Nanoporous Surface Research Articles

The Gaseous Hydrogen Transport Capacity in Nanopores Coupling Bulk Flow Mechanisms and Surface Diffusion: Integration of Profession and Innovation

Due to its unique chemical structure, hydrogen energy inherently has a high calorific value without reinforcing global warming, so it is expected to be a promising alternative energy source in the future. In this work, we focus on nanoconfined hydrogen flow performance, a critical issue in terms of geological hydrogen storage. For nanopores where the pore scale is comparable to hydrogen’s molecular size, the impact on hydrogen molecules exerted by the pore surface cannot be neglected, leading to the molecules near the surface gaining mobility and slipping on the surface. Furthermore, hydrogen adsorption takes place in the nanopores, and the way the adsorption molecules move is completely different from the bulk molecules. Hence, the frequently applied Navier–Stokes equation, based on the no-slip boundary condition and overlooking the contribution of the adsorption molecules, fails to precisely predict the hydrogen flow capacity in nanopores. In this paper, hydrogen molecules are classified as bulk molecules and adsorption molecules, and then models for the bulk hydrogen and the adsorption hydrogen are developed separately. In detail, the bulk hydrogen model considers the slip boundary and rarefaction effect characterized by the Knudsen number, while the flow of the adsorption hydrogen is driven by a chemical potential gradient, which is a function of pressure and the essential adsorption capacity. Subsequently, a general model for the hydrogen flow in nanopores is established through weight superposition of the bulk hydrogen flow as well as the adsorption hydrogen, and the key weight coefficients are determined according to the volume proportion of the identified area. The results indicate that (a) the surface diffusion of the adsorption molecules dominates the hydrogen flow capacity inside nanopores with a pore size of less than 5 nm; (b) improving the pressure benefits the bulk hydrogen flow and plays a detrimental role in reducing surface diffusion at a relatively large pressure range; (c) the nanoconfined hydrogen flow conductance with a strong adsorption capacity (PL = 2 MPa) could reach a value ten times greater than that with a weak adsorption capacity (PL = 10 MPa). This research provides a profound framework for exploring hydrogen flow behavior in ultra-tight strata related to adsorption phenomena.

Effect of micro-/nano-porous thin film surfaces prepared by a hybrid method of etching and electrochemical deposition on pool boiling heat transfer performance

Surfaces created using efficient and inexpensive methods are highly demanded in industrial applications of extremely high temperatures. In this study, Composite Nano-particle Coated Over CuO Filmed (CNCCF) surface is prepared through two processes, first through chemical etching to produce a thin film of CuO over bare Cu surface, and secondly deposition of Ni-Al2O3 composite nano-particle over CuO thin filmed copper surface by electrochemical deposition process. The completed CNCCF surface exhibits favorable characteristics for improved boiling heat transmission, such as wettability, roughness, porosity, etc. An experiment on pool boiling is conducted on the CNCCF and bare Cu surface. DI water at atmospheric pressure is used as the boiling fluid. Findings show that the CNCCF surface exhibits enhanced Critical Heat Flux (CHF) and Boiling heat Transfer Coefficient (BHTC) than bare Cu surface. The increased porosity, roughness, and other properties of the CNCCF surface are the cause of this improvement in CHF and BHTC. A high-speed camera is also used to monitor and analyze bubble behavior during boiling on all surfaces, including the Bare Cu. Further evidence for the enhancement of boiling heat transfer on the CNCCF surface comes from the nucleation site density, departure diameter, and frequency characteristics of bubbles.

Mechanisms of carbon dioxide extracting oil at the boundary layer on shale nanopore surface: insights from molecular dynamics

Boundary layer formed by crude oil on the shale nanopores surface hinders fluidity of crude oil and leads to a decline in oil recovery. CO2 injection has been considered as an effective method to enhance shale oil recovery. However, the impact of CO2 on the disruption of boundary layers within shale nanopores and the extraction mechanisms of crude oil during the recovery process remains unclear. In this work, molecular dynamics simulation was employed to investigate the process of using scCO2 to extract crude oil from shale nanopore surface. During the process of scCO2 extraction, polar molecules have the capability to reduce the diffusion coefficient, prolong the residence time, and decrease flowability of decane, ultimately resulting in a deterioration of its kinetic properties. Phenol, with its hydrophilic hydroxyl group, closely adheres to the shale surface, while the oleophylic benzene ring covers the shale surface, causing a transition in the wettability of this segment from hydrophilic to oleophylic. As a result, a substantial adsorption of decane occurs on phenol. The research findings contribute to the comprehension of the scCO2 extraction mechanism and the advancement of unconventional oil and gas resources.

Orientational Pathways during Protein Translocation through Polymer-Modified Nanopores.

Protein translocation through nanopores holds significant promise for applications in biotechnology, biomolecular analysis, and medicine. However, the interpretation of signals generated by the translocation of the protein remains challenging. In this way, it is crucial to gain a comprehensive understanding on how macromolecules translocate through a nanopore and to identify what are the critical parameters that govern the process. In this study, we investigate the interplay between protein charge regulation, orientation, and nanopore surface modifications using a theoretical framework that allows us to explicitly take into account the acid-base reactions of the titrable amino acids in the proteins and in the polyelectrolytes grafted to the nanopore surface. Our goal is to thoroughly characterize the translocation process of different proteins (GFP, β-lactoglobulin, lysozyme, and RNase) through nanopores modified with weak polyacids. Our calculations show that the charge regulation mechanism exerts a profound effect on the translocation process. The pH-dependent interactions between proteins and charged polymers within the nanopore lead to diverse free energy landscapes with barriers, wells, and flat regions dictating translocation efficiency. Comparison of different proteins allows us to identify the significance of protein isoelectric point, size, and morphology in the translocation behavior. Taking advantage of these insights, we propose pH-responsive nanopores that can load proteins at one pH and release them at another, offering opportunities for controlled protein delivery, separation, and sensing applications.

A molecular level-based parametric study on the capture of hydrogen sulfide and carbon oxides from flue gas mixtures using Au nanopores

ABSTRACT Identifying a means of effectively separating and adsorbing the harmful constituents from flue gas emissions is always crucial for the protection of human health and the environment. All-atom molecular dynamics were employed to analyze the dynamic behaviour of flue gas molecules in Au nanopores. The influences of various system temperatures, gas concentrations, and pore sizes on the adsorption conformation, diffusion coefficient, average adsorption energy, and adsorption probability of the flue gases inside an Au nanopore were examined. Results showed that when the temperature rose to 300∼400 K, the gaseous H2S constituent in the flue gas was swiftly adsorbed to the nanopore walls due to the strong H2S-Au interactions, enabling an effective separation of H2S from the flue gas. In addition, increases in pore size (d ≥ 40 Å) reduced the adsorption probability of CO2 and CO on the nanopore surfaces, which also promoted constituent separations of H2S from the flue gas. When the concentration of flue gas exceeded 6.6 mol/L, hydrogen bonds of H2O clusters and their networks entangled, impeding molecular diffusion and thereby reducing the functionality of nanopore-trapping molecules. The results presented in this paper provide a valuable reference for filter material design for flue gas depuration.

Enhanced Cellular Uptake through Nanotopography‐Induced Macropinocytosis

AbstractEfficient cellular uptake of biomolecules, including genetic material, mRNA, proteins, and nanoparticles, requires novel approaches to overcome inherent cellular barriers. Here, the study investigates how nanotopographical cues from nanoporous surfaces impact the uptake efficiency by cells. The results demonstrate notable enhancements in cellular uptake efficiency across a range of vectors when cells are exposed to nanoporous surfaces. The uptake process is found to be dependent on the size and morphology of the nanopores, reaching a peak efficacy with blind pores of 400 nm in size. Enhanced genetic transduction on nanoporous surfaces are observed for multiple vectors, including lentiviruses, baculoviruses, and mRNA molecules. The versatile nature of this approach allows co‐transfection of cells with multiple mRNA vectors. Moreover, the nanoporous platform is used for efficient and fast manufacturing of Chimeric Antigen Receptor (CAR)‐T cells through lentiviral transduction. Furthermore, the study pinpoints macropinocytosis as the predominant mechanism driving increased cellular uptake induced by the nanoporous surfaces. The introduced method for enhancing genetic transduction of cells has applications in immunotherapy research, drug delivery, and cell engineering.

Elaeis guineensis Jacq.waste-derived as an supercapacitor electrode material with low cost and environmentally friendly

The increasingly rapid development of environmentally friendly porous activated carbon (AC) materials has attracted the attention of researchers. Moreover, the material can be produced from organic waste which is abundantly available. This time, porous active carbon based on green material (palm frond waste) has been successfully prepared and characterized. The application of more efficient, environmentally friendly and cost-effective, methods and production instrument has been optimized in this research. Integrated pyrolysis with carbonization (N2; 600 °C) and physical activation (H2O; 800 °C) produces activated carbon with a high purity level of up to 80 %. Through reviewing N2 gas absorption, it was confirmed that palm frond AC has a specific surface area of 356 m2 g−1, with a rough morphological structure and very rich surface nanopores. Furthermore, XRD characterization confirmed the purity of carbon through good amorphorosity properties with the presence of two wide peaks at diffraction angles of 22-24° and 42-44°. These findings show that the development and innovation of activated carbon production that is more environmentally friendly and cost-effective from palm frond waste is capable of producing active carbon with extraordinary physical characteristics. This palm tree AC has high potential for developing applications such as as an absorption material in air purifiers and water purifiers. Apart from that, these extraordinary characteristics also make palm frond AC suitable for use as electrode material in components of energy storage devices, supercapacitors with specific capacitance 86 F g−1.

Anodic Oxidation of 3D Printed Ti6Al4V Scaffold Surfaces: In Vitro Studies

This study focuses on the surface modification of Ti6Al4V scaffolds produced through additive manufacturing using the Powder-Bed Fusion Electron-Beam Melting (PBF-EB) technique. From our perspective, this technique has the potential to enhance implant osseointegration, involving the growth of a layer of titanium dioxide nanotubes (TiO2) on surfaces through anodic oxidation. Scaffolds with anodized surfaces were characterized, and the formation of a nanoporous and crystalline TiO2 layer was confirmed. The analysis of cell morphology revealed that cells adhered to the anodized surfaces through their filopodia, which led to proliferation during the initial hours. However, it was observed that the adhesion of Saos-2 cells was lower on anodized scaffolds compared to both built and chemically polished scaffolds throughout the cell culture period. The results obtained here suggest that while anodic oxidation is effective in achieving a nanoporous surface, cell adhesion and interaction were affected by the weak adhesion of cell filopodia to the surface. Thus, combining surface treatment techniques to create micro- and nanopores may be an effective alternative for achieving a favorable cellular response when the objective is to enhance the performance of porous titanium scaffolds in the short term.

Enhancing Solar-Driven Water Purification by Multiscale Biomimetic Evaporators Featuring Lamellar MoS2/GO Heterojunctions.

Solar-powered steam generation holds a strong sustainability in facing the global water crisis, while the production efficiency and antifouling performance remain challenges. Inspired by river moss, a multiscale biomimetic evaporator is designed, where the key photothermal conversion film composed of lamellar MoS2/graphene oxides (GO) can significantly enhance the evaporation efficiency and solve the problem of fouling. First-level leaf-like MoS2/GO nanosheets, obtained by a modified hydrothermal synthesis with an assisted magnetic-field rotation stirring, are self-assembled into a second-level nanoporous film, which achieves an evaporation rate (ER) of 1.69 kg m-2 h-1 under 1 sun illumination and an excellent self-cleaning ability. The tertiary-bionic evaporator with a macroscopic crownlike shape further enhances the ER to 3.20 kg m-2 h-1, 189% above that of planar film, yielding 20.25 kg m2 of freshwater from seawater during a daytime exposure of 6 h. The exceptional outcomes originate from the macroscopic biomimetic design and the microscopic integration of heterojunction interfaces between the MoS2 and GO interlayers and the nanoporous surface. The biomimetic evaporator indicates a potential direction through surface/interface regulation of photothermal nanomaterials for water desalination.

Short-Time Magnetron Sputtering for the Development of Carbon-Palladium Nanocomposites.

In recent nanomaterials research, combining nanoporous carbons with metallic nanoparticles, like palladium (Pd), has emerged as a focus due to their potential in energy, environmental and biomedical fields. This study presents a novel approach for synthesizing Pd-decorated carbons using magnetron sputter deposition. This method allows for the functionalization of nanoporous carbon surfaces with Pd nano-sized islands, creating metal-carbon nanocomposites through brief deposition times of up to 15 s. The present research utilized direct current magnetron sputtering to deposit Pd islands on a flexible activated carbon cloth substrate. The surface chemistry, microstructure, morphology and pore structure were analyzed using a variety of material characterization techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, gas sorption analysis and scanning electron microscopy. The results showed Pd islands of varying sizes distributed across the cloth's carbon fibers, achieving high-purity surface modifications without the use of chemicals. The synthesis method preserves the nanoporous structure of the carbon cloth substrate while adding functional Pd islands, which could be potentially useful in emerging fields like hydrogen storage, fuel cells and biosensors. This approach demonstrates the possibility of creating high-quality metal-carbon composites using a simple, clean and economical method, expanding the possibilities for future nanomaterial-based applications.

Nanoscale Insights into CO2 Enhanced Shale Gas Recovery in Gas-Water Coexisting Kerogen Nanopores.

The presence of water clusters in kerogen nanopores reduces the occurrence and migration of methane (CH4) and thus affects shale gas extraction. CO2 injection, as an effective approach to enhance shale gas recovery, still presents challenges in its ability to mitigate the impact of immobile water clusters within the kerogen. In this work, molecular dynamics simulations were employed to investigate the microscopic transport process of water clusters and CH4 following CO2 injection in the gas-water coexisting kerogen nanopores. The results demonstrate that CO2 can desorb irreducible water clusters to dredge the pores while extracting CH4, enhancing gas-water mobility, and shale gas recovery by transitioning the wettability of the kerogen nanopore surface from weakly water-wet to CO2-wet. The impact of CO2 on the wettability of kerogen surfaces is primarily manifested in two aspects: CO2 can intrude the interface between water clusters and kerogen to reduce the number of hydrogen bonds between them, resulting in the detachment of water clusters; and the surface of kerogen nanopores can form a layer of CO2 gas film, which prevents desorbed water clusters and CH4 from readsorbing onto the wall surface. This study provides important insights in enhancing the understanding of the microscopic mechanisms in nanoscale flow, as well as for the development of an unconventional gas reservoir.

Induced Formation of Plasma Membrane Protrusions with Porous Materials as Instructive Surfaces.

The plasma membrane is a vital component in cellular processes, and its structure has a significant impact on cellular behavior. The physical characteristics of the extracellular environment, along with the presence of surface pores, can influence the formation of membrane protrusions. Nanoporous surfaces have demonstrated their capacity to induce membrane protrusions in both adherent and non-adherent cells. This chapter presents a methodology that utilizes a nanoporous substrate with nanotopographical constraints to effectively stimulate the formation of membrane protrusions in cells.

Nanopore sensing specific enhancement technique for single molecule detection

Nanopore sensors have become important tools for analyzing biomarkers, including but not limited to nucleic acids, proteins, and other biomolecules that play important roles in life. Though the nanopores themselves have no selectivity towards target molecules, higher sensitivity of nanopore sensing to the target biomarkers could be achieved with the help of the specificity enhancement technology. In this work, the basic principles of nanopore sensing are first introduced, then methods of modifying nanopore surface as well as the development and application of those selectivity enhancement technologies of nanopore sensing in recent years are reviewed. These enhancement technologies primarily fall into two categories: surface functionalization and molecular probes. Surface functionalization is further categorized based on the types of functional molecules used, while molecular probes are classified according to carrier forms. Finally, in this paper several challenges that nanopore sensing continues to encounter are discussed and some suggestions are made for its future development.

Zeolitic imidazolate framework-8 encapsulated with Mo-based polyoxometalates as surfaces with antibacterial activity against Escherichia coli.

Bacterial infections represent a major global health concern, causing millions of deaths and a significant economic burden. The development of antibacterial nanoporous surfaces with potential mechano-bactericidal effects can revolutionize infection control practices. In this study, a hybrid material of zeolitic imidazolate framework-8 (ZIF-8) doped with phosphomolybdic acid (PMA) was synthesized and characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and N2 sorption isotherms. PMA@ZIF-8 performance as an antibacterial agent against E. coli was superior to that of its individual constituents, suggesting a synergistic effect of PMA and ZIF-8. The incorporation of PMA into ZIF-8 significantly enhanced its antibacterial efficacy, as evidenced by a twofold reduction in MIC (375 μg mL-1 vs. 750 μg mL-1) and a 4.35 times increase in the bactericidal kinetics rate constant. The time-kill curve experiment revealed that PMA@ZIF-8 achieved a 3-log reduction within 7 hours, whereas ZIF-8 required 24 hours to reach the same level of reduction. The density functional theory (DFT) calculated bandgap of PMA@ZIF-8 was significantly less than that of ZIF-8. Also, PMA@ZIF-8 has caused the elimination of 56.72% of the thiol group as detected by Ellman's assay. Accordingly, PMA@ZIF-8 can be both computationally and experimentally demonstrated as an oxidative nanozyme. PMA@ZIF-8's surface topology revealed nanorod protrusions, suggesting a potential mechano-bactericidal effect, which was confirmed by live/dead assay on PMA@ZIF-8-coated glass. This study highlights the potential of the PMA@ZIF-8 hybrid as a highly effective antibacterial agent, holding promise for creating multifunctional antibacterial surfaces.

Surface Roughness Effects on Confined Nanoscale Transport of Ions and Biomolecules.

Biological channels, especially membrane proteins, play a crucial role in metabolism, facilitating the transport of nutrients and other materials across cell membranes in a bio-electrolyte environment. Artificial nanopores are employed to study ion and biomolecule transport behavior inside. While the non-specific interaction between the nanopore surface and transport targets has garnered significant attention, the impact of surface roughness is overlooked. In this study, Nanopores with different levels of inner surface roughness is created by adjusting the FIB (Focus Ion Beam) fabrication parameters. Experiments and molecular dynamics (MD) simulations are employed to demonstrate that greater roughness results from larger FIB beam currents and shorter processing times. Lower roughness increases the capture rate of biomolecules, while greater roughness enhances the normalized blockade current (ΔI/I0 ). The phenomenon of rougher nanopores are attributed to a barrier-dominated capture mechanism and more likely to induce DNA folding. This transport barrier exists in rough nanopores by utilizing steer molecular dynamics (SMD) simulations to investigate the force profile of a dA10 DNA molecule during translocation is demonstrated. This work illustrates how surface roughness influences the ionic current features and the translocation of biomolecules, paving a new way for tunning the molecule transport in nanopores.

Modeling and Validation of Assisted Cold Start for a PEMFC Coupled to a Thermochemical Preheater

Cold start from sub-zero temperatures poses a challenge for automotive application of polymer electrolyte fuel cells (PEMFC), as product water freezes inside the cells hereby endangering operation safety. Therefore, ice formation in the cathode pores has to be avoided by preheating of the fuel cell above sub-zero temperatures. The concepts for such assisted cold start can be divided into internal and external heating strategies [1]. Amongst the latter, especially thermochemical preheating by metal hydrides presents a compelling yet efficient technology, as the heat is provided by exothermal hydrogen absorption without consumption of additional external energy.In this work, assisted PEMFC cold start is simulated with the transient 2D numerical model for a single fuel cell thermally coupled to a thermochemical preheater via a coolant fluid developed by Gießgen and Jahnke [2]. Here, the numerical model is validated against cold start experiments of the coupled system for both cell behavior and thermal balance of the heat transfer fluid. Starting from an initial temperature of -5°C, fuel cell behavior is then studied for 300 s of open circuit voltage (OCV) followed by a current density ramp up to 0.33 A/cm² in 150 s and a subsequent constant current period up to 500 s. Model validation is done with respect to temperature and voltage evolution as well as the energy balance of the coupled system. When the cold start is unassisted, a significant voltage drop down to 0.6 V is observed to occur already at 0.22 A/cm² and thus before reaching the maximum current density by the end of the ramp. Whereas difficult to deduce from experiments, this intermediate voltage drop can be linked to massive ice formation blocking up to 87% of the cathode catalyst pores, eventually causing a significant decrease of the electrochemically active surface (ECSA). For this ECSA reduction, an exponential dependence on the ice saturation is identified, suggesting that initial ice nucleation primarily occurs on the macroporous catalyst surface, thereby blocking the nanoporous surfaces of the primary particles within. When the cold start is assisted, a preheating phase of 41 s is performed prior to the current ramp. As the metal hydride reactor effectively heats up the heat transfer fluid, the fuel cell temperature in turn raises rapidly above the freezing point in less than 20 s. Consequently, ice formation is observed to be effectively reduced to saturations of less than 1%. As a result of this assisted cold start, the voltage drop is significantly attenuated and a minimum voltage of 0.65 V is now reached for a maximum of 0.33 A/cm² only at the end of the current ramp.

Investigation of Manufacturing Process Related Structure and Performance of the Fuel Cell Electrode Thanks to Small Angle Neutron Scattering

With climate change and fossil fuel sustainability concerns faced globally, proton exchange membrane fuel cell (PEMFC) based electric vehicles have been recognized as a promising alternative. However, large-scale commercialization requires progress in performance, cost and durability, for which the electrode (catalyst layer) is the limiting component. The electrode is composed of nanoparticles of platinum (Pt) catalyst on a carbon (C) support, embedded in a proton conductive polymer (ionomer). It is obtained from a slurry (catalyst ink) after evaporating solvent consisting of a water and alcohol mixture. The structural properties of the slurry, including the ionomer and carbon dispersions, catalyst aggregation and ionomer coverage onto the Pt/C composite strongly influence the performance and durability of the final electrode. Nevertheless, currently little is known of these structures, particularly with regards to the dispersion of the ionomer component onto the surface of porous carbon, despite the fact it is now established that it plays a crucial role in the operation of the fuel cell. The lack of information leaves research and development to be heavily reliant on a trial and error basis. Developing a detailed understanding of the dispersion and its correlation to fuel cell performance is key in advancing the PEMFC electrode.However, the heterogeneous nature of these inks, with only short-range order observed on both micro- and nano- scales, makes them difficult to study by conventional laboratory techniques. Small angle neutron scattering (SANS) has been identified as a suitable method for the study of the electrodes as it is not hindered by the ink opacity as in optical techniques (commonly used to study dispersions) and allows to probe the bulk structures in the 1-100 nm scale relevant for each component. In particular, contrast variation (CV) SANS exhibits a major advantage in studying such complex systems, where scattering signal from multiple components can be deconvoluted by matching the scattering length density of the solvent to that of a desired component. Nevertheless, data on the ink itself is missing and it has only been investigated in a handful of studies by SANS.1-3 Shibayama et al.1 proposed a structural model of Pt/C aggregates coated by an ionomer shell in a water-based ink. Yoshimune et al.2 demonstrated that the amount of Pt on the carbon surface alters the thickness and density of said ionomer layer. Harada et al.3 were able to distinguish adsorbed and deposited ionomer on the composite surface as well as quantize their distribution.Yet although ink composition is known to impact the dispersion greatly, no systematic investigation linking its many variables has been conducted. For example, the ionomer will conform differently in a water/alcohol solvent used commercially in contrast to a water-based one. The porosity of the carbon support will impact distribution of Pt on its surface as well as the degree of ionomer penetration into the support. Additionally, although the fundamental understanding of the ink structure is imperative, it has seldom been further linked to the performance of the electrode itself.Therefore, the aim of this project is to utilize CV-SANS to study the impact of each catalyst ink component on the structure of the dispersion, and their relation to each other, through altering only a single variable at a time. The variables include the components as well as their proportions, such as the carbon concentration or the ionomer to carbon ratio. The performance of the electrode manufactured from said ink compositions will then be evaluated using electrochemical studies. Recently we performed CV-SANS studies on the ink, investigating the extent of ionomer adsorption on the Pt/C composite as a function of both carbon type and presence of Pt in the system. Both carbon supports studied, high surface area carbon with surface nano-pores accessible to the ionomer, and graphitized carbon, which has high internal porosity, yet inaccessible to the ionomer, pose an interest in industrial applications. Indeed, from these preliminary results it is evident platinum plays a significant role in the ink structure, particularly in the case of graphitized carbon (figure 1). The ink system will be quantitatively characterized using a singular value decomposition method already employed in literature to give insight into parameters such as the amount of ionomer adsorbed onto the carbon surface or the structure of the layer. References 1 M. Shibayama, T. Matsunaga, T. Kusano, K. Amemiya, N. Kobayashi and T. Yoshida, J Appl Polym Sci, , DOI:10.1002/app.39842.2 W. Yoshimune and M. Harada, https://doi.org/10.1246/cl.190017, 2019, 48, 487–490.3 M. Harada, S. I. Takata, H. Iwase, S. Kajiya, H. Kadoura and T. Kanaya, ACS Omega, 2021, 6, 15257–15263. Figure 1

Nanopore surface engineering of molecular imprinted mesoporous organosilica for rapid and selective detection of L-thyroxine

To develop a biosensing platform for precise diagnosis and management of thyroid-related diseases, the sensitive and selective recognition and identification of L-thyroxine (T4), a thyroid hormone, remains challenging. We herein introduce T4-imprinted mesoporous organosilica (T4-IMO) for sensitive and specific detection of T4 via the sophisticated engineering of pore surfaces using additives with different polarities. The pore surface of T4-IMO emitting a stable fluorescence signal is simply modified by fixed additives. Additives embedded in the pore surface promote the rebinding response of T4 into the recognized cavities, subsequently sensitizing T4 detection. Notably, T4-IMO containing abundant fluorine elements on the pore surface shows a high affinity toward T4, remarkably boosting the rebinding capacity. In addition to good selectivity to T4, the “turn-off” fluorescent signal exhibits a linear relationship with the logarithm of T4 concentration in a range of 0–500nM with a detection limit of 0.47nM in synthetic urine samples. Our findings can establish an insightful strategy for the rational design of molecular-recognition-based sensor systems for the selective and sensitive detection of target analytes.

Investigation of nanotopography on SOCE mediated cell migration via live-cell

The exploration of cell response to nanotopography has attracted considerable attentions for years. This article focuses on the influence of nanotopography on the intracellular Ca2+ dynamics, the most ubiquitous but ignored second messenger. The classic titanium nanotubes (NT) were fabricated by anodization to formulate nanoporous surfaces. Firstly, the store operative calcium entry (SOCE) in endoplasmic reticulum (ER) and functional Ca2+ release-activated Ca2+ (CRAC) channels were significantly enhanced on NT surfaces that revealed by live-cell Ca2+ imaging and fluorescence resonance energy transfer (FRET) identification of orai1-stim1 connection. To investigate the potential implication of Ca2+ elevation, the dynamic cell migration trajectory was monitored by a self-made holder, which could not only be suitable for the opaque implant surface but also guarantee the focus fields identical during samples shifting. The cell migration on NT surface was more vigorous and rapid, which was correlated with higher focal adhesion proteins expression, Ca2+-dependent calpain activity and stim1 level. In conclusion, this study has confirmed the novel ER Ca2+ hemostasis pathway on nanosurfaces and its crucial role in cell migration regulation, which may help for more biofavorable implant surface design.Graphical

Effect of dense packed micro-/nano-porous thin film surfaces developed by a combined method of etching, electrochemical deposition and sintering on pool boiling heat transfer performance

Effect of dense packed micro-/nano-porous thin film surfaces developed by a combined method of etching, electrochemical deposition and sintering on pool boiling heat transfer performance