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Herein, the usage of polyacrylic acid (AA) based and N,N′‐bis(acryloyl)cystamine (BAC) cross‐linked microgel (AA‐BAC) as a doxorubicin (DOX) carrier and stimuli‐responsive material for the controllable drug release is described. The carboxylic groups of AA provide a pH‐responsive and DOX‐holding ability of the polymer matrix, while sulfur groups of BAC provide a covalent immobilization of the AA‐BAC microgel onto the gold electrode surface. The microgel is responsive to electrochemically generated pH decrease due to ascorbate oxidation. As a result of the local pH drop on the electrode interface electrostatic attraction between the carrier and the positively charged DOX diminishes, which together with the shrinkage of the matrix results in the controlled release of DOX from the microgel. The electrodes modified by microgel based on N,N′‐methylene‐bis‐acrylamide (BIS) as a crosslinker are used as a control. However, AA‐BIS microgel does not contain sulfur groups and it can only be not explicitly adsorbed on the gold electrode while the efficacy of this modification is significantly worse compared to covalent immobilization of AA‐BAC via sulfur groups of BAC. Thus, electrode surface area covered by adsorbed (AA‐BIS)‐DOX microgel is approximately estimated as 34% compared to 90% for covalently immobilized (AA‐BAC)‐DOX microgel. 

Abstract The presence of poly‐ and perfluoroalkyl substances (PFAS) in the environment is associated with adverse health effects but measuring PFAS is challenging due to the associated high cost and technical complexities of the analysis. Here, the reactivity of atomically precise metal‐oxo clusters is reported and the foundation for their use is provided as fluorescent nanosensors for PFAS detection. The material comprises crystalline, water soluble, hexanuclear cerium‐oxo clusters [Ce₆(µ₃‐O)₄(µ₃‐OH)₄]¹²⁺decorated with glycine molecules (Ce‐Gly) characterized by fluorescence emission at 353 nm. The Ce‐Gly fluorescence is found sensitive to long chain carboxylated PFAS of CF₃–(CF₂)_n–, where n ≥ 6, such as perfluorooctanoic, perfluorononanoic and perfluorodecanoic acids. This unique reactivity leads to a change in the emission spectra in a concentration dependent manner, enabling PFAS detection through ligand exchange and aggregation‐induced emission (AIE) enhancement. No significant cross‐reactivity from potentially co‐existing species, including sulfonated PFAS, octanoic and dodecanoic acids, humic acid, and inorganic ions is observed. With an optimal concentration of 3.3 µg mL⁻¹Ce‐Gly, the method demonstrated detection limits of 0.24 ppb for PFOA and 0.4 ppb for PFNA. These findings highlight the potential of fluorescence‐based detection strategies utilizing nanoscale probes such as Ce‐Gly as fluorescent probes and nanosensors for PFAS. 

Abstract A metal–organic framework (MOF), ZIF‐8, which is stable at neutral and slightly basic pH values in aqueous solutions and destabilized/dissolved under acidic conditions, is loaded with a pH‐insensitive fluorescent dye, rhodamine‐B isothiocyanate, as a model payload species. Then, the MOF species are immobilized at an electrode surface. The local (interfacial) pH value is rapidly decreased by means of an electrochemically stimulated ascorbate oxidation at +0.4 V (Ag/AgCl/KCl). Oxygen reduction upon switching the applied potential to −0.8 V allows to return the local pH to the neutral/basic pH, then stopping rapidly the release process. The developed method allows electrochemical control over stimulated or inhibited payload release processes from the MOF. The pH variation proceeds in a thin film of the solution near the electrode surface. The switchable release process is realized in a buffer solution and undiluted human serum. As the second option, the pH decrease stimulating the release process is achieved upon an enzymatic reaction using esterase and ester substrate. This approach potentially allows the release activation controlled by numerous enzymes assembled in complex biocatalytic cascades. It is expected that related electrochemical or biocatalytic systems can represent novel signal‐responding materials with switchable features for delivering (bio)molecules within biomedical applications. 

The spatial distribution of disease cases can provide important insights into disease spread and its potential risk factors. Identifying disease clusters correctly can help us discover new risk factors and inform interventions to control and prevent the spread of disease as quickly as possible. In this study, we propose a novel scan method, the Prefiltered Component‐based Greedy (PreCoG) scan method, which efficiently and accurately detects irregularly shaped clusters using a prefiltered component‐based algorithm. The PreCoG scan method's flexibility allows it to perform well in detecting both regularly and irregularly‐shaped clusters. Additionally, it is fast to apply while providing high power, sensitivity, and positive predictive value for the detected clusters compared to other scan methods. To confirm the effectiveness of the PreCoG method, we compare its performance to many other scan methods. Additionally, we have implemented this method in thesmercR package to make it publicly available to other researchers. Our proposed PreCoG scan method presents a unique and innovative process for detecting disease clusters and can improve the accuracy of disease surveillance systems. 

Abstract The polymerization of 1,4‐benzenediboronic acid (BDBA) on mica to form a covalent organic framework (COF‐1) reveals a dramatic increase in crystallinity when physically confined by exfoliated graphene. COF‐1 domains formed under graphene confinement are highly geometric in shape and on the order of square micrometers in size, while outside of the exfoliated flakes, the COF‐1 does not exhibit long‐range mesoscale structural order, according to atomic force microscopy imaging. Micro‐Fourier transform infrared spectroscopy confirms the presence of COF‐1 both outside and underneath the exfoliated graphene flakes, and density functional theory calculations predict that higher mobility and self‐assembly are not causes of this higher degree of crystallinity for the confined COF‐1 domains. The most likely origin of the confined COF‐1's substantial increase in crystallinity is from enhanced dynamic covalent crystallization due to the water confined beneath the graphene flake. 

Abstract Nanoelectrochemistry allows for the investigation of the interaction of per‐ and polyfluoroalkyl substances (PFASs) with silver nanoparticles (AgNPs) and the elucidation of the binding behaviour of PFASs to nanoscale surfaces with high sensitivity. Mechanistic studies supported by single particle collision electrochemistry (SPCE), spectroscopic and density functional theory (DFT) calculations indicate the capability of polyfluorooctane sulfonic acid (PFOS), a representative PFAS, to selectively bind and induce aggregation of AgNPs. Single‐particle measurements provide identification of the “discrete” AgNPs agglomeration (e.g. 2–3 NPs) formed through the inter‐particles F−F interactions and the selective replacement of the citrate stabilizer by the sulfonate of the PFOS. Such interactions are characteristic only for long chain PFAS (‐SO₃⁻) providing a means to selectively identify these substances down to ppt levels. Measuring and understanding the interactions of PFAS at nanoscale surfaces are crucial for designing ultrasensitive methods for detection and for modelling and predicting their interaction in the environment. 

Abstract The collisionless nature of planetary magnetospheres means that electromagnetic forces are fundamental in controlling the flow of energy and momentum through these systems. We use Pioneer Venus Orbiter (PVO) observations to demonstrate that the magnetic pumping process can be active at Venus, in analogy to its recent discovery at Mars. The presented case study demonstrates the framework for how the process can work at Venus, and the results of a statistical analysis show that the ambient plasma conditions support the process being active. Magnetic pumping enables low frequency magnetosonic waves to heat ambient ionospheric electrons and provides a mechanism that couples the solar wind to the Venusian ionosphere. This is the first time the magnetic pumping process has been discussed at Venus. 

Abstract Gold screen printed electrodes (Au‐SPEs) were treated electrochemically to produce a micro‐rough pattern increasing the real electrode surface. The procedure based on the Dynamic Hydrogen Bubble Template (DHBT) method included electrochemical deposition of Au layers onto the surface of the Au‐SPEs, followed by a reductive process at −3 V (vs. Ag/AgCl) leading to formation of H₂bubbles, which produced pores in the Au multilayer. The morphology of the micro‐porous Au electrode was characterized by scanning electron microscopy (SEM), surface mapping, surface profilometry, and confocal microscopy. The electrode surface morphology was controlled by the time of the electrode reductive treatment (H₂evolution) and the optimized condition resulting in the best surface structuring was found. Notably, the surface roughness leading to the highest electrode surface area was significantly increased compared to previously reported results with Au‐SPEs.