Excellent Antifouling Performance Research Articles

Positively charged nanofiltration membranes with gradient structures for enhancing separation properties

Creating a gradient structure in a separation layer is an effective approach for enhancing separation performance of thin film composite membranes. Here we present the preparation of a positively charged nanofiltration membrane with a gradient structure. An inner layer consisting of a loose polyester separation layer with large pores was formed through the interfacial polymerization (IP) reaction between triethanolamine (TEA) and trimesoyl chloride (TMC). And a dense and thin top layer composed of a polyamide separation layer was obtained by secondary interfacial polymerization (SIP) reaction using polyethyleneimine (PEI) along with unreacted TMC and residual acyl chloride groups of IP reaction. The influences of TEA concentration, PEI concentration and SIP time on the physicochemical properties and separation performances of the membrane were systematically analyzed. Our results show that the presence of the gradient structure optimized mass transfer pathways and reduced mass transfer resistance, resulting in significantly improved permeability of 13.0 ± 0.5 L·m−2·h−1·bar−1 (over 3 times compared with control-PEI), high MgCl2 rejection of 91.7 ± 0.6 %, and an excellent stability and anti-fouling performance. Our work provides valuable insights and guidance for developing high-performance positively charged NF membrane with gradient structures.

Novel highly permeable ultrathin polyamide composite membrane with interfacial polymerization of 4,6-diaminoresorcinol for molecular separation

Developing ultrathin polyamide thin-film composite (PA TFC) membrane with ultrahigh performance to overcome the perm-selectivity upper bound of molecular separation is still the major challenge for practical applications. Herein, we first designed an ultrahigh performance PA TFC membrane fabricated by interfacial polymerization of 4,6-diaminoresorcinol dihydrochloride (DAR) and trimethyl chloride (TMC) on the substrate. The structural morphology of the PA active layer and the separation performance of the resultant membrane were tuned by DAR dosage. This ultrathin PA TFC membrane breaks the trade-off between water permeance and dye (NOM) selectivity. Accordingly, the optimal membrane had a water flux of 212.5 LHM/bar with superior rejection of 98.6 % and 100 % for BBR and CR, respectively, surpassing the upper-bound limit of most reported polymeric membranes thus far. The membranes also exhibited a high salt passage (>95 %), achieving an impressive screening capacity for the dye/salt mixture as well as excellent antifouling and operation stability performance. This work sheds light on the regulation of the PA selective layer via new amine monomer featuring ultrahigh performance.

Three-dimensional zwitterionic hydrogel-based evaporators with simultaneous ultrahigh evaporation rates and anti-fouling performance

Zwitterionic hydrogels (ZHs) are commonly adopted as evaporators to address the issues of low evaporation rate and poor salt resistance in solar-driven interfacial desalination due to their unique anti-polyelectrolyte (AP) effect. However, the inherent limitations of ZHs, including low water transfer rates compared to their evaporation rates and poor mechanical properties, have restricted their applications to two-dimensional (2D) evaporator configurations. Herein, we proposed a unique design of three-dimensional (3D) composite solar evaporators based on ZHs and polyvinyl alcohol (PVA) sponge to improve the water transfer capacity and mechanical properties of ZHs, and thus achieve ultrahigh evaporation rates and excellent anti-fouling performance. The porous structure and super hydrophilicity of PVA sponge endowed the prepared 5-cm-high ZH-based solar evaporators (ZHSE) with water transfer rates significantly faster than those without PVA sponge. In addition, the elastic PVA sponge component enhanced the mechanical properties of ZHSE, allowing it to easily fabricate 3D structures to obtain higher evaporation rates. Moreover, PVA sponge barely weakened the AP effect of poly(sulfobetaine methacrylate) (PSBMA) hydrogels in the ZHSE. Consequently, the evaporation rate of ZHSE reached 4.66kgm-2 h-1 at 3.5wt%, one of the highest among previous reports, attributed to the contributions from the 3D structural design of the evaporator and AP effect of ZHs. Meanwhile, ZHSE showed outstanding anti-fouling properties and excellent shape stability, working in 20wt% brine ten hours a day for ten consecutive days without noticeable salt deposition and volume shrinkage. This work provides a new route to design high-performance hydrogel-based evaporators with high water transfer rates.

The preparation of electrically-enhanced and hydrophilic CNTs-PVDF composite hollow fiber membranes for fouling resistance

The anaerobic membrane bioreactor has great potentials to treat the wastewater with high organic matter due to the efficient anaerobic digestion process and high biomass retention. However, the existence of membrane fouling significantly increases the maintenance cost, and always requires frequent and complex cleaning process to recover the membrane performance. Thus, it is significant to fabricate a membrane with excellent anti-fouling performance for the application in membrane bioreactors. Herein, we prepared the CNTs-PVDF hollow fiber membrane with fouling resistance via loading the conductive CNTs coating on the surface of commercial PVDF membrane by a simple cross-linking reaction with hydrophilic polyvinyl alcohol and succinic acid. “Dual defense” was constructed by the combination of the hydrophilic surface and conductive CNTs coating, which lifted the anti-fouling performance of this membrane. In the assistance of electrical effect, the permeance of the membrane with −1.2 V bias could be recovered to 95 % of original state by simple hydraulic cleaning, while that of the membrane without bias was only 58 % after filtrating the sludge of 2000 mg/L. Furthermore, this membrane also exhibited the superior stability and fouling resistance in the operation of anaerobic electrochemical membrane bioreactor, which was promising for the advanced water treatment.

Metal-phenolic network as precursor complex coating for forward osmosis membrane with enhanced antifouling property.

In this study, a multi-functional layer was developed based on the commercially available cellulose triacetate (CTA) forward osmosis (FO) membrane to improve its antifouling property. Tannic acid/ferric ion (TA/Fe3+) complexes were firstly coated as a precursor layer on the membrane surface via self-assembly. Afterwards, the tannic acid/diethylenetriamine (TA/DETA) hydrophilic functional layer was further coated, following Ag/polyvinylpyrrolidone (PVP) anti-bacterial layer was formed in situ through the reducibility of TA to obtain TA/Fe3+-TA/DETA-Ag/PVP-modified membrane. The optimized precursor layer was acquired by adjusting the buffer solution pH to 8, TA/Fe3+ ratio to 4 and the number of self-assembled layers to 5. The permeability testing results illustrated that the functional layer had an insignificant effect on the membrane transport parameters. The TA/Fe3+-TA/DETA-Ag/PVP-modified membrane simultaneously exhibited excellent physical and chemical stability. The coated membrane also demonstrated enhanced anti-bacterial properties, achieving 98.63 and 97.30% inhibition against Staphylococcus aureus and Escherichia coli, respectively. Furthermore, the dynamic fouling experiment showed a 12% higher water flux decrease for the TA/Fe3+-TA/DETA-Ag/PVP CTA membrane compared to the nascent CTA membrane, which proved its excellent antifouling performance. This work provides a feasible strategy to heighten the antifouling property of the CTA FO membrane.

Preparation of polyaniline conductive membranes through immersion of dopant solution for dye/salt separation

The preparation of conductive loose nanofiltration (NF) membranes for effective separation of dye/salt wastewater mixtures remains a great challenge. In the current study, a novel method of immersing the polyaniline (PANI) membrane in some organic salt solutions to dope PANI membrane was employed to prepare conductive PANI loose NF membranes. Three dopants with different molecular weight, poly (sodium 4-styrene sulfonate) (PSS), sodium dodecyl sulfate (SDS), and sodium dodecylbenzene sulfonate (SDBS), were chosen to prepare the doping solutions under neutral and acidic (pH = 0.5 in HCl) conditions. The neutrally doped PANI membranes all had lower pore size distribution, lower Zeta potential, and higher conductivity compared with the undoped PANI membrane; and these properties were further enhanced for the membranes doped under acidic condition. The PANI membrane doped by acidic PSS solution (PANI-PSS-HCl membrane) had a pore size of 1.7 nm and a pure water flux of 44.7 L·m−2·h−1, and exhibited a rejection of over 99.9 % for eriochrome black T, acid fuchsin, congo red, and sunset yellow in the dye solutions, whereas less than 5 % for NaCl solution, which was suitable for dye/salt separation due to the large molecular size of PSS. When PANI-PSS-HCl membrane was used as the cathode, the membrane exhibited excellent anti-fouling performance with increased external voltage due to enhancement of electrostatic repulsion force between the anionic dyes and the surface of the conductive membrane. This work provides a simple and reliable method to prepare conductive loose NF membranes for effective separation of dye/salt wastewater with excellent anti-fouling performance under external voltage.

Cobalt single-atom catalyst tailored ceramic membrane for selective removal of emerging organic contaminants

Water reuse is an effective way to solve the issues of current wastewater increments and water resource scarcity. Ultrafiltration, a promising method for water reuse, has the characteristics of low energy consumption, easy operation, and high adaptability to coupling with other water treatment processes. However, emerging organic contaminants (EOCs) in municipal wastewater cannot be effectively intercepted by ultrafiltration, which poses significant challenges to the effluent quality and sustainability of ultrafiltration process. Here, we develop a cobalt single-atom catalyst-tailored ceramic membrane (Co1-NCNT-CM) in conjunction with an activated peroxymonosulfate (PMS) system, achieving excellent EOCs degradation and anti-fouling performance. An interfacial reaction mechanism effectively mitigates membrane fouling through a repulsive interaction with natural organic matter. The generation of singlet oxygen at the Co-N3-C active sites through a catalytic pathway (PMS→PMS∗→OH∗→O∗→OO∗→1O2) exhibits selective oxidation of phenols and sulfonamides, achieving >90% removal rates. Our findings elucidate a multi-layered functional architecture within the Co1-NCNT-CM/PMS system, responsible for its superior performance in organic decontamination and membrane maintenance during secondary effluent treatment. It highlights the power of integrating Co1-NCNT-CM/PMS systems in advanced wastewater treatment frameworks, specifically for targeted EOCs removal, heralding a new direction for sustainable water management.

Bioinspired thermo-responsive membrane with hybrid micro/nanostructure for water gating and emulsion separation

Smart membranes with tunable wettability hold great promise for controllably oil/water mixtures separations, including oil-water mixtures and surfactant stability oil/water emulsions. Herein, a thermo-responsive membrane with bioinspired hybrid micro/nanostructure was constructed on commercial PVDF membrane, which exhibits excellent thermo-responsive performance and antifouling ability. In this process, the thermo-responsive polymer graft to membrane surface via thiol-ene click reaction, preserve the high interfacial roughness and excellent switching wettability between hydrophilicity/underwater oleophobicity at 25 °C and hydrophobicity at 50 °C. The membrane can be applied in various surfactant stability oil-in-water emulsions and water-in-oil emulsions, demonstrating high separation efficiency, recyclability for various kinds of emulsions. The hybrid micro/nanostructures render the membrane with excellent antifouling performance. The membranes show good potentials for smart liquid separation such as on-demand oil-spill cleanup, remote controllable operation of oil/water emulsion separation device.

Design of anti-fouling membranes via prebiotic chemistry-inspired aminomalononitrile (AMN) coating strategy: Aldehyde-mediated chemical immobilization of pseudo-zwitterionic compounds

Although zwitterionic polymers were extensively explored for anti-fouling surface modification, the resulting significant loss in membrane permeability is undesirable. Assisted by co-deposition of aminomalononitrile (AMN) and terephthalaldehyde (TA), in this study a high-performance membrane with low fouling propensity was designed via chemical immobilization of a novel pseudo-zwitterionic compound, namely 3-(dimethyl(3-((3-sulfonatopropyl)ammonio)propyl)ammonio)propane-1-sulfonate (DMPDA-QS), onto the polyethersulfone (PES) substrate. The optimal membrane showed high water permeance (∼366 L m−2 h−1 bar−1) and high rejection (>98.0 %) to model proteins. The immobilization of this pseudo-zwitterionic compound led to a nearly neutral surface and enhanced hydrophilicity, and the dynamic fouling experiments proved its excellent antifouling performance against both negatively (i.e., bovine serum albumin, BSA) and positively (i.e., lysozyme, LYZ) charged foulants with flux recovery of >93% and >88% after 3-cycle filtration, respectively. A mathematical model was used to quantify the contribution of mass transfer resistance caused by reversible and irreversible fouling, showing nearly unchanged resistance of the modified membranes in contrast with 260% increase of the pristine PES after 3 filtration cycles. The developed fabrication strategy provided a viable and versatile route for designing high-performance antifouling membranes.

Fabrication of dual functional marine antifouling coatings by infusing epoxy silicone oil modification of quaternary ammonium

Slippery liquid-infused porous surface (SLIPS) has attracted widespread attention in marine antifouling field, but it lacks the contact-killing ability, which limits its long-term anti-fouling efficiency. Herein, a SLIPS endowed with both resist and contact-killing antimicrobial performances is reported. Firstly, anodic aluminum oxides (AAO) with composite structures of the pores and pyramids were prepared and modified with siloxane. Then, a silicone oil containing quaternary ammonium salt (QAS-SO) groups was synthesized and infused into specially designed AAO, forming a QAS-SLIPS. The surface demonstrated remarkably anti-bacterial performances both Gram-positive Bacillus sp. and Gram-negative V. natriegens, and also maintained essential contact-killing antimicrobial activities from the grafted QAS groups. Biofouling testing suggested excellent antifouling performances of the QAS-SLIPS by declining the adhesion of 90.6 % Phaeodactylum tricornutum and 74.1 % of Chlorella pyrenoidosa. Overall, the antifouling performance of QAS-SLIPS comes primarily from two aspects, including physical isolation and contact-killing. Due to the easy of synthesis and excellent broad-spectrum antifouling effects, the QAS-SO could be potentially used for the development of antifouling coatings or as a lubricant for other devices.

Simple fabrication of electrochemical sensor based on integration of dual signal amplification by the supporting electrode and modified nanochannel array for direct and sensitive detection of vitamin B2.

Development of simple and reliable sensor for detecting vitamin content is of great significance for guiding human nutrition metabolism, overseeing the quality of food or drugs, and advancing the treatment of related diseases. In this work, a simple electrochemical sensor was conveniently fabricated by modification a carbon electrode with vertically-ordered mesoporous silica film (VMSF), enabling highly sensitive electrochemical detection of vitamin B2 (VB2) based on the dual enrichment of the analyte by the supporting electrode and nanochannels. The widely used glassy carbon electrode (GCE), was preactivated using simple electrochemical polarization, The resulting preactivated GCE (p-GCE) exhibited improved potential resolution ability and enhanced peak current of VB2. Stable modification of VMSF on p-GCE (VMSF/p-GCE) was achieved without introducing another binding layer. The dual enrichment effect of the supporting p-GCE and nanochannels facilitated sensitive detection of VB2, with a linear concentration ranged from 20 nM to 7 μM and from 7 μM to 20 μM. The limit of detection (LOD), determined based on a signal-to-noise ratio of three (S/N = 3), was found to be 11 nM. The modification of ultra-small nanochannels of VMSF endowed VMSF/p-GCE with excellent anti-interference and anti-fouling performance, along with high stability. The constructed sensor demonstrated the capability to achieve direct electrochemical detection of VB2 in turbid samples including milk and leachate of compound vitamin B tablet without the need for complex sample pretreatment. The fabricated electrochemical can be easily regenerated and has high reusability. The advantages of simple preparation, high detection performance, and good regeneration endow the constructed electrochemical sensor with great potential for direct detection of small molecule in complex samples.

Investigations into the antimicrobial behavior and cytotoxicity of purified detonation diamond nanoparticles and their assembled micro‐/nano‐structured films

Antimicrobial activity and cytotoxicity are significantly influenced by the type of carbon-based nanomaterials. To reveal the cellular behaviors of zero-dimensional (0D) diamond nanoparticles and their derivatives, the self-assembly technology was used to synthesize 2D micro‐/nano‐structured diamond film from single particles. The focused ion beam (FIB) lift-out method was conducted for Transmission Electron Microscopy (TEM) observation. This paper reported the antimicrobial performance of diamond nanoparticles and assembled diamond film against Gram-positive Bacillus sp. and Gram-negative E. coli as elucidated by characterizing the material-bacterial interaction behaviors. Diamond nanoparticle uptake by cells was visualized using TEM. Further biological testing of assembled micro‐/nano‐structured diamond films revealed the desirable biocompatibility and excellent anti-fouling performance against microbial adhesion and colonization. The presented results may contribute to the development of the manufacturing techniques and biological applications for micro‐/nano‐structured diamond films.

Enhanced adhesive and mechanically robust silicone-based coating with excellent marine anti-fouling and anti-corrosion performances.

Poly(dimethylsiloxane) (PDMS) is widely used in marine antifouling coatings due to its low surface energy property. However, certain drawbacks of PDMS coatings such as poor surface adhesion, weak mechanical properties, and inadequate static antifouling performance have hindered its practical applications. Herein, condensation polymerization is utilized to prepare PDMS-based polythiamine ester (PTUBAF) coatings that consist of PDMS, polytetrahydrofuran (PTMG), 2, 3, 5, 6-tetrafluoro-1, 4-benzenedimethanol (TBD) as the main chains and isobornyl acrylate(IBA) as the antifouling group. The surface adhesion to the substrate is enhanced due to the hydrogen bond between the coated carbamate group and the hydroxyl group on the surface of the substrate. Mechanical properties of PTUBAF are significantly improved due to the benzene ring and six-membered ring biphase hard structure. The strong synergistic effect of bactericidal groups and low surface energy surface endows the PTUBAF coating with outstanding antifouling performance. Due to the low surface energy surface, the PTUBAF coatings are also found to possess excellent anti-corrosion. Furthermore, since the PTUBAF coatings exhibit a visible light transmittance of 91 %, they can applied as protective films for smartphones. The proposed method has the potential to boost the production and practical applications of silicone-based coatings.

Hierarchical biocide-free silicone/graphene-silicon carbide nanocomposite coatings for marine antifouling and superhydrophobicity of ship hulls

A new series of fluorine-free, nonbiocidal, and hierarchical superhydrophobic silicone coatings filled with reduced graphene oxide (RGO)/β-SiC bamboo-like nanocomposites was successfully fabricated as durable ternary marine fouling release (FR) surfaces. RGO/β-SiC hybrid was used as coating nanofiller that would release fouling and confer surface robustness. It was facilely created using a straightforward one-phase ultrasonication technique. The dispersion of different concentrations of RGO sheets decorated with β-SiC bamboo-like fillers was determined to study the superhydrophobicity and antifouling behaviors of polysiloxane nanocomposites. RGO was prepared through a simple hydrothermal technique. Solution casting was used to distribute the RGO/β-SiC nanofillers throughout a silicone matrix. Atomic force microscopy, surface free energy, and water contact angle (WCA) were employed to examine the superhydrophobicity and micro/nanoroughness of the coatings. The mechanical, anticorrosive, and durability characteristics of the silicone-RGO/β-SiC-filled composites were also investigated. The antifouling effects of the coating systems were evaluated in the laboratory for 30 days with specific bacteria. The silicone-RGO/β-SiC (3 wt%) composite with the best dispersion, highest WCA (156°), and lowest surface free energy (12.7 mN/m) among the composites exhibited favorable FR characteristics. The well-dispersed PDMS-RGO/β-SiC (3 wt% nanofiller) composite presented the minimum degradation and cell viability percentages against Gram-positive and Gram-negative bacteria as well as diatoms. Therefore, this study produced a series of nonstick and fluorine-free ternary FR nanocomposites for maritime coatings with surface durability, superhydrophobicity, and fouling retardancy. This work highlights the design and preparation of multifunctional marine nanocoatings with excellent antifouling performance, easy applicability, and superhydrophobicity properties.

Small Channels Assembled by Multilayer ZIF-8 in Nanocomposite Membranes for Filtration of Ofloxacin in Water.

Metal-organic framework (MOF)-based hybrid membranes still face many unsolved difficulties in the field of liquid separation, with a reliable production technique standing out, in particular, for the water-stable MOF membranes. In this study, zeolitic imidazolate framework-8 (ZIF-8) with acceptable water stability, favorable polymer affinity, and high selectivity was meticulously grafted on commercial poly(vinylidene fluoride) (PVDF) via substrate carboxylation-assisted etching and then overlaid onto PVDF to fabricate a novel hybrid membrane by a layer-by-layer self-assembly method. The optimal membrane manufacturing conditions, including assembly time (10 min), Hmim/Zn2+ molar ratio (8:1), and optimal layer number (three layers), were thoroughly investigated for cutting-off ofloxacin in water filtration. Under low pressure, a nanofiltration scale permeability of about 199.2 L m-2 h-1 MPa-1 and 97.9% rejection of ofloxacin were obtained in bench-scale tests based on the synergistic effect of the Donnan effect and steric hindrance. More significantly, the resulting hybrid membrane demonstrated excellent hydrophilicity, high antifouling, and mechanical and repeatability performances, suggesting promising application possibilities in real-world wastewater filtering settings.

Construction of a Soft Antifouling PAA/PSBMA Hydrogel Coating with High Toughness and Low Swelling through the Dynamic Coordination Bonding Provided by Al(OH)3 Nanoparticles.

Marine biofouling, resulting from the adhesion of marine organisms to ship surfaces, has long been a significant issue in the maritime industry. In this paper, we focused on utilizing soft and hydrophilic hydrogels as a potential approach for antifouling (AF) coatings. Acrylic acid (AA) with a polyelectrolyte effect and N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine (SBMA) with an antipolyelectrolyte effect were selected as monomers. By adjusting the monomer ratio, we were able to create hydrogel coatings that exhibited low swelling ratio in both fresh water and seawater. The Al(OH)3 nanoparticle, as a physical cross-linker, provided better mechanical properties (higher tensile strength and larger elongation at break) than the chemical cross-linker through the dynamic coordination bonds and plentiful hydrogen bonds. Additionally, we incorporated trehalose into the hydrogel, enabling the repair of the hydrogel network through covalent-like hydrogen bonding. The zwitterion compound SBMA endowed the hydrogel with excellent AF performance. It was found that the highest SBMA content did not lead to the best antibacterial performance, as bacterial adhesion quantity was also influenced by the charge of the hydrogel. The hydrogel with appropriate SBMA content being close to electrical neutrality exhibits the strongest zwitterionic property of PSBMA chains, resulting in the best antibacterial adhesion performance. Furthermore, the pronounced hydrophilicity of SBMA enhanced the lubrication of the hydrogel surface, thereby reducing the friction resistance when applied to the hull surface during ship navigation.

2D vermiculite nanofiltration membrane with TiO2 nanoparticles as versatile intercalator for enhanced water purification

Two-dimensional (2D) materials membranes have gained widespread attention for their unique structure and outstanding separation performance. Herein, we developed a 2D vermiculite nanofiltration (TiO2@VMT) membrane using TiO2 nanoparticles as versatile intercalator. The interlayer spacing of vermiculite nanosheets was tuned from 1.352 ± 0.002 nm to 1.424 ± 0.004 nm. As a result, the optimized TiO2@VMT membrane exhibited high water flux of 261 L m−2 h−1, which was 14 times higher than that of vermiculite membrane, simultaneously showed excellent rejections (>98 %) for various organic dyes (molecular weight >374 g mol−1). Due to the photocatalytic degradation ability of TiO2 nanoparticles towards organic foulants, the TiO2@VMT membrane possessed excellent anti-fouling performance, with a flux recovery rate exceeding 90 % under UV radiation after three cycles of filtration experiment using oil-in-water emulsion and BSA solution as model foulants. Accordingly, our work may offer a possible route for the development of 2D nanofiltration membrane for efficient water purification.

A novel lotus-seedpod shaped separation membrane with efficient oil harvesting function for oil/water system

Facing the energy crisis and environmental problems, the technologies of harvesting oil from offshore oil spills are attracting worldwide attention. In the current study, a novel biomimetic acrylonitrile butadiene styrene (ABS) @ polyvinylidene fluoride (PVDF) -g- polyvinylpyrrolidone methacrylic acid (PMAA) membrane was constructed by the combination of three-dimensional (3D) printing and gamma-ray irradiation strategies. The prepared ABS@ PVDF-g-PMAA membrane presented a “lotus seedpod” shape. The water contact angle (WCA) of the membrane surface was decreased to 62.3°, which indicated hydrophilicity. The experimental data showed that the membrane displayed a flux of 22,413 L·m−2·h−1 and a harvesting efficiency of over 99 % from the oil/water mixture, which exceeded the previous literature. Moreover, the 10 cycles filtration tests verified the stability and antifouling ability of the membrane. Meanwhile, the membrane occupied a harvesting rate of 98.1 % and a flux of 9561 L·m−2·h−1 bar−1 for the oil/water emulsion system, exhibiting excellent filtration and anti-fouling performance after 5 cycles of filtration tests. This study not only supplied a novel biomimetic separation membrane but also pointed out a potential solution for offshore oil spills.

Low fouling electrochemical sensing interfaces based on Bovine serum albumin hydrogel for the detection of protein biomarkers in human serum

The development of electrochemical biosensor capable of detecting specific biomarkers in real complex biological samples remains a challenge significantly relevant to a range of disease diagnostic applications. Herein an antifouling electrochemical biosensor suitable for biomarker detection in human serum was constructed based on protein hydrogels. A typical protein bovine serum albumin (BSA) was crosslinked with glutaraldehyde to form a hydrogel, which was freeze-dried and re-swollen to exhibit excellent antifouling capability. The rheological testing revealed that the prepared BSA hydrogel possessed good elasticity with a critical strain value of about 600 %, which is important for the construction of stable hydrogel-based biosensors. Following the immobilization of CA125 antibodies onto the BSA hydrogel modified electrode, an electrochemical biosensor for the detection of CA125 was constructed, with a linear range of 0.1 ∼ 1000 U mL−1 and a limit of detection of 0.026 U mL−1. Owing to the unique properties of the BSA hydrogel, the biosensor exhibited good stability and excellent antifouling performances, and it was able to detect CA125 in human serum with acceptable accuracy. The strategy of constructing low fouling biosensors based on hydrogels prepared from BSA with biocompatibility and widespread availability represented a very promising advance along the road to develop biosensing devices with robust operation in complex biological fluids.

Novel polyamide-hydrazide based reverse osmosis membrane with enhanced antifouling properties

The typical “ridge-valley” structure of traditional reverse osmosis (RO) membranes ensures good permeability with high risk of inducing membrane fouling. It is a challenge to develop a smooth RO membrane without loss of permeability. In this study, cyclobutane-1,2,3,4-tetracarbohydrazide (CBTH) was designed and synthesized, and a composite RO membrane based on CBTH and cyclobutane-1,2,3,4-tetracarboxylic acid chloride (BTC) was constructed. The CBTH-BTC membrane exhibits a smooth selective layer with thickness of 45 nm. The desalination performance test results show that the CBTH-BTC membrane has permeability and desalination performance comparable to the traditional RO membrane (the water permeability coefficient reaches 3.0 L·m−2·h−1·bar−1, and the rejection of NaCl reaches 99.2 %). Importantly, the hydrophilic and smooth surface imparts the membrane with good antifouling properties to hydrophilic, hydrophobic and surfactant pollutants. In this study, RO membranes with good permeability and excellent antifouling performance were successfully prepared from the perspective of reaction monomer design, which provides a new idea to regulate the morphology and antifouling properties of RO membranes.