Good Antifouling Research Articles

Metal-organic framework self-cleaning membrane enhanced water purification based on collaborative separation and photocatalysis process

The existence of membrane contamination will not only affect the flux and rejection of the membrane, but also greatly reduce the service life of the membrane. Therefore, the coupling of photocatalytic Metal-organic frameworks (MOFs) with separation membrane to prepare catalytic self-cleaning membrane can effectively alleviate membrane pollution and maintain membrane flux and rejection. The challenge of photocatalytic self-cleaning membrane treatment of organic wastewater is how to ensure a stable catalyst load while maintaining a high membrane flux, rejection and cycle life. In this paper, the heterojunction photocatalyst NH2-MIL-125@MIL-88B constructed based on the MOF-on-MOF principle was supported on Polyethersulfone (PES) substrate membrane by vacuum filtration method. Then, polyacrylic acid (PAA) and chitosan (CTS) are adhered to the loading side through a co crosslinking reaction, introducing PAA@CTS layer. The PAA@CTS layer not only improves the load stability of the photocatalyst but also enhances the hydrophilicity of the self-cleaning membrane in collaboration with the photocatalyst. The construction of the self-cleaning membrane further increases its flux without affecting the rejection of the base membrane, breaking the tradeoff between permeability and rejection. The rejection of the best self-cleaning membrane was 96.6 %, and the flux was 58.4 L·m−2·h−1. In the treatment process of simulated antibiotic wastewater, the flux recovery rate (FRR) of M-2 is as high as 98 %, and the irreversible fouling ratio (Rir) is only 1 %, which proves its good antifouling properties and stability, and is expected to be used for efficient treatment of antibiotic wastewater.

Mixed dimensional assembly of biodegradable and antifouling wood-based covalent organic framework composite membranes for rapid and efficient dye/salt separation

Manipulating materials of different dimensions into heterogeneous nanofiltration membranes with unique physicochemical properties and molecular sieving channels provides an effective way for accurate and fast molecular separation. Here we introduce a heterogeneous structure hybrid connection strategy to fabricate biodegradable wood-based covalent organic framework (COF) composite membranes. As a proof of concept, 3D Picea jezoensis (Siebold & Zucc.) Carrière was selected as the substrate of the membrane and in situ growth of 2D iCOF selective layers. Effective modulation of iCOF layers by 1D sulfonated polyaryletherketone (SPEEK-Na) using the “needle and thread” method. The rearrangement of the above multidimensional materials formed charge-regulated properties of laminar nano-channels and smooth hydrophilic contact area, thereby endowing specific molecular transport pathways and sieving capability for efficient dye/salt separation under ultra-low pressure of 0.5 bar. The wood-based heterostructured membranes exhibited high dye rejection (>97 %), low salt rejection (<10 %), and high permeance (172.34 L m−2 h−1 bar−1), which is superior to many reported dye/salt separation membrane materials. In addition, the system exhibited a certain degree of operational stability, good antifouling, and soil biodegradability. Overall, this work enables the design and fabrication of heterostructured separation membranes to be obtained from nature and used in nature, resulting in efficient and sustainable water purification applications.

Low MWCO non-polyamide nanofiltration membranes synthesized in aqueous by coupling with catechol-amine chemistry and the oxidation-induced self-polymerization of m-phenylenediamine

Catechol-amine coatings offer versatile routes for surface modifications and nanofiltration (NF) membrane preparations. However, the formation of the selective layer is time-consuming and often deficient, rendering it unsuitable for large-scale applications. In this work, oxidation-induced self-polymerization and catechol-amine chemistry were combined to rapidly construct nanofiltration membranes in an aqueous medium. M-phenylenediamine (MPD) underwent oxidation and self-polymerized on a polysulfone (PSF) support. The addition of sodium periodate facilitated the subsequent tannic acid (TA) coating. The catechol-amine reaction between oxidized TA and poly-MPD forms crosslinked poly TA-MPD complexes, offering the resulting membrane a high selectivity. The role of NaIO4 in the selective layer formation and the influences of the synthesis parameters on the membrane performance were discussed. Utilizing the facile method enabled the achievement of a low molecular weight cut-off (MWCO) NF membrane (180 Da). The membrane exhibited a high water permeance (10.9 Lm−2h−1bar−1) and good salt rejections (93 % for Na2SO4). The filtration of the bovine serum acid (BSA) solution demonstrated the membrane has good antifouling performance with a flux recovery ratio (FRR) of 95.1 %. The proposed method offers a straightforward and rapid approach to fabricating low MWCO NF membranes in an aqueous medium, which has potential in large-scale applications.

Organic–Inorganic Composite Antifouling Coatings with Complementary Bioactive Effects

Traditional antifouling coatings are toxic to marine life, which makes developing new environmentally friendly marine antifouling coatings imperative. Antifouling coatings that are nonadhesive and antimicrobial may provide an effective approach to achieving this goal. In this study, an organic–inorganic composite coating consisting of fluorinated polyurethane (FPU) and carboxymethyl chitosan–zinc oxide (CMC–ZnO) was prepared to achieve antifouling. The coating took advantage of the complementary bioactive effects of the low surface energy of FPU and the antimicrobial properties of CMC–ZnO. The coating showed good antifouling performance, with a survival rate for Escherichia coli of 3.15% and that for Staphylococcus aureus of 3.97% and an anti-protein adsorption rate of more than 90%. This study provides a simple method for preparing antifouling coatings using nonpolluting raw materials with minimal adverse effects on marine environments.

An antifouling electrochemical aptasensor based on a Y-shaped peptide for tetracycline detection in milk

Nonspecific adsorption of non-target components (especially proteins) in food matrix on sensing surfaces deteriorates accuracy and sensitivity of electrochemical sensors, which is a key challenge for food safety sensing. Therefore, electrochemical sensors with antifouling capability of high-protein food matrices are highly desired. In this paper, an efficient and simple antifouling electrochemical aptasensor for tetracycline (TC) analysis was constructed based on a self-designed Y-shaped peptide [CPPPPEK-(RSERSERSE)2] consisting of cysteine as the anchoring segment, polyproline as the supporting segment, and -EK-(RSERSERSE)2 as antifouling branches. Hydrophilic and electrically neutral amino acid sequence and Y-shaped space structure of the peptide endow the sensing surface with good antifouling performance in protein solutions and diluted milk. Under optimized experiment conditions, the proposed aptasensor can detect TC with a wide linear range (0.01–100 ng mL−1) and a limit of detection of 5.3 pg mL−1 (S/N = 3). The spiked recovery experiments confirmed high accuracy of the aptasensor in diluted milk without other pretreatments (recoveries: 90.96%–95.86%). This strategy offers a valid way to reduce matrix interference, showing a promise to be extended to other sensing systems for different targets.

Antifouling and smart covalent organic framework composite nanofiltration membranes with light-gated molecular transport

Covalent organic framework (COF) holds great promise in affording precise and fast molecular separation. Inspired by the light-gated channels in cell membranes, we developed artificial light-gated molecular channel composite membranes by vacuum filtration COF with azobenzene (AZO) functional groups. The simple stimuli response could remotely adjust the membranes separation performance. The cis membranes with off state under ultraviolet (UV) light have higher dye rejection than trans membranes with on-state channels. The permeance of composite membranes increased from 19.56 to ∼ 42.30 L h−1 m−2 bar−1, dye (Rose Bengal (RB)) rejection increased from 94.40 % to 99.12 % after 10 min of 365 nm UV irradiation. In addition, the composite nanofiltration membranes exhibited good antifouling performance due to hydrophilic and highly smooth surface. By controlling the trans-to-cis AZO isomerization via UV /visible (Vis) light, the solvent permeance and dye rejection can be dynamically tuned due to the adjustable pore size.

Composite membranes from bio-inspired catechol-amine coatings for pervaporation desalination

Compared with reverse osmosis, pervaporation is less influenced by the osmosis pressure of the feed solution, which endows it as an attractive desalination technology. Many researches focus on developing high-performance pervaporation desalination membranes. Bio-inspired polyphenol coatings are versatile tools for engineering membrane surfaces. Here, catechol-amine chemistry was the first time applied to construct dense composite pervaporation desalination membranes via a stepwise coating method. Tannic acid (TA) and polyethyleneimine (PEI) were chosen as typical materials. Fabrication parameters, including TA and PEI concentrations in the coating solution, pH, and thermal annealing, are crucial to the desalination performance of the resulting membranes. The TA-PEI interactions were studied by the UV–Vis absorption spectroscopy method. The membrane prepared at optimal conditions exhibits excellent desalination performance. The water flux was 43 kg/(m2·h) at 50 °C for the feed of 3.5 wt% NaCl solution (95 kg/(m2·h) at 70 °C). The intrinsic hydrophilicity of the selective layer material ensures the membrane processes of good antifouling performance. This work demonstrates the possibility and potential of applying bio-inspired catechol-amine chemistry to prepare pervaporation desalination membranes.

Tannic acid etched ZIF-8 incorporated thin-film nanocomposite nanofiltration membrane with enhanced performance

Incorporating functionalized nanomaterials in the selective layer of conventional polyamide nanofiltration (NF) membrane is a promising strategy for overcoming the trade-off between permeability and selectivity. Highly hydrodispersible TA/ZIF-8 composite nanomaterials were prepared by etching ZIF-8 with tannic acid, and the thin-film nanocomposite (TFN) NF membranes were prepared by introducing TA/ZIF-8 into the interfacial polymerization aqueous phase solution. The nanomaterials and NF membranes' structure, chemical composition, and hydrophilicity were comprehensively characterized. The influence and mechanism of introducing TA/ZIF-8 into the polyamide layer on the separation performance of the TFN membranes were discussed by separating typical mono- and divalent salts. The optimal TFN membrane had a water flux of 26.59 LMH-bar−1 (increased by 86.6% than that of the TFC-blank membrane) with 94.95% rejection of Na2SO4 while having good antifouling performance and stability. Furthermore, the inverse size exclusion phenomenon of chlorine-contained salts was explored through relevant control experiments. This work is valuable for expanding the application of 3D nanomaterials in membrane separation technology and preparing high-performance TFN nanofiltration membranes.

Preparation and application of the thermo-/pH−/ ion-sensitive semi-IPN hydrogel based on chitosan

Chitosan based hydrogels with multiple stimulus responses have broad application prospects in many fields. Considering the advantages of semi interpenetrating network (IPN) technology and the special temperature and ion responsiveness of polymers containing zwitterionic groups, a semi-IPN hydrogel was prepared through in situ free radical polymerization of N,N-dimethyl acrylamide and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide with polyethylene glycol dimethacrylate as a crosslinker and carboxymethyl chitosan as filler. The gel mass fraction and swelling ratio were measured, and the preparation conditions were optimized. The result indicated that the hydrogel possessed a unique thermo-/pH−/ ion-sensitive behavior. The swelling ratio increased with the increase of temperature and ion concentration, and showed a decreasing trend with the increase in pH. In addition, the hydrogel was stable when the stimuli changed. Adsorption behavior of the hydrogel to Eosin Y (EY) was systematically investigated. The adsorption process can be described well by the pseudo-second-order kinetic model and Langmuir isotherm model, indicating that it was a chemical adsorption. The experiments indicated that the hydrogel exhibited good antifouling and reusability features. Therefore, the semi-IPN hydrogel with antifouling properties and thermo-/pH−/ion-sensitivity can be easily manufactured is expected to find applications in water treatment fields.

Preparation of acrylic metal salt resin containing capsaicin derivative structure and study of anti-fouling properties

Modifications of acrylic resins with environmentally friendly compounds often solve the problems of marine fouling. In this work, capsaicin derivatives-modified acrylic acid resins were successfully synthesized via free radical polymerization and condensation reactions of monomeric acrylic acid, capsaicin derivatives, metal salts and benzoic acid and structurally characterized by infrared spectroscopy and nuclear magnetism. The physicochemical properties of the synthesized resin coatings were tested with a rotary viscometer, gel permeation chromatography, video optical contact angle measurements and a laser confocal tester. The self-polishing and antifouling properties of the resins were investigated with dynamic simulation experiments, algae inhibitions, bacterial inhibition experiments and real sea antifouling experiments. By comparing with the acrylic resin without capsaicin derivatives, the acrylic resin with added capsaicin derivatives had good antifouling performance, and the optimal content was 2.5 %. In summary, the capsaicin derivative-modified acrylic metal salt resins have good self-polishing properties and antifouling properties.

Structure and performance of polyvinylchloride microfiltration membranes improved by green silicon oxide nanoparticles for oil-in-water emulsion separation

Oil-in-water (O/W) emulsion separation has received wide attention in the field of industrial water treatment. Mixed matrix polyvinylchloride (PVC) membranes containing 0.1–1.5 wt% silicon oxide (SiO2) as an inorganic additive obtained from two different sources were fabricated via the phase inversion method. The impact of embedding SiO2 in the PVC texture was studied by making a comparison between SiO2 nanoparticles prepared from common water reeds as a bio-source (namely bio SiO2) and commercial SiO2. The fabricated membranes were characterized via Fourier-transform infrared spectroscopy, field emission scanning electron microscope, and atomic force microscopy. Also, the water contact angle and water flux were measured. The results of the water contact angle revealed that modification of the PVC membrane by 0.5 wt% bio SiO2 reduced the contact angle from 82.3° for the neat PVC membrane to 29.7° showing that high enhancement in the membrane's hydrophilicity. The effect of oil feed concentrations (100–1000 mg/L) and temperature (25, 35, and 45 °C) on the treatment efficiency and permeate flux was investigated at trans-membrane pressures (1.5, 2.5, and 3.5 bar). The results showed that the permeation flux of the modified membranes was higher than that of the neat membrane due to enhancing the membrane's properties. Finally, the membranes were evaluated in a crossflow system with simulated O/W emulsion as a feed. The bio SiO2/PVC membranes have applicable potential in the oily wastewater treatment for their low price, good antifouling performance, and high removal efficiencies of NTU (over 98.15 %), COD (up to 99.19 %) for a membrane containing 0.5 wt% bio SiO2 used for 100 mg/L O/W emulsion.

Regulating water flux of loose nanofiltration membrane by dopamine and cellulose nanocrystals for enhanced dye/salt separation

Nanofiltration (NF) membranes are widely used for dye and salt separation, however, a dense NF membrane is generally formed during interfacial polymerization, inducing low permeability of the membrane. Herein, a loose structure of the NF was prepared and regulated by additional other components, such as dopamine (DA) and carboxylated cellulose nanocrystal (C-CNC) through changing the interactions between water and oil phases. The results show that C-CNC not only improves hydrophilicity of the separation layer, but also controls the layer smooth and loose. The obtained membrane with suitable loose structure exhibits high water permeance (37.5 L m−2 h−1 bar−1) and rejection (above 99 %) for dyes including methyl blue (MB), congo red (CR) and direct red 80 (DR80). Additionally, it exhibits low rejection towards NaCl (∼10 %) and Na2SO4 (∼14 %), but good dye/salt separation factor of 451. The as-fabricated membrane is proved to have long-term stability, chlorine resistance and tolerance towards complex conditions (such as wide pH range, high temperature and composite separation system). The membrane shows good antifouling performance as well. Over all, the prepared membrane is promising for practical applications in textile effluent treatment, resources recycle and molecular separation.

A highly antifouling and eco-friendly hydrogel coating based on capsaicin derivative -functionalized polymer

Antifouling hydrogels have received extensive attention in the field of marine antifouling due to their excellent hydrophilicity and environmental friendliness. However, the antifouling applications of traditional hydrogels are limited by their poor antibacterial properties, and capsaicin derivatives, as nontoxic and environmentally friendly antifoulants, can be used to improve the antibacterial properties of hydrogels. From the perspective of practical application, hydrogels were obtained by crosslinking the copolymer of the capsaicin derivative N,N'-((4,5,6-trihydroxy-1,3-phenylene) bis (methylene)) diacrylamide (TPA), lipophilic monomers and hydrophilic monomers. This hydrogel exhibited anti-protein performance due to its hydrophilicity, and the capsaicin derivative caused the hydrogel coating to exhibit excellent algae inhibition performance (the minimum adhesion density of diatoms on the surface of the hydrogel coating was less than 440 cells/mm2), better algae anti-adhesion abilities than hydrogel reported in the other paper, and antibacterial effects (the antibacterial rate was more than 95%). After 73 d of panel testing in a real marine environment, there was still a good antifouling effect in the hydrogel coating. Hence, the antifouling performance was improved significantly by capsaicin derivative (TPA)-functionalized hydrogel coating. A new strategy is provided in this study for the preparation of hydrogels with superior marine antifouling properties.

Dynamic migration mechanism of borneol synergistic polyethylene glycol for the construction of silicon-acrylate antifouling coating

Silicone-based coatings are vulnerable to marine fouling organisms in static environments, which seriously hampers its practical application. Here, an amphiphilic acrylate polymer is designed by hydrophilic polyethylene glycol and antibacterial borneol, which is introduced into polydimethylsiloxane (PDMS) by covalent linking to prepare antifouling coatings. XPS and CA tests prove that amphiphilic acrylate polymer can migrate to coating surface in the marine environment to maximize antifouling properties. Mytilus edulis foot protein adhesion test find it can weaken interface force between Mefp-3 and surface. Laboratory antifouling performance evaluations confirm that the coatings are effective against the adhesion of bacteria (86.72 % reduction for E. coli), diatoms (87.76 % reduction for Nitzschia closterium). The good antifouling properties of coatings are ascribed to the synergistic effect among unique bicyclic monoterpene structure of natural non-toxic borneol and amphiphilic acrylate polymer on surface of coatings. Moreover, the coating is less harmful to the marine ecological balance than traditional coatings containing toxic biocides due to the introduction of natural non-toxic borneol. This work contributes new insights in the exploration of environmentally friendly coating with excellent static antifouling performance.

Immobilization of nano-Cu on ceramic membrane by dopamine assisted flowing synthesis for enhanced catalysis

Catalytic membranes containing metal nano-catalysts are effective in removing organic pollutants from wastewater. The relative low catalytic activity of the non-noble metals (such as Cu nanoparticles) presents a challenge for their widespread application. Herein, Cu nanoparticles were in-situ immobilized on ceramic substrate by a dopamine assisted flowing synthesis method to strengthen its catalytic property. Firstly, a precursor solution containing dopamine and Cu2+ was cyclically permeated through the ceramic microfiltration substrate to form a polydopamine coating with chelated Cu2+. Then, Cu nanoparticles were in-situ formed with the aid of NaBH4. FESEM, EDS, XPS and XRD analyses demonstrate the successful formation of the Cu nanoparticles. The obtained membrane depicts good hydrophilicity and permeability (556.51 L m-2h−1 at 0.1 MPa). In the continuous catalytic degradation under cross-flow filtration mode, the membrane achieves 90.84 % reduction of 4-nitrophenol (4-NP) and 92.36 % degradation rate of methyl orange (MO). The large amount of Cu nanoparticles immobilized within the membrane pores (form inner-pore microreactors) enhance the catalytic activity of the membrane, resulting in an apparent reaction rate constant of 38.78 min−1 on the permeation side. The composite membrane has good antifouling and easy-cleaning properties (the flux recovery rate is 84.3 %). In long-term experiments, the catalytic degradation rate of MO remains above 96 % throughout 50 cycles, demonstrating good stability. This study provides a novel strategy for developing catalytic membrane with immobilized non-noble metal nanoparticles, which has potential applications in environmental remediation.

Assessment of marine antifouling property of fluoropolymer nanocomposite coating on steel substrate ‐ A preliminary assay in laboratory

AbstractThis paper presents the results of immersion assay on antifouling performance of a fluoropolymer nanocomposite coating on the steel substrate using natural seawater medium in laboratory. The fluoropolymer nanocomposite coating was composed in the presence of reinforcement additives, including organically modified titanium dioxide (m‐TiO2), organically modified zirconium dioxide nanoparticles (m‐ZrO2) and antifouling agent of Cu2O nanoparticles and fluoropolymer. The ratio of m‐TiO2/m‐ZrO2/Cu2O was fixed at 2/2/5 wt.% in comparison with the fluoropolymer weight. The immersion test was applied to evaluating the antifouling performance of the nanocomposite coating in the natural seawater and has been carried out in dynamic condition at the room temperature of 30 ± 0.1 oC during 60 days of testing. The change in characteristics of the nanocomposite coating was observed and recorded weekly including contact angle, color of coating and the released Cu ions content. Other characteristics such as infrared spectroscopy, surface morphology, abrasion resistance and adhesion of the nanocomposite coating were analyzed before and after testing. The obtained results showed that Cu ions could release with a low rate from the nanocomposite coating when rising immersion time and the release of Cu ions followed a linear equation. The contact angle and gloss of the coating were slightly reduced during testing period, indicating that the smoothness of the coating surface did not change significantly when immersed in natural seawater. The adhesion and abrasion resistance of the coating were almost unchanged after 60‐day testing. In summary, the nanocomposite coating has good antifouling performance when immersion under natural seawater in the laboratory, considering the above specific characteristics, including the synergistic effect of reinforcement fillers (m‐TiO2, m‐ZrO2 nanoparticles) and antifouling agent (Cu2O nanoparticles) in the polymer matrix. This in‐lab experiment in natural seawater medium has confirmed the nanocomposite coating's antifouling performance and facilitated practical deployment.

Broad-Spectrum Clearance of Lipopolysaccharides from Blood Based on a Hemocompatible Dihistidine Polymer.

Blood infection can release toxic bacterial lipopolysaccharides (LPSs) into bloodstream, trigger a series of inflammatory reactions, and eventually lead to multiple organ dysfunction, irreversible shock, and even death, which seriously threatens human life and health. Herein, a functional block copolymer with excellent hemocompatibility is proposed to enable broad-spectrum clearance of LPSs from whole blood blindly before pathogen identification, facilitating timely rescue from sepsis. A dipeptide ligand of histidine-histidine (HH) was designed as the LPS binding unit, and poly[(trimethylamine N-oxide)-co-(histidine-histidine)], a functional block copolymer combining the LPS ligand of HH and a zwitterionic antifouling unit of trimethylamine N-oxide (TMAO), was then designed by reversible addition-fragmentation chain transfer (RAFT) polymerization. The functional polymer achieved effective clearance of LPSs from solutions and whole blood in a broad-spectrum manner and had good antifouling and anti-interference properties and hemocompatibility. The proposed functional dihistidine polymer provides a novel strategy for achieving broad-spectrum clearance of LPSs, with potential applications in clinical blood purification.

An Injectable and Antifouling Supramolecular Polymer Hydrogel with Microenvironment-Regulatory Function to Prevent Peritendinous Adhesion and Promote Tendon Repair.

The imbalance of extrinsic and intrinsic healing of tendon is thought to be the main cause of peritendinous adhesions. In this work, we prepare an injectable supramolecular poly(N-(2-hydroxypropyl) acrylamide) (PHPAm) hydrogel merely via side chain hydrogen-bonding crosslinks. This PHPAm exhibits good antifouling and self-healing properties. The supramolecular hydrogel simultaneously loaded with Prussian blue (PB) nanoparticles and platelet lysate (PL) is exlpored as a functional physical barrier, which could significantly resist the adhesion of fibrin and fibroblasts, attenuate the local inflammatory response, and enhance the tenocytes activity, thus balancing extrinsic and intrinsic healing. The PHPAm hydrogel is shown to prevent peritendinous adhesions considerably by inhibiting NF-κB inflammatory pathway and TGF-β1/Smad3-mediated fibrosis pathway, thereby significantly improving tendon repair by releasing bioactive factors to regulate the tenocytes behavior. This work provides a new strategy for developing physical barriers to prevent peritendinous adhesions and promote tissue repair effectively. This article is protected by copyright. All rights reserved.

Construction of tannic acid-Fe complex coated PVDF membrane via simple spraying method for oil/water emulsion separation

Here, a polyvinylidene difluoride composite membrane (PVDF@TA–Fe membrane) was prepared via the repeated spraying of tannic acid (TA) and Fe3+ to form a TA–Fe complex on the hydrophobic PVDF membrane, which endows the membrane surface superhydrophilicity. The effects of the number of sprays on the surface wettability and emulsion separation capacity of membrane were systematically investigated. It was found that the TA-Fe(III)-complex network formed on the membrane significantly increased the hydrophilicity of the membrane, and the PVDF@TA–Fe membrane was found to exhibit superhydrophilicity/underwater superoleophobicity. The PVDF@TA–Fe membrane was found to exhibit good separation efficiencies (above 99%) and high fluxes (1189.1–2310.0 L m−2 h −1 bar−1) when used to separate oil and water in various oil/water emulsions. The repeated separation experiments show that the membrane has a good antifouling performance and maintains a good oil/water separation performance after more than 10 cycles. The present work is of great importance to the large-scale preparation of superhydrophilic membranes and treatment of oily wastewater.

Copolymerization of zwitterionic sulfobetaine and hydrophobic acrylamide based antifouling electrochemical biosensors for detection of CA125 in clinical serum samples

It is crucial to construct antifouling electrochemical biosensors with long-term stability and high sensitivity for the detection of biomarkers in complex biological environments to prevent the unspecific adsorption of proteins and other biomolecules. Herein, a glassy carbon electrode electropolymerization with polyaniline (PANI/GCE) was further modified with a copolymerization (PSN) of zwitterionic sulfobetaine methacrylate (SBMA) and hydrophobic N-isopropyl acrylamide (NIPAM) by simple hydrophobic interaction to construct an antifouling biosensor. PSN forms a stable self-assembled monolayer on the PANI/GCE surface and exhibits good antifouling performance in serum due to the advantages of hydrophobic anchoring and the antifouling performance of zwitterionic polymers. Ascribe to the large specific surface area and excellent conductivity, the present biosensor can detect CA125 in undiluted samples in the range of 0.01–1000 U mL−1 with a limit of detection of 2.7 mU mL−1 (3σ/k). Both with good biocompatibility and biological stability, PSN modified sensing surface realizes a long-term antifouling for 15 days in a buffer solution. The present work provides a simple strategy for the direct analysis of CA125 in human serum without a complicated construction of biosensors, indicating the potential application in clinical diagnosis.