demands of desorbed toluene. Taken together, this study provides a comprehensive understanding of the heat and mass transfer mechanisms of microwave-assisted regeneration and insights into adsorbent regeneration. [Display omitted] • A coupled model used to describe heat and mass transfer for toluene desorption. • Toluene desorption process is governed by the intensity and distribution of hot spots. • The readsorption can be inhibited by adjusting temperature distribution. • Toluene emissions can be flexibly adjusted by changing input power and flow rate. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) and pesticides are two categories contaminants with proposed negative impacts to aqueous ecosystems, and adsorption of pesticides on MPs may result in their long-range transport and compound combination effects. Florpyrauxifen-benzyl, a novel pyridine-2-carboxylate auxin herbicide has been widely used to control weeds in paddy field, but the insights of which are extremely limited. Therefore, adsorption and desorption behaviors of florpyrauxifen-benzyl on polyvinyl chloride (PVC), polyethylene (PE) and disposable face masks (DFMs) in five water environment were investigated. The impacts of various environmental factors on adsorption capacity were evaluated, as well as adsorption mechanisms. The results revealed significant variations in adsorption capacity of florpyrauxifen-benzyl on three MPs, with approximately order of DFMs > PE > PVC. The discrepancy can be attributed to differences in structural and physicochemical properties, as evidenced by various characterization analysis. The kinetics and isotherm of florpyrauxifen-benzyl on three MPs were suitable for different models, wherein physical force predominantly governed adsorption process. Thermodynamic analysis revealed that both high and low temperatures weakened PE and DFMs adsorption, whereas temperature exhibited negligible impact on PVC adsorption. The adsorption capacity was significantly influenced by most environmental factors, particularly pH, cations and coexisting herbicide. This study provides valuable insights into the fate of florpyrauxifen-benzyl in presence of MPs, suggesting that PVC, PE and DFMs can serve as carriers of florpyrauxifen-benzyl in aquatic environment. [Display omitted] • PVC, PE and DFMs act as potential vectors of florpyrauxifen-benzyl in water environment. • Adsorption kinetics and isotherms of florpyrauxifen-benzyl on PVC, PE and DFMs fit well with different models. • Various environmental factors significantly influenced the adsorption capacity. • The adsorption process was predominantly governed by physical force. [ABSTRACT FROM AUTHOR]

Molybdenum (Mo) is an essential trace element for human, animal and plant health. Mo deficiency in soils has frequently been reported, especially under P-deficient conditions. However, Mo is also a potentially toxic contaminant to soils and aquifers that may pose significant threat to ecological and human health. This review article illustrates briefly about Mo, its production and use, its natural occurrence, its fate and behavior in the soil-water system, and its retention mechanisms in soils. Furthermore, a range of transport models (multi-reaction model, second order model, stir-flow model, and competitive model) for describing and predicting Mo fate and transport behavior in the environment have been reviewed. It was shown that equilibrium Langmuir and Freundlich equations can be extended to simulate the pH dependent and time-dependent sorption and transport in soils. An advantage of modified Freundlich and Langmuir approaches is that they are relatively less complex and require fewer parameters. On the other hand, geochemical models, which are based on surface complexation concepts, were incorporated into kinetic models to accurately describe the reactive transport of Mo in soil components under a wide range of environmental conditions. [ABSTRACT FROM AUTHOR]

The use of treated wastewaters (TWW) in agriculture is widening in areas suffering drought, such as southern Europe, to preserve freshwater supply for human consumption. The composition of TWW, especially concerning their organic carbon (OC) content, has been demonstrated to influence the processes governing the behavior of non-ionic pesticides in soils. Three OC-poor agricultural soils (SV, RM1 and RM3) from the province of Granada (Spain) were chosen for the assessment of the adsorption and desorption of the herbicide dimethenamid (DIM) and the fungicide fenarimol (FEN). TWW and sewage sludge extracts at different dissolved OC (DOC) concentrations (30, 90 and 300 mg L −1 ) were considered to evaluate their effect on pesticide adsorption-desorption. As expected by their properties, DIM and FEN were weakly and moderately adsorbed to the soils, respectively. Soil OC seemed to be the major factor controlling FEN adsorption, whereas the mineral fraction played a key role in DIM adsorption, especially in RM1 with high clay:OC ratio. Although TWW did not significantly modify the adsorption of pesticides, it enhanced DIM desorption from the three soils. Adsorption of FEN to SV and RM3 was directly related to the concentration of DOC, possibly due to co-sorption phenomena. Hysteretic desorption was found in all cases, indicating partially reversible adsorption. While FEN desorption was not altered by the solutions, the use of sludge extracts at the highest DOC concentration (300 mg L −1 ) enhanced DIM desorption as occurred with TWW. Interactions with DOC in solution seemed to predominate for this less hydrophobic compound, thus increasing the risk of natural waters contamination if TWW will be used. [ABSTRACT FROM AUTHOR]

Three fluoroquinolone antibiotics agents (FQs) in groundwater and reclaimed water have been investigated in Changzhou and Beijing, China. The occurrence of ofloxacin (OFL), enrofloxacin (ENR) and norfloxacin (NOR) is in nanograms per liter and has 100% frequency. The concentration order of FQs in reclaimed water is NOR>OFL>ENR, whilst the order in groundwater is NOR>ENR>OFL. And then the single and mixture adsorption-desorption have been studied and showed that (i) silty clay loam has higher sorption capacity than loamy sand, (ii) competitive adsorption exists when the three selected FQs coexist, (iii) ENR has a significantly priority sorption to NOR, whilst OFL has a least sorption among the mixture, (iv) there is no significant difference between the desorption results of mixture and the indivdual compound in relatively low concentration, (v) the formed chemical bonds and the irreversible combination of adsorption point are the significant influential factors for explaining desorption hysteresis of the selected FQs. Based on the above study, transport model and risk quotient have been performed, and the calculated risk quotient reveals that: (i) the selected FQs risk order in reclaimed water is OFL>ENR>NOR, (ii) in groundwater, OFL and ENR pose a higher risk than NOR no matter whether considering the long time groundwater recharge. This study will help policy makers to decide which FQs need to be covered in the priority substance lists defined in legislative frameworks. [ABSTRACT FROM AUTHOR]

Two supramolecular hybrids [Ni(mbpy) 3 ] 2 [V 2 W 4 O 19 ]·6H 2 O ( 1 ) and [Ni(mbpy) 3 ] 2 [VW 12 O 40 ] ( 2 ) (mbpy=4,4ʹ-dimethyl-2,2ʹ-bipyridyl) had been synthesized and characterized. Single crystal X-ray diffraction analyses revealed that the anionic moieties in two hybrids belong to typical Lindqvist and α-Keggin-type structures, respectively. The counter ion [Ni(mbpy) 3 ] 2+ units were anchored to the polyanions via non-covalent intermolecular interactions. These supramolecular hybrids exhibit reversible adsorption–desorption performance for organic dye methylene blue (MB). Hybrid 2 shows a fast adsorption behavior towards MB and a relatively high value can be reached within 5 min in dark. Both 1 and 2 are structurally stable and can be easily separated from the reaction system for reuse. [ABSTRACT FROM AUTHOR]

Abstract: In this work, natural palygorskite impregnated with zero-valent iron (ZVI) was prepared and characterized. The combination of ZVI particles on surface of fibrous palygorskite can help to overcome the disadvantage of ultra-fine powders which may have strong tendency to agglomerate into larger particles, resulting in an adverse effect on both effective surface area and catalyst performance. There is a significant increase of methylene blue (MB) decolourized efficiency on acid treated palygorskite with ZVI grafted, within 5min, the concentration of MB in the solution was decreased from 94mg/L to around 20mg/L and the equilibration was reached at about 30–60min with only around 10mg/L MB remained in solution. Changes in the surface and structure of prepared materials were characterized using X-ray diffraction (XRD), infrared (IR) spectroscopy, surface analysing and scanning electron microscopy (SEM) with element analysis and mapping. Comparing with zero-valent iron and palygorskite, the presence of zero-valent iron reactive species on the palygorskite surface strongly increases the decolourization capacity for methylene blue, and it is significant for providing novel modified clay catalyst materials for the removal of organic contaminants from waste water. [Copyright &y& Elsevier]

Abstract: Single pulse TAP experiments were chosen for obtaining estimates of intra-particle diffusion coefficients and better insight into adsorption–desorption dynamics and equilibria for isobutane and n-butane in commercially available beta and USY zeolite. This technique provides a unique way of directly estimating transport and sorption processes at extremely low surface coverage (θ i →0), in the absence of an inert carrier stream, with no external mass transfer resistance, and with a negligible thermal effect. The use of a thin zone TAP reactor configuration enables the use of small zeolite particles without causing high bed resistance. A theoretical model that considers transport and adsorption–desorption phenomena in the inter-particle and intra-particle space is developed and numerically solved. Numerical experiments demonstrate the ability of the model to represent the actual experimental response curves. It is shown that reliable values of intra-particle diffusivity and adsorption–desorption constants can be obtained from the TAP single pulse experiments when the three dimensionless constants of the model (the ratio of characteristic diffusion time in the micro-reactor to characteristic diffusion time in zeolite pore), (the ratio of characteristic desorption time to characteristic adsorption time), and (the ratio of characteristic diffusion time in the micro-reactor to characteristic desorption time) fall within a prescribed range. [Copyright &y& Elsevier]

Abstract: Amino acid–smectite interaction may have catalyzed prebiotic reactions essential for the emergence of life. Lysine solutions (0.05 M) were reacted with Na-smectite in adsorption–desorption experiments. The lysine–smectite complexes were heated at 80 °C for 10 days to investigate (1) possible slow processes taking place at surface temperature that would be accelerated at higher temperature and (2) processes taking place in hydrothermal systems. Three sets of experiments were performed: thermal treatment in closed tubes and water added regularly; thermal treatment in closed tubes without adding water; and thermal treatment in open tubes and no added water. After lysine desorption (displacement with 0.1 M CaCl2), the solutions were investigated using circular dichroism (CD) and the smectite samples using FTIR and CHN elemental analysis. CD spectra were dependent on the solution pH, which was controlled by lysine protonation state. The lysine protonation state was altered by the adsorption–desorption process, with a higher Lys+/Lys± ratio after desorption. The CD and CHN analyses show that the thermal treatment in a moist state causes stronger smectite–lysine binding. FTIR data suggest that the stronger binding is caused by more or stronger H bonds between –NH+ 3 lysine groups and smectite basal O atoms. [Copyright &y& Elsevier]

Abstract: Adsorption irreversibility of Zn(II) on TiO2 at various temperatures was studied using a combination of classical macroscopic methods and extended X-ray absorption fine structure (EXAFS) spectroscopy. When the temperature was increased from 5 to 40 °C, the Zn(II) adsorption capacity increased by 130%, and adsorbed Zn(II) became more reversible. The standard Gibbs free energy change () of the adsorption reaction at 5, 20, and 40 °C was determined to be , , and , respectively. And the standard enthalpy () and entropy () were and , respectively. EXAFS spectra results showed that the hydrated Zn(II) was adsorbed through fourfold coordination with an average Znstance of . Two Zn distances of and were observed, which corresponded to an edge-sharing linkage mode (strong adsorption) and a corner-sharing linkage mode (weak adsorption), respectively. As the temperature increased from 5 to 40 °C, the number of strong adsorption sites () remained relatively constant while the number for the weak adsorption sites () increased by 31%. These results indicate that the net gain in adsorption capacity and the decreased adsorption irreversibility at elevated temperatures were due to the increase in available weak adsorption sites () or the decrease in the ratio of . Both the macroscopic sorption/desorption equilibrium data and the molecular level evidence of this study suggest that in a given environmental system (e.g., soils or natural waters) zinc and other similar heavy metals are likely more mobile at higher temperatures. [Copyright &y& Elsevier]

Abstract: The environmental and health effects of the contamination of soils by heavy metals depend on the ability of the soils to immobilize these contaminants. In this work, the adsorption and desorption of Cu and Zn in the surface layers of 27 acid soils were studied. Adsorption of CuII from 157–3148 μmol L−1 solutions was much greater than adsorption of ZnII from solutions at the same concentration. For both Cu and Zn, the adsorption data were fitted better by the Freundlich equation than by the Langmuir equation. Multiple regression analyses suggest that Cu and Zn adsorption depends to a significant extent on pH and CEC: for both metals these variables accounted for more than 80% of the variance in the Freundlich pre-exponential parameter , and pH also accounted for 57% of the variance in for Zn and, together with carbon content, for 41% of the variance in for Cu. The percentage of adsorbed metal susceptible to desorption into 0.01 M NaNO3 was greater for Zn than for Cu, but in both cases depended significantly on pH, decreasing as pH increased. In turn, both pHH2O and pHKCl are significantly correlated with cation exchange capacity. Desorption of metal adsorbed from solutions at relatively low concentration (787 μmol L−1) exhibited power-law dependence on , the quotient expressing distribution between soil and soil solution in the corresponding adsorption experiment, decreasing as increasing reflected increasing affinity of the soil for the metal. The absence of a similarly clear relationship when metal had been adsorbed from solutions at relatively high concentration (2361 μmol L−1) is attributed to the scant between-soil variability of at these higher concentrations. In general, adsorption was greater and subsequent desorption less in cultivated soils than in woodland soils. [Copyright &y& Elsevier]

Microscopic structures of Zn(II) surface complexes adsorbed at the manganite (γ-MnOOH)–water interface were studied using extended X-ray absorption fine structure (EXAFS) spectroscopy. Quantitative analysis of the first sphere showed that, in a 0.1 M NaNO3 solution of pH 7.5, Zn(II) was adsorbed as a mixture of tetrahedral and octahedral structure (ZnO4,6 polyhedra) and the average Zn&z.sbnd;O distance was 2.00±0.01 A˚. EXAFS analysis of the second sphere showed that two typical atomic Zn&z.sbnd;Mn distances of 3.07±0.01 and 3.52±0.02 A˚ existed in the surface complexes, indicating that there were two types of linkage, i.e., the edge-linkage of high affinity and the corner-linkage of low affinity, between the ZnO4,6 polyhedra and the MnO6 octahedra of the manganite. Macroscopic adsorption–desorption experiments showed that adsorption of Zn(II) onto manganite was largely irreversible and the stronger edge-linkage mode was found to be responsible for the adsorption irreversibility. This result provided direct evidence from the molecular level for the basic hypothesis of the metastable-equilibrium adsorption (MEA) theory that adsorption density is not a thermodynamic state variable because a given value of adsorption density could have different values of chemical potential, depending on the proportion between the edge and corner linkage modes. [Copyright &y& Elsevier]

Cephalosporins are one of the most widely used antibiotics. When cephalosporins are discharged into the environment, they not only induce the production of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARBs) but also cause toxic effects on animals and plants. Due to their complicated environmental behavior and lack of relevant data, the environmental behavior remains unclear. In this study, the adsorption-desorption and degradation characteristics of the third-generation cephalosporin drug ceftiofur (CEF) were investigated in three agricultural soils (sandy loam, loam and clay). According to the relevant parameters of the Freundlich adsorption isotherm (the K f range was 57.63–122.44 μg1–1/n L1/n kg−1), CEF was adsorbed moderately in the soils and had the potential to migrate into groundwater. CEF exhibited low persistence in the soils and faster degradation than other antibiotics, such as tetracyclines and fluoroquinolones. The degradation half-lives (DT50) of CEF in soils ranged from 0.76 days to 4.31 days. Adding feces, increasing the water content, providing light and increasing the temperature significantly accelerated the degradation of CEF in soils. The DT50 values of CEF in soils were significantly prolonged when the soils were sterilized, indicating that both physical degradation and biodegradation played important roles in the degradation of CEF in soils. The DT50 values of CEF in soils were significantly prolonged at high concentrations, indicating that the degradability of CEF in soils was affected by the initial concentration. No significant differences were observed in the DT50 values for the different soil types (p > 0.05). This study provides useful information about the environmental behavior of CEF and improves the environmental risk assessment of CEF. ● This is the first report of the adsorption-desorption characteristics of CEF in soil. ● CEF has the risk of polluting groundwater in low clay and organic carbon content soils. ● The degradation of CEF in soil is fast, both biodegradation and physical degradation play an important role. ● The ecotoxicity of low concentration CEF in environment is worth further study. [ABSTRACT FROM AUTHOR]

In this work batch-type experiments were used to study the adsorption of the antibiotics doxycycline (DC), enrofloxacin (ENR), and sulfamethoxypyridazine (SMP) in cultivation soils, before and after the removal of soil organic matter. Organic matter removal by calcination resulted not only in C and N removal, but also in increased soil pH, exchangeable basic cations and surface area values. The results indicate a very different behavior depending on the type of antibiotic, showing the adsorption sequence DC > ENR > SMP. Specifically, DC adsorption was very high in untreated soil samples (with organic matter), and was still high (although decreased) after the removal of soil organic matter. Furthermore, the adsorption behavior of DC was clearly dependent on the pH of the medium. Regarding ENR, it also showed high adsorption, although to a lesser extent than DC. However, when soil organic matter was removed, ENR adsorption significantly decreased in all soil samples. As regards SMP, it was adsorbed to a much lesser extent, and the removal of soil organic matter caused an additional drastic decrease in adsorption, reaching negligible values in some samples. Desorption followed the reverse sequence of adsorption, specifically in the order DC < ENR < SMP. In the case of DC, desorption was negligible, both in samples with and without organic matter, while for ENR and SMP, desorption clearly increased for soil samples where organic matter was removed. These results may be of relevance as regards environmental quality and public health, especially to facilitate a correct use of soils and organic amendments in areas that receive the application of substances containing the investigated antibiotics. [Display omitted] • Adsorption of three antibiotics in soils following the sequence DC > ENR > SMP. • DC adsorption was very high in raw soil and after the removal of soil organic matter. • ENR also showed high adsorption, although to a lesser extent than DC. • SMP was adsorbed to a much lesser extent, with drastic decrease after removing SOM. • Desorption followed the reverse sequence of adsorption, being negligible for DC. [ABSTRACT FROM AUTHOR]

The adsorption–desorption behavior of methylene blue, acid orange 7, bisphenol A, and phenol on the synthesized graphene-based nanomaterials were studied. For this purpose, adsorption experiments were conducted in a batch setup and different parameters such as contact time, pH, adsorbent dose concentration, and initial micropollutant concentration were considered. In addition, linear and nonlinear kinetic and isotherm models were evaluated. The nonlinear pseudo-second-order models (R2 > 0.98), Elovich kinetic models (R2 > 0.94), and Langmuir isotherm models (R2 > 0.98) best fitted the experimental data. Because of the high specific surface area and the type of oxygen functional groups, mechanochemically synthesized graphite oxide exhibited high adsorption capacities for methylene blue, acid orange 7, bisphenol A, and phenol, with a maximum uptake of 288, 232, 110, and 68 mg g−1, respectively. Furthermore, the total costs of applying the mechanochemically synthesized graphite oxide were estimated in the adsorption process, revealing that these nanomaterials offer better uptake values than porous carbon. Image 1 • Graphene based nanomaterial is appropriate for pollutants removal over short time and high efficiency. • Adsorption capacities of dyes are higher than phenolic compounds. • Adsorption process can be accurately more described by nonlinear models. • Regeneration of Graphene based nanomaterial is proved with high rates. • The cost of adsorption process is highlighted and estimated 0.42 € m−3. [ABSTRACT FROM AUTHOR]

An aptamer-based colorimetric lateral flow assay was developed for the detection of human epidermal growth factor receptor 2 (HER2). In this study, two approaches were examined using HER2 binding aptamers and gold nanoparticles. The first method used was a solution-based adsorption-desorption colorimetric approach wherein aptamers were adsorbed onto the gold nanoparticle surface. Upon the addition of HER2, HER2 binds specifically with its aptamer, releasing the gold nanoparticles. Addition of NaCl then induces the formation of gold nanoparticle aggregates. This leads to a color change from red to blue and a detection limit of 10 nM was achieved. The second method used an adsorption-desorption colorimetric lateral flow assay approach wherein biotin-modified aptamers were adsorbed onto the gold nanoparticle surface in the absence of HER2. In the presence of HER2, HER2 specifically binds with its aptamer leading to release of the gold nanoparticles. These solutions were applied to the lateral flow assay format and a detection limit of 20 nM was achieved. Both colorimetric and lateral flow assays are inexpensive, simple, rapid to perform and produce results visible to the naked-eye. Image 1 • Aptamer-based colorimetric and lateral flow assays (LFAs) for human epidermal growth factor receptor 2 (HER2) detection were proposed. • The adsorption-desorption mechanism for aptamer colorimetric and LFA development was employed. • These approaches exhibit a lower LOD compared to other aptasensor methods reported earlier. [ABSTRACT FROM AUTHOR]

Antibiotics spread into the environment can cause soil and water degradation. Specifically, tetracycline antibiotics (TCs) are among those most consumed in veterinary medicine, and near 90% of the doses administered to animals are excreted as original compounds, due to poor absorption. In this study we investigated competitive soil adsorption/desorption for three tetracycline antibiotics (tetracycline: TC, oxytetracycline: OTC, and chlortetracycline: CTC), usually spread on soils by slurry fertilization, affecting to soil degradation due to chemical pollution. The study was carried out on six soils selected according to their pH values (4.49–7.06), and organic matter contents (1.07–10.92%). The competitive experiments were performed in ternary systems (adding all three TCs simultaneously, using five equal and increasing concentrations, from 17 to 200 μmol L−1). The results were compared with those obtained in simple systems (adding individual antibiotics separately), for the same final concentration (in this case, 200 μmol L−1) and for different concentrations (200 μmol L−1 in the simple systems, versus 600 μmol L−1 in the ternary systems, resulting from the sum of 200 μmol L−1 of each of the three antibiotics). In all cases, batch-type adsorption/desorption experiments were carried out, with 24 h as contact time. Those soils with higher organic matter content adsorbed 100% of the TCs, with desorption being always lower than 3%. In soils with less organic matter, adsorption decreased as the dose of added antibiotic increased, due to competition for adsorption sites. CTC was the most retained among the three TCs (up to 20% more than the other when high doses of antibiotic were added). In the simple systems, percentage adsorption was always high (>85%) for the three TCs; however, percentage adsorption decreased in the ternary systems, reaching just 65% and 40% (for equal and different ionic strength, respectively) in soils with low organic matter contents. These results show the environmental and public health relevance of competition among the three TCs. In fact, the highest risk of entering the food chain takes place when these antibiotics are spread together on soils with low organic matter content, especially in the case of TC and CTC, which are the least adsorbed and the most desorbed molecules. Image 1 • Soils with higher organic matter content adsorbed 100% of the three tetracyclines. • Soils with less organic matter: adsorption decreased when added antibiotic increased. • Chlortetracycline was the most retained (up to 20% more than the other two). • In ternary competitive systems adsorption decreases, reaching just 65% and 40%. • Environmental and public health relevance of competition among tetracyclines. [ABSTRACT FROM AUTHOR]