Airflow Triggered Water Film Self-Sculpturing on Femtosecond Laser-Induced Heterogeneously Wetted Micro/Nanostructured Surfaces.

Liquid manipulation is essential for daily life and modern industry, and it is widely used in various fields, including seawater desalination, microfluidic robots, and biomedical engineering. Nevertheless, the current research focuses on the manipulation of individual droplets. There are a few projects for water film management. Here, we proposed a facile method of wind-triggered water film self-sculpturing based on a heterogeneous wettability surface, which is achieved by the femtosecond laser direct writing technology and femtosecond laser deposition. Under the conditions of various airflow velocities and water film thicknesses, three distinct behaviors of the water film were analyzed. As a result, when the water film thickness is lower than 4.9 mm, the self-sculpture process will occur until the whole superhydrophobic surface dewetting. Four potential applications are demonstrated, including encryption, oil containers, reconfigurable patterning, and self-splitting devices. This work provides a new approach for manipulating a water film of fluid control engineering.

Magnetically Actuated Superhydrophilic Robot Sphere Fabricated by a Femtosecond Laser for Droplet Steering.

Droplet steering has important applications in biomedical detection, local chemical reactions, liquid collection, and microfluidic control. Presently, droplet steering methods typically require specific paths and can be challenging to operate, involving complex fabrications for the operating systems. Here, we show a magnetically actuated superhydrophilic robot sphere (MSR) based on femtosecond laser direct writing technology for droplet steering. Through femtosecond laser treatment, uniform micro-/nanostructures are constructed on the surface of a MSR. Additionally, the contactless magnetic actuator makes it possible to remotely steer the MSR to transport droplets. After preliminary exploration of the mechanism by which MSR drives the droplet movement, the ability of MSR to control the droplet movement was systematically tested and analyzed. Moreover, the applications of the MSR in complex path liquid collection and transport, three-dimensional space transport, self-cleaning, etc., are further verified. This strategy provides a novel and reliable path for droplet manipulation and broadens its application.

Bacterial surface attachment and fouling assay on polymer and carbon surfaces using Rheinheimera sp. identified using bacteria community analysis of brackish water.

Biofouling on surfaces in contact with sea- or brackish water can severely impact the function of devices like reverse osmosis modules. Single species laboratory assays are frequently used to test new low fouling materials. The choice of bacterial strain is guided by the natural population present in the application of interest and decides on the predictive power of the results. In this work, the analysis of the bacterial community present in brackish water from Mashabei Sadeh, Israel was performed and Rheinheimera sp. was detected as a prominent microorganism. A Rheinheimera strain was selected to establish a short-term accumulation assay to probe initial bacterial attachment as well as biofilm growth to determine the biofilm-inhibiting properties of coatings. Both assays were applied to model coatings, and technically relevant polymers including laser-induced graphene. This strategy might be applied to other water sources to better predict the fouling propensity of new coatings.

Grafted Polymer Coatings Enhance Fouling Inhibition by an Antimicrobial Peptide on Reverse Osmosis Membranes.

Bacterial biofilms that are formed on surfaces are highly detrimental to many areas of industry and medicine. Seawater desalination by reverse osmosis (RO) suffers from biofilm growth on the membranes (biofouling), which limits its widespread use because biofouling decreases water permeance and necessitates module cleaning and replacement, leading to increased economic and environmental costs. Antimicrobial peptides (AMPs) bound covalently to RO membranes inhibit biofilm growth and might delay membrane biofouling. Here we examined how various hydrophilic membrane coatings composed of zwitterionic, neutral, positively charged, and poly(ethylene glycol) (PEG)-grafted polymers affected the biocidal activity and the biofilm inhibition of a covalently bonded AMP on RO membranes. AMP magainin-2 was linked by the copper-catalyzed azide-alkyne cycloaddition reaction to a series of RO membranes that were grafted with different methacrylate polymers. Surface characterization by infrared spectroscopy, X-ray photoelectron spectroscopy, and water drop contact angle gave evidence of successful RO modifications, and zeta potential analysis reflected the increase in surface charge due to the linked, positively charged peptide. All AMP-modified membranes inhibited Pseudomonas aeruginosa growth compared to unmodified membranes, and the grafted methacrylic polymers did not significantly interfere with the peptide activity. On the other hand, membranes coated with zwitterionic and other acrylate polymers including AMP attachment inhibited biofilm growth more than either the AMP or the polymer coating alone. This enhancement led to ∼20% less biofilm biovolume on the membrane surfaces. The combination of antimicrobial coatings with polymer coatings known to resist fouling might aid future designs of surface coatings susceptible to biofilm growth.

Synergy on Surfaces: Anti-Biofouling Interfaces Using Surface-Attached Antimicrobial Peptides PGLa and Magainin-2.

The synergistic effect of antimicrobial compounds is an important phenomenon that can increase the potency of treatment and might be useful against the formation of biofilms on surfaces. A strong inhibition of microbial viability on surfaces can potentially delay the development of biofilms on treated surfaces, thereby enhancing the performance of water-purification technologies and medical devices, for example, to prevent hospital-acquired infections. However, the synergistic effects of surface-immobilized antimicrobial peptides (AMPs) have not yet been reported. Here, we demonstrate the synergistic antimicrobial effects of the AMPs PGLa and magainin-2 on modified reverse-osmosis (RO) membranes. These AMPs are known to act synergistically in the free state, but their antimicrobial synergistic effects have not yet been reported in a surface-immobilized state. The AMPs were functionalized with alkyne linkers and covalently attached to RO membranes modified with azides, using a click chemistry reaction. The resulting RO membranes showed reduced contact angles, indicating increased wettability. X-ray photoelectron spectroscopy confirmed the presence of the two peptides on the membranes via changes in the amounts of carbon, oxygen, and sulfur, which led to an increased S/C ratio, probably because of the sulfur present in the methionine residue of the peptides. The synergistic activity was measured with the free peptides in solution and covalently bound on RO membrane surfaces by observing increased leakage of 5(6)-carboxyfluorescein from large unilamellar vesicles. The synergistic antimicrobial activity against Pseudomonas aeruginosa was observed using surface-activity assays, where the AMP-modified RO membranes showed an effective inhibition of P. aeruginosa biofilm growth, as compared with unmodified membranes. An enhanced activity of antimicrobials on surfaces might lead to potent antimicrobial surfaces, which could result in more fouling-resistant water-treatment membranes.

Interfering with the Dimerization of the ErbB Receptors by Transmembrane Domain-Derived Peptides Inhibits Tumorigenic Growth in Vitro and in Vivo.

The ErbB family of tyrosine kinase receptors is a key element in preserving cell growth homeostasis. This family is comprised of four single-transmembrane domain proteins designated ErbB-1-4. Ligand binding initiates dimerization followed by tyrosine phosphorylation and signaling, which when uncontrolled lead to cancer. Accordingly, extensive research has been devoted to finding ErbB-intercepting agents, directed against ErbB-1 and ErbB-2, but so far, no inhibitor has targeted the transmembrane domain (TMD), which is instrumental for receptor dimerization and activation. Moreover, no antitumor agents targeted ErbB-3, which although it cannot generate signals in isolation, its heterodimerization with ErbB-2 leads to the most powerful and oncogenic signaling unit in the ErbB family. Here, to further elucidate the role of the interactions between the TMDs of the ErbB family in cancer, we investigated peptides derived from the TMDs of ErbB-1 and ErbB-2. We then focused on the C-terminal domains (B2C) and their analogue, named B2C-D, that contains both d- and l-amino acids. Both peptides incorporated the distal GXXXG dimerization motif to target the TMD of ErbB-3. Our results revealed that B2C-D is highly active both in vitro and in vivo. It significantly inhibits neuregulin- and EGF-induced ErbB activation, impedes the proliferation of a battery of human cancer cell lines, and retards tumor growth in vivo. Notably, combining low concentrations of B2C-D and gemcitabine chemotherapy completely arrested proliferation of pancreatic cancer cells. Biochemical and in vitro interaction studies suggest direct interference with the assembly of the wild-type ErbB-2-ErbB-3 heterodimer as the underlying mode of action. To the best of our knowledge, this is the first agent to target the TMDs of ErbB to delay tumor growth and signaling.

Assembly of the TLR2/6 transmembrane domains is essential for activation and is a target for prevention of sepsis.

TLR2, together with TLR1 and TLR6, is essential for detecting lipopeptides and bacterial cell wall components such as lipoteichoic acid from Gram-positive bacteria. In this study, we report that transmembrane domain (TMD)-derived peptides from TLR2 and TLR6 specifically inhibit TLR2 activation. Secretion of the cytokines TNF-α and IL-6 by cultured macrophages (RAW264.7 cell line) was inhibited by these peptides in response to TLR2 activation by lipoteichoic acid (TLR2/6 activator) or palmitoyl (3)-Cys-Ser-Lys(4)-OH (TLR2/1 activator) but not by LPS (TLR4 activator). Extensive biophysical and biochemical assays, combined with GALLEX experiments, show that these peptides heterodimerize with their complementary TMDs on their reciprocal protein. These results suggest that TLR2/6/1 TMD assembly is essential for activating this complex. Importantly, when administered to mice inflicted by TLR2, but not TLR4-driven lethal inflammation, a selected peptide rescued 60% of these septic mice, showing potent in vivo inhibition of TNF-α and IL-6 secretion. Furthermore, this peptide also showed high protection in a whole bacteria model. Owing to the importance of TLR2 regulation under a variety of pathological conditions, compounds that can fine-tune this activity are of great importance.

Development of Nontoxic Peptides for Lipopolysaccharide Neutralization and Sepsis Treatment.

Host defense peptides (HDPs), also named antimicrobial peptides (AMPs), are increasingly being recognized for serving multiple functions in protecting the host from infection and disease. Previous studies have shown that various HDPs can also neutralize lipopolysaccharide (LPS, endotoxin), as well as lipoteichoic acid (LTA), inducing macrophage activation. However, antimicrobial activity is usually accompanied by systemic toxicity which makes it difficult to use HDPs as antiendotoxin agents. Here we report that key parameters can uncouple these two functions yielding nontoxic peptides with potent LPS and LTA neutralization activities in vitro and in animal models. The data reveal that peptide length, the number, and the placement of positive charges are important parameters involved in LPS neutralization. Crucially, the peptide exhibited a separation between its membrane-disrupting and antimicrobial properties, effectively decoupling them from its ability to neutralize LPS. This essential distinction prevented systemic toxicity and led to the peptide's complete rescue of mice suffering from severe septic shock in two distinct models. Strong binding to LPS, changes in structure, and oligomerization state upon LPS binding were important factors that determined the activity of the peptides. In the face of the increasing threat of septic shock worldwide, it is crucial to grasp how we can neutralize harmful substances like LPS. This knowledge is vital for creating nontoxic treatments for sepsis.

Mass scale synthesis of graphene nanosheets using waste cardboard for application in perovskite solar cells and supercapacitors.

Advanced graphene-based materials have been proficiently incorporated into next-generation solar cells and supercapacitors because of their high electrical conductivity, large surface area, excellent charge-transport ability, and exceptional optical properties. Herein, we report the synthesis of graphene nanosheets (GNs) from waste cardboard via pyrolysis, with ethyl alcohol as the growth initiator. Additionally, we demonstrated the use of GNs in energy conversion and storage applications. Using the GN electrode in perovskite solar cells resulted in an excellent power conversion efficiency of ∼10.41 % for an active area of 1 cm2, indicating an enhancement of approximately 27 % compared to conventional electrodes. Furthermore, the GNs were used as active electrode materials in supercapacitors with excellent electrochemical performance and a high gravimetric specific capacitance of 167.5 F/g at a scan rate of 2 mV/s. The developed GNs can be efficiently used for energy storage, conversion, and electrochemical sensing applications.

Enhancing membrane disruption by targeting and multivalent presentation of antimicrobial peptides.

In order to enhance the membrane disruption of antimicrobial peptides both targeting and multivalent presentation approaches were explored. The antimicrobial peptides anoplin and temporin L were conjugated via click chemistry to vancomycin and to di- and tetravalent dendrimers. The vancomycin unit led to enhanced membrane disruption of large unilamellar vesicles (LUVs) displaying the vancomycin target lipid II, but only for temporin L and not for anoplin. The multivalent presentation led to enhanced LUV membrane disruption in the case of anoplin but not for temporin L.

Femtosecond laser-scribed superhydrophilic/superhydrophobic self-splitting patterns for one droplet multi-detection.

Superwettable patterned composite surfaces are being recognized as essential components in the field of precise droplet manipulation. However, developing simple and effective methods for manufacturing such surfaces remains a challenge especially for multi-detection surfaces. Here we present a femtosecond laser-based method to create a superhydrophobic/superhydrophilic (SHB/SHL) self-splitting pattern on a polyimide film to achieve droplet multi-detection. The mechanism behind droplet self-splitting on the SHB/SHL pattern surface is related to the dynamic behaviors of liquid recoiling and spreading. This behavior was affected by two main factors, including the width of the SHB stripe, and the radius of the SHL pattern. When the characteristic width is larger than 0.2, droplets are able to fully self-split. Furthermore, the SHB/SHL pattern can be utilized for alcohol detection and multiple biological tests performed using a single drop of biological fluid. This work provides a facile strategy for precise separation and distribution of microdroplets, and potentially could be applied in fluid recognition, biological screening, and combinatorial analysis.

A Laser-Induced Graphene-Titanium(IV) Oxide Composite for Adsorption Enhanced Photodegradation of Methyl Orange.

Numerous treatment methods such as biological digestion, chemical oxidation, and coagulation have been used to treat organic micropollutants. However, such wastewater treatment methods can be either inefficient, expensive, or environmentally unsound. Here, we embedded TiO2 nanoparticles in laser-induced graphene (LIG) and obtained a highly efficient photocatalyst composite with pollutant adsorption properties. TiO2 was added to LIG and lased to form a mixture of rutile and anatase TiO2 with a decreased band gap (2.90 ± 0.06 eV). The LIG/TiO2 composite adsorption and photodegradation properties were tested in solutions of a model pollutant, methyl orange (MO), and compared to the individual and mixed components. The adsorption capacity of the LIG/TiO2 composite was 92 mg/g using 80 mg/L MO, and together the adsorption and photocatalytic degradation resulted in 92.8% MO removal in 10 min. Adsorption enhanced photodegradation, and a synergy factor of 2.57 was seen. Understanding how LIG can modify metal oxide catalysts and how adsorption can enhance photocatalysis might lead to more effective pollutant removal and offer alternative treatment methods for polluted water.

Laser-Induced Graphene Capacitive Killing of Bacteria.

Laser-induced graphene (LIG) is a method of generating a foam-like conformal carbon layer of porous graphene on many types of carbon-based surfaces. This electrically conductive material has been shown to be useful in many applications including environmental technology and includes low fouling and antimicrobial surfaces and can address persistent environmental challenges spawned by bacterial and viral contaminates. Here, we show that a single film of LIG stores charge when an electrical current is applied and dissipates charge when the current is stopped, which results in electricidal surface antibacterial potency. The amount of accumulated and dissipated charge on a single strip of LIG was quantified with an electrometer by generating LIG on both sides of a nonconducting polyimide film, which showed up to 65 pC of charge when the distance between the surfaces was 94 µm corresponding to an areal capacitance of 1.63 pF/cm2. We further corroborate the stored charge decay of a single LIG strip with bacteria death via direct electrical contact. Antimicrobial rates decreased with the same monotonic pattern as the loss of charge from the LIG film (i.e., AR ∼ 97% 0 s after voltage source disconnection vs AR ∼ 21% 90 s after disconnection) showing bacterial death as a function of delayed LIG exposure time after applied voltage disconnection. In terms of energy efficiency, this translates to an increased bacteria potency of ∼170% for the equivalent energy costs as that previously estimated. Finally, we present a mechanistic explanation for the capacitive behavior and the electricidal effects for a single plate of LIG.

Multifunctional polyimide-based femtosecond laser micro/nanostructured films with triple Janus properties.

Flexible multifunctional composite films in which opposing surfaces have two or more distinct physical properties are highly applicable for wearable electronic devices, electrical power systems and biomedical engineering. However, fabrication of such "Janus" films can be time consuming, complex or economically not feasible. In this work, Janus polyimide (PI) films were prepared by femtosecond laser direct writing technology, which generated a honeycomb porous structure (HPS) on one side and a lawn-like structure (LLS) on the other. Deposition of silver nanowires (AGNWs) by drop coating on the LLS side (AGNWs@LLS) resulted in a film in which each face possessed highly distinct triple properties. The HPS side was superhydrophobic with a water contact angle (WCA) of ∼153.3° and electrically non-conductive, while the AGNWs@LLS side was superhydrophilic (WCA ∼7.8°) and highly conductive (∼3.8 Ω). Moreover, the AGNWs@LLS face showed ultra-low thermal radiation performance, almost reaching saturation. On a heating table at ∼100 °C, the temperature of the AGNWs@LLS side remained at ∼44.5 °C, while the HPS side exhibited a temperature of ∼93.9 °C. This "triple Janus film" and lasing techniques developed might be useful for designing new materials for the integration and miniaturization of multifunctional electronic equipment.

Ultrashort peptide bioconjugates are exclusively antifungal agents and synergize with cyclodextrin and amphotericin B.

Many natural broad-spectrum cationic antimicrobial peptides (AMPs) possess a general mode of action that is dependent on lipophilicity and charge. Modulating the lipophilicity of AMPs by the addition of a fatty acid has been an effective strategy to increase the lytic activity and can further broaden the spectrum of AMPs. However, lipophilic modifications that narrow the spectrum of activity and exclusively direct peptides to fungi are less common. Here, we show that short peptide sequences can be targeted to fungi with structured lipophilic biomolecules, such as vitamin E and cholesterol. The conjugates were active against Aspergillus fumigatus, Cryptococcus neoformans, and Candida albicans but not against bacteria and were observed to cause membrane perturbation by transmission electron microscopy and in membrane permeability studies. However, for C. albicans, selected compounds were effective without the perturbation of the cell membrane, and synergism was seen with a vitamin E conjugate and amphotericin B. Moreover, in combination with ß-cyclodextrin, antibacterial activity emerged in selected compounds. Biocompatibility for selected active compounds was tested in vitro and in vivo using toxicity assays on erythrocytes, macrophages, and mice. In vitro cytotoxicity experiments led to selective toxicity ratios (50% lethal concentration/MIC) of up to 64 for highly active antifungal compounds, and no in vivo murine toxicity was seen. Taken together, these results highlight the importance of the conjugated lipophilic structure and suggest that the modulation of other biologically relevant peptides with hydrophobic moieties, such as cholesterol and vitamin E, generate compounds with unique bioactivity.

Magnéli-Phase Ti4O7-Doped Laser-Induced Graphene Surfaces and Filters for Pollutant Degradation and Microorganism Removal.

Laser-induced graphene (LIG) has recently become a point of attraction globally as an environmentally friendly method to fabricate graphene foam in a single step using a CO2 laser. The electrical properties of LIG are studied in different environmental applications, such as bacterial inactivation, antibiofouling, and pollutant sensing. Furthermore, metal or nonmetal doping of graphene enhances its catalytical performance in pollutant degradation and decontamination. Magnéli phase (TinO2n-1) is a substoichiometric titanium oxide known for its high electrocatalytic behavior and chemical inertness and is being explored as a membrane or electrode material for environmental decontamination. Here, we show the fabrication and characterization of LIG-Magnéli-phase (Ti4O7) titanium suboxide composites as electrodes and filters on poly(ether sulfone). Unlike undoped LIG electrodes, the doped Ti4O7-LIG electrodes exhibit enhanced electrochemical activity, as demonstrated in electrochemical characterization using cyclic voltammetry and electrochemical impedance spectroscopy. Due to the in situ generation of hydroxyl radicals on the surface, the doped electrodes exhibit increase in methylene blue degradation and microorganism removal. Effects of voltage and doping were examined, resulting in a clear trend of degradation and decontamination performance proportional to the doping concentration and applied voltage giving the best result at 2.5 V for 10% Ti4O7 doping. The LIG-Ti4O7 surfaces also showed biofilm inhibition against mixed bacterial culture. The flow-through filtration using a LIG-Ti4O7 conductive filter showed complete bacterial killing with 6 log removal in the permeate at 2.5 V, an enhancement of ∼2.5 log compared to undoped LIG filters at a flow rate of ∼500 L m-2 h-1. The facile fabrication of Ti4O7-doped LIG with enhanced electrochemical properties can be effectively used for energy and environmental applications.

Freestanding Laser-Induced Graphene Ultrasensitive Resonative Viral Sensors.

Early and reliable detection of an infectious viral disease is critical to accurately monitor outbreaks and to provide individuals and health care professionals the opportunity to treat patients at the early stages of a disease. The accuracy of such information is essential to define appropriate actions to protect the population and to reduce the likelihood of a possible pandemic. Here, we show the fabrication of freestanding laser-induced graphene (FLIG) flakes that are highly sensitive sensors for high-fidelity viral detection. As a case study, we show the detection of SARS-CoV-2 spike proteins. FLIG flakes are nonembedded porous graphene foams ca. 30 µm thick that are generated using laser irradiation of polyimide and can be fabricated in seconds at a low cost. Larger pieces of FLIG were cut forming a cantilever, used as suspended resonators, and characterized for their electromechanics behavior. Thermomechanical analysis showed FLIG stiffness comparable to other porous materials such as boron nitride foam, and electrostatic excitation showed amplification of the vibrations at frequencies in the range of several kilo-hertz. We developed a protocol for aqueous biological sensing by characterizing the wetting dynamic response of the sensor in buffer solution and in water, and devices functionalized with COVID-19 antibodies specifically detected SARS-CoV-2 spike protein binding, while not detecting other viruses such as MS2. The FLIG sensors showed a clear mass-dependent frequency response shift of ∼1 Hz/pg, and low nanomolar concentrations could be detected. Ultimately, the sensors demonstrated an outstanding limit of detection of 2.63 pg, which is equivalent to as few as ∼5000 SARS-CoV-2 viruses. Thus, the FLIG platform technology can be utilized to develop portable and highly accurate sensors, including biological applications where the fast and reliable protein or infectious particle detection is critical.

Lipid clustering by three homologous arginine-rich antimicrobial peptides is insensitive to amino acid arrangement and induced secondary structure.

Three Arg-rich nonapeptides, containing the same amino acid composition but different sequences, PFWRIRIRR-amide (PR-9), RRPFWIIRR-amide (RR-9) and PRFRWRIRI-amide (PI-9), are able to induce segregation of anionic lipids from zwitterionic lipids, as shown by changes in the phase transition properties of lipid mixtures detected by differential scanning calorimetry and freeze fracture electron microscopy. The relative Minimal Inhibitory Concentration (MIC) of these three peptides against several strains of Gram positive bacteria correlated well with the extent to which the lipid composition of the bacterial membrane facilitated peptide-induced clustering of anionic lipids. The lower activity of these three peptides against Gram negative bacteria could be explained by the retention of these peptides in the LPS layer. The membrane morphologies produced by PR-9 as well as by a cathelicidin fragment, KR-12 that had previously been shown to induce anionic lipid clustering, was directly visualized using freeze fracture electron microscopy. This work shows the insensitivity of phase segregation to the specific arrangement of the cationic charges in the peptide sequence as well as to their tendency to form different secondary structures. It also establishes the role of anionic lipid clustering in the presence of zwitterionic lipids in determining antimicrobial selectivity.

A novel in vivo cell-wall labeling approach sheds new light on peptidoglycan synthesis in Escherichia coli.

Peptidoglycan synthesis and turnover in relation to cell growth and division has been studied by using a new labeling method. This method involves the incorporation of fluorescently labeled peptidoglycan precursors into the cell wall by means of the cell-wall recycling pathway. We show that Escherichia coli is able to import exogenous added murein tripeptide labeled with N-7-nitro-2,1,3-benzoxadiazol-4-yl (AeK-NBD) into the cytoplasm where it enters the peptidoglycan biosynthesis route, resulting in fluorescent labels specifically located in the cell wall. When wild-type cells were grown in the presence of the fluorescent peptide, peptidoglycan was uniformly labeled in cells undergoing elongation. Cells in the process of division displayed a lack of labeled peptidoglycan at mid-cell. Analysis of labeling patterns in cell division mutants showed that the occurrence of unlabeled peptidoglycan is dependent on the presence of FtsZ, but independent of FtsQ and FtsI. Accumulation of fluorescence at the division sites of a triple amidase mutant (ΔamiABC) revealed that AeK-NBD is incorporated into septal peptidoglycan. AmiC was shown to be involved in the rapid removal of labeled peptidoglycan side chains at division sites in wild-type cells. Because septal localization of AmiC is dependent on FtsQ and FtsI, this points to the presence of another peptidoglycan hydrolase activity directly dependent on FtsZ.

Electrochemical Removal of Organic and Inorganic Pollutants Using Robust Laser-Induced Graphene Membranes.

The removal of emerging environmental pollutants in water and wastewater is essential for high drinking water quality or for discharge to the environment. Electrochemical treatment is a promising technology shown to degrade undesirable organic compounds or metals via oxidation and reduction, and carbon-based electrodes have been reported. Here, we fabricated a robust, porous laser-induced graphene (LIG) electrode on a commercial water treatment membrane using the multilasing technique and demonstrated the electrochemical removal of iohexol, an iodine contrast compound, and chromium(VI), a highly toxic heavy metal ion. Multiple lasing resulted in a more ordered graphitic lattice, a more physically robust carbon layer, and a 3-4-fold higher electrical conductivity. These properties ultimately led to a more efficient electrochemical process, and the optimized LIG electrodes showed a higher hydrogen peroxide (H2O2) generation. At 3 V, 90% of Cr(VI) was removed after 6 h and reached >95% removal after 8 h at pH 2. Cr(VI) was mainly reduced to Cr(III), with small amounts of Cr(I) and Cr(0), which were partially deposited on the electrode membrane surface, confirmed with X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy analysis. Under the same conditions, 50% of iohexol was degraded after 6 h and the transformation products (TPs) were identified using ultra-performance liquid chromatography coupled with mass spectroscopy. A total of seven main intermediates were identified including deiodinated TPs (m/z = 695, 570, and 443), probably occurring via three transformation pathways including oxidative deiodination, amide hydrolysis, and deacetylation. The electrical energy costs calculated for the removal of 2 mg L-1 Cr(VI) was ∼$0.08/m3 in this system. Taken together, the porous LIG electrodes might be utilized for electrochemical removal of emerging contaminants in multiple applications because they can be rapidly formed on flexible polymer substrates at low cost.