Porphyrin-based Porous Organic Polymer Research Articles

Hg2+-enhanced oxidase-like activity of platinum nanoparticles immobilized on porphyrin-based porous organic polymer for the colorimetric detection and removal of Hg2.

Porphyrin-based porous organic polymer (POP) with uniformly immobilized platinum nanoparticles (Pt NPs) were designed and synthesized, and it was demonstrated that such nanocomposites (Pt/POP) have oxidase-like activity. Surprisingly, Hg2+ significantly enhanced the oxidase-like activity of Pt/POP. The enhancement was attributed to the capture of Hg2+ by the thioether group in Pt/POP and the subsequent redox reaction of Hg2+ with Pt NPs, accelerating the electron transfer. In the presence of Hg2+, Pt/POP catalyzed the colorless 3,3',5,5'-tetramethylbenzidine (TMB) to turn blue rapidly and changed its absorbance at 652nm. Based on this, a fast-response colorimetric sensor was constructed for the sensitive detection of Hg2+ with a linear range of 0.2-50μM and a detection limit of 36.5nM. Importantly, Pt/POP can be used as an adsorbent for the efficient removal of Hg2+ with a removal efficiency as high as 99.4%. This work provides a valuable strategy for colorimetric detection and efficient removal of Hg2+.

Porous Fe-Porphyrin as an Efficient Adsorbent for the Removal of Ciprofloxacin from Water.

Antibiotics are widely used in medicine, but they are not fully metabolized in the body and can end up in wastewater. Conventional wastewater treatment methods fail to completely remove antibiotic residues, which can then enter rivers and streams. Adsorption is a promising technique for removing antibiotics from wastewater, even at low concentrations. The successful one-pot synthesis of an adsorbent, iron-containing porphyrin-based porous organic polymer (Fe-POP), was achieved through the reaction of pyrrole groups and terephthalaldehyde in the presence of FeCl3. Characterized by a substantial BET surface area of 597 m2 g-1, Fe-POP was systematically investigated for its adsorption potential in the removal of the antibiotic Ciprofloxacin (CIP) from aqueous solutions. By systematic variation of key parameters, including pH, adsorbent loading, and CIP concentration, the adsorption conditions were optimized. Under the optimal conditions at pH = 3, CIP concentration of 5 ppm, and 25 mg of Fe-POP, the maximum adsorption capacity reached an impressive 263 mg g-1. The robust adsorption behavior was elucidated through the fitting of experimental data to the Langmuir adsorption isotherm (R2 = 0.962) and the pseudo-second-order kinetic model (R2 = 0.999) with lower error values. These models suggested that the adsorption process predominantly involved chemical interactions between CIP molecules and the Fe-POP surface. Fe-POP exhibited a robust structure with a high adsorption capacity, showcasing its efficacy in removing CIP contaminants from water. Therefore, Fe-POP can be considered a valuable adsorbent for water treatment applications, specifically for antibiotic removal.

A stable porphyrin-based porous organic polymer as highly efficient heterogeneous photocatalyst for the oxidative homocoupling of amines

With permanent photosensitivity and intrinsic porosity, porphyrin-based porous organic polymers (POPs) are potential candidates for photocatalytic reactions. Herein, H2Pp-POP was prepared via the free radical self-polymerization of [5,10,15,20-tetrakis(4-((4-vinylbenzyl)oxy)phenyl)porphyrin] (H2Pp) containing terminal styrene groups. The as-prepared H2Pp-POP possess superior photosensitivity, abundant pore structure, and robust stability, which endow it remarkable photocatalytic activity and recyclability. As a result, H2Pp-POP exhibits an excellent photocatalytic performance in the oxidative homocoupling of amines into imines, with high conversion rate and selectivity. This study provides a valuable way to synthesize efficient heterogeneous photocatalysts for the conversion of amine.

Porphyrin-based porous organic polymers synthesized using the Alder-Longo method: the most traditional synthetic strategy with exceptional capacity.

Porphyrin is a typical tetrapyrrole chromophore-based pigment with a special electronic structure and functionalities, which is frequently introduced into various porous organic polymers (POPs). Porphyrin-based POPs are widely used in various fields ranging from environmental and energy to biomedicine-related fields. Currently, most porphyrin-based POPs are prepared via the copolymerization of specific-group-functionalized porphyrins with other building blocks, in which the tedious and inefficient synthesis procedure for the porphyrin greatly hinders the development of such materials. This review aimed to summarize information on porphyrin-based POPs synthesized using the Alder-Longo method, thereby skipping the complex synthesis of porphyrin-bearing monomers, in which the porphyrin macrocycles are formed directly via the cyclic tetramerization of pyrrole with monomers containing multiple aldehyde groups during the polymerization process. The representative applications of porphyrin-based POPs derived using the Alder-Longo method are finally introduced, which pinpoints a clear relationship between the structure and function from the aspect of the building blocks used and porous structures. This review is therefore valuable for the rational design of efficient porphyrin-based porous organic polymer systems that may be utilized in various fields from energy-related conversion/storage technologies to biomedical science.

Three-dimensional sulfonic-functionalized porphyrin-based porous organic polymer for high-performance methylene blue and ciprofloxacin capture

The pollution of toxic organic dyes and unmetabolized antibiotics to environments was becoming increasingly serious, therefore, it was urgent to remove them. In this paper, a three-dimensional hypercrosslinked porphyrin-based porous organic polymer (TP-PPOPs) with 5,10,15,20-tetraphenylporphyrin and triptycene as monomers was designed and synthesized for the first time. By further reacting TP-PPOPs with chlorosulfonic acid, a new three-dimensional sulfonic acid functional material (TP-PPOPs-SO3H) with significantly improved electronegativity and hydrophilicity was obtained. Both reactions were mild and no expensive metal catalysts were required. Benefiting from the hypercrosslinked structure, stable three-dimensional rigid framework, abundant adsorption active sites and high specific surface area, TP-PPOPs-SO3H exhibited extremely fast adsorption rate, outstanding adsorption selectivity, extraordinary reusability and ultra-high adsorption capacity for MB and CIP, with the maximum adsorption capacities being 1283.33 mg·g−1 for MB and 485.39 mg·g−1 for CIP, respectively. The study of adsorption mechanism revealed that the ultra-high adsorption capacity of TP-PPOPs-SO3H on MB and CIP was mainly attributed to their strong electrostatic interaction and the extended π-conjugated frameworks and large specific surface area of TP-PPOPs-SO3H.

Hollow porphyrin-based porous organic polymer with dual enzyme-like activities for ultra-fast colorimetric detection of Cr (VI) in wastewater.

A hollow porphyrin-based porous organic polymer (H-Fe-POP) was prepared for rapid and sensitive colorimetric determination of Cr(VI), which exhibited excellent dual enzyme-like activities, including oxidase-like and peroxidase-like activities. Due to the specific binding of 8-hydroxyquinoline (8-HQ) to Cr(VI), 3,3',5,5'-tetramethylbenzidine (TMB) was liberated, and TMB was oxidized to blue ox-TMB catalyzed by H-Fe-POP. Based on the excellent oxidase-like activity of H-Fe-POP, an ultra-fast colorimetric platform for the detection of Cr(VI) was constructed, allowing the quantification of Cr(VI) in the range 2-130 μM within 30 s with a detection limit of 0.23 μM. Importantly, the sensor can accurately determine Cr(VI) in industrial wastewater, indicating its high potential for environmental monitoring.

A copper decorated porphyrin-based porous organic polymer: Evaluation in the oxidation of lignin model compounds

A novel porous organic polymer containing porphyrin units was synthesized and decorated with copper to produce the metallated POP, Cu-TriPOP. The native POP, Nat-TriPOP and metal-decorated Cu-TriPOP exhibited BET surface areas of 595 m2/g and 373 m2/g, respectively. Excellent thermal stability up to 300 °C was observed by thermogravimetric analysis. Transmission electron microscopy (TEM) showed a sea urchin/bush-like morphology. The metal-decorated POP, Cu-TriPOP, was evaluated in the oxidation of veratryl alcohol and other related substrates. Excellent catalytic performance was achieved with conversions of around 80%. The addition of ascorbic acid, a well-known radical scavenger, significantly reduced the activity, suggesting that a radical mechanism is most likely operative. In addition, excellent catalyst recovery and recyclability were achieved for up to five cycles with minimal decrease in activity.

Porphyrin-based porous organic polymer coated ZIF-8 nanoparticles as tumor targeted photosensitizer for combination cancer photodynamic/photothermal therapy

The issue of low tumor-targeting and easy aggregation of small-molecule photosensitizers (PSs), as well as the heterogeneity and complexity of tumor tissue, greatly limit the therapeutic efficiency of phototherapy. Herein, a porphyrin-based organic polymer (POP) coated zeolitic imidazolate framework-8 (ZIF-8) hybrid nanoparticles (POP@ZIF-8) was developed, for delivering photosensitizer (porphyrin-based POP) specifically into tumor sites. The low-cost, biocompatible, tumor-specific POP@ZIF-8 with core-shell structure was prepared via a simple but efficient covalent surface-coating strategy, in which the pH-responsive ZIF-8 functioned as templates, finely controlling the nanometer size of the hybrid and ensuring targeted delivery of PSs to tumor tissue. Moreover, a direct covalently coated polymer-based PSs on ZIF-8 can better preserve optical properties compared to conventional physical adsorption methods. Under laser irradiation, the resulting hybridization not only efficiently converts light into local heat, causing severe photothermal damage to tumor tissue, but also synergistically promotes the production of strongly toxic 1O2, which exerts a photodynamic treatment on tumor sites. Therefore, this special POP@ZIF-8 hybrid presented a cooperatively enhanced synergistic photodynamic/photothermal anticancer efficacy, as demonstrated both the in vitro and in vivo assay, systematically. This study presents a practicable and reliable strategy to develop stable and high-efficiency cancer phototherapy agents which could simultaneously manipulate the structural characteristics and performance of targeted materials for promising noninvasive multi-mode anti-cancer.

Copper(II)-Incorporated Porphyrin-Based Porous Organic Polymer for a Nonenzymatic Electrochemical Glucose Sensor.

To date, the fabrication of multifunctional nanoplatforms based on a porous organic polymer for electrochemical sensing of biorelevant molecules has received considerable attention in the search for a more active, robust, and sensitive electrocatalyst. Here, in this report, we have developed a new porous organic polymer based on porphyrin (TEG-POR) from a polycondensation reaction between a triethylene glycol-linked dialdehyde and pyrrole. The Cu(II) complex of the polymer Cu-TEG-POR shows high sensitivity and a low detection limit for glucose electro-oxidation in an alkaline medium. The characterization of the as-synthesized polymer was done by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and 13C CP-MAS solid-state NMR. The N2 adsorption/desorption isotherm was carried out at 77 K to analyze the porous property. TEG-POR and Cu-TEG-POR both show excellent thermal stability. The Cu-TEG-POR-modified GC electrode shows a low detection limit (LOD) value of 0.9 μM and a wide linear range (0.001-1.3 mM) with a sensitivity of 415.8 μA mM-1 cm-2 toward electrochemical glucose sensing. The interference of the modified electrode from ascorbic acid, dopamine, NaCl, uric acid, fructose, sucrose, and cysteine was insignificant. Cu-TEG-POR exhibits acceptable recovery for blood glucose detection (97.25-104%), suggesting its scope in the future for selective and sensitive nonenzymatic glucose detection in human blood.

Degradable Multifunctional Porphyrin-Based Porous Organic Polymer Nanosonosensitizer for Tumor-Specific Sonodynamic, Chemo- and Immunotherapy.

Sonodynamic therapy (SDT) benefiting from its intrinsic merits, such as noninvasiveness and deep tissue penetrability, is receiving increasing considerable attention in reactive oxygen species (ROS)-based tumor treatment. However, current sonosensitizers usually suffer from low tumor lesion accumulation, insufficient ROS generation efficiency under ultrasound, and non-biodegradability, which seriously impede the therapeutic outcomes. Additionally, it is difficult that SDT alone can completely eradicate tumors because of the complex and immunosuppressive tumor microenvironment (TME). Herein, we simultaneously employ sonosensitive porphyrin building blocks and glutathione (GSH)-responsive disulfide bonds to construct a novel degradable multifunctional porphyrin-based hollow porous organic polymer (POP) nanosonosensitizer (H-Pys-HA@M/R), which combine SDT, "on-demand" chemotherapy, and immunotherapy. Taking the unique advantages of POPs with designable structures and high specific surface area, this H-Pys-HA@M/R nanosonosensitizer can achieve tumor target accumulation, GSH-triggered drug release, and low-frequency ultrasound-activating ROS generation with encouraging results. Furthermore, this multifunctional nanosonosensitizer can effectively evoke immunogenic cell death (ICD) response through the combination of SDT and chemotherapy for both primary and distal tumor growth suppression. Meanwhile, H-Pys-HA@M/R exhibits favorable biodegradation and biosafety. Therefore, this study provides a new strategy for reasonably designing and constructing POP-related sonosensitizers combining SDT/chemotherapy/immunotherapy triple treatment modalities to eradicate malignant tumors.

Iron porphyrin-based porous organic polymer with high peroxidase-like activity as colorimetric sensor for glutathione and ascorbic acid assay.

A new iron porphyrin-based organic polymer (Fe-POP) was synthesized through the William ether reaction. The as-prepared Fe-POP presented high chemical stability, wide pore distribution, high iron content, and strong affinity with 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2), which contributed to its excellent peroxidase-mimicking performance. In the presence of H2O2, Fe-POP could catalyze the transparent TMB into blue ox-TMB, which could be easily distinguished by the naked eyes. Moreover, glutathione (GSH) and ascorbic acid (AA) could convert blue ox-TMB into colorless TMB due to the inhibitory effect of GSH/AA to the catalytic oxidation of TMB. Based on this phenomenon, a rapid and sensitive colorimetric method for the assay of H2O2, GSH, and AA was developed using Fe-POP as sensor. The detection limits of H2O2, GSH, and AA were 1.37, 0.44, and 0.33μM, respectively. Finally, the colorimetric method based on Fe-POP was used to evaluate the GSH and AA content in real samples, which provided the guidance for GSH and AA supplements in our daily diet, suggesting the significant potential of Fe-POP in practical applications.

A new synthetic strategy of Aluminium(III)-porphyrin-based conjugated microporous polymers with efficient CO2 catalytic conversion at ambient conditions

The conversion of CO2 cycloaddition to value-added cyclic carbonates is of considerable interest owing to the renewable greenhouse gas and 100 % atomic economy. However, it is still a big challenge to develop low-cost and high-efficient catalysts. Here, we report a facile design way, in a single step, for the creation of robust catalytic nanoreactors for heterogeneous catalyst in the cycloaddition of CO2 to cyclic carbonates. The Al(III)-porphyrin-based porous organic polymer catalysts exhibited remarkably high efficiency for propylene carbonate with turnover frequencies of up to 443.6 h−1 at room temperature and atmospheric pressure without solvent, which notably surpasses most previously reported heterogeneous catalysts and relevant homogeneous catalysts. Even using dilute CO2 (15 % CO2 in N2), a TOF up to 27.0 h−1 could be afforded under ambient conditions (25 °C, 1 bar) by Al-Por-POP-2, which showed high stability for recyclability up to 10 times without a significant decrease. These studies provided a simple and efficient synthetic strategy infavorof mass production and future industrial application for the cycloaddition of CO2 with low cost and high efficiency.

Facile fabrication of iron porphyrin-based porous organic polymer with excellent oxidase-like activity for colorimetric detection of sulfide

The high concentration of sulfide in environment does great harm to human beings’ health due to its toxicity, corrosivity, and disagreeable odor. Therefore, it's highly urgent to develop a simple, selective, and sensitive method for sulfide ion detection. In this work, we synthesized an iron porphyrin-based porous organic polymer (Fe-PPOP) through a facile Friedel-Crafts reaction. The structure of Fe-PPOP was confirmed through a series of methods, such as FT-IR, SEM, EDS, TEM, XPS and nitrogen physisorption. Fe-PPOP exhibited high oxidase-like activity, which could catalyze the oxidization of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue product (ox-TMB) in the presence of oxygen. With the addition of sulfide ion to the above system, the color of solution gradually changed from blue to colorless. Therefore, the Fe-PPOP/TMB system could be used for sulfide detection through a facile colorimetric method. The interference experiments using other similar ions verified the high selectivity of Fe-PPOP for sulfide detection. The limit of detection (LOD) of sulfide was calculated to be 1.08 μM. This work provided a promising method for sulfide measurement in environmental pollutants with high reliability and accuracy.

In-situ generation of highly active and four-in-one CoFe2O4/H2PPOP nanozyme: Mechanism and its application for fast colorimetric detection of Cr (VI)

Nanozymes have been widely utilized in colorimetric sensors and developing nanomaterials with multienzyme functions have more application prospects due to their cascaded catalytic efficiency. Here, a unique organic-inorganic nanocomposite CoFe2O4/H2PPOP was synthesized by depositing CoFe2O4 nanocubes on a fully conjugated porphyrin-based porous organic polymer (H2PPOP) in situ. CoFe2O4/H2PPOP revealed outstanding tetra-enzyme-like activities, namely oxidase-like, peroxidase-like, catalase-like and superoxide dismutase-like activities. Compared with pure CoFe2O4 nanocubes, the catalytic activities of CoFe2O4/H2PPOP were significantly boosted because of the large surface area and extended conjugated structure of H2PPOP, abundant active substances (CoFe2O4) on the surface and the effective electronic transfer between CoFe2O4 and H2PPOP. Based on the oxidase-like activity of CoFe2O4/H2PPOP, a colorimetric platform was constructed for Cr (VI) with a wide linear range (0.6–100 μM) and a low detection limit (26 nΜ). Further utilizing the double oxidase-like and peroxidase-like activities, a more sensitive colorimetric platform with a faster detection speed for Cr (VI) was realized with the LOD as low as 2 nΜ. This work opens up a new way to prepare multi-enzyme active nanozyme and excavates its potential for detecting environmental pollutants.

Magnetic Solid Phase Extraction Based on Nanostructured Magnetic Porous Porphyrin Organic Polymer for Simultaneous Extraction and Preconcentration of Neonicotinoid Insecticides From Surface Water.

In this study, a magnetic porphyrin-based porous organic polymer (MP-POP) nanocomposite was successfully synthesized according previous studies and applied as an adsorbent for simultaneous extraction and preconcentration of four neonicotinoid insecticides from surface river water. The MP-POP was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS), N2-adsorption/desorption analysis, Fourier Transform infrared spectroscopy (FTIR). The neonicotinoid insecticides were quantified using high performance chromatography coupled with diode array detector (HPLC-DAD). The MP-POP shown to have a high surface area, highly porous structure and strong affinity toward the investigated analytes. The adsorption capacities were 99.0, 85.5, 90.0, and 79.4 mg g−1 for acetamiprid, clothiandin, thiacloprid and imidacloprid, respectively. The influential parameters affecting the magmatic μ-solid phase extraction (M-μ-SPE) procedure were investigated using fractional factorial design and surface response methodology (RSM). Under optimum conditions, the method exhibited relatively low limit of detection in the range of 1.3–3.2 ng L−1, limit of quantification in the range of 4.3–11 ng L−1 and wide linearity (up to 600 μg L−1). The intraday and interday precision, expressed as the relative standard deviation (RSD) were <5%. The percentage recoveries for the four target analytes ranged from 91 to 99.3% for the spiked river water samples. The method was applied for determination of neonicotinoids in river water samples and concentrations ranged from 0 to 190 ng L−1.

Porphyrin-Based Porous Organic Polymer as Peroxidase Mimics for Sulfide-Ion Colorimetric Sensing

The effective synthesis of functional nanoplatforms for simple, selective, and sensitive hydrogen sulfide detection has received significant attention because of the toxicity of hydrogen sulfide. H...

Bacterial Detection and Elimination Using a Dual-Functional Porphyrin-Based Porous Organic Polymer with Peroxidase-Like and High Near-Infrared-Light-Enhanced Antibacterial Activity.

The efficient fabrication of multifunctional nanoplatforms for bacterial detection and elimination is of great importance in nanobiotechnology. A new porphyrin-based porous organic polymer, FePPOPBFPB, was synthesized via the reaction between pyrrole and 4-{2,2-bis[(4-formylphenoxy)methyl]-3-(4-formylphenoxy) propoxy} benzaldehyde (BFPB). The C-centric tetrahedral structure of BFPB promoted the formation of FePPOPBFPB with a 3D interconnected porous structure, high specific surface area, and plentiful surface catalytic active sites. The adjustable structural alkyl chain also enhanced the absorption capability of FePPOPBFPB in the long-wavelength visible and near-infrared regions (NIR). FePPOPBFPB exhibited excellent peroxidase-like activity toward a representative peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB) with H2O2. Utilizing these features, a rapid and visual detection of Staphylococcus aureus (S. aureus) based on FePPOPBFPB was established and exhibited high sensitivity and stability. Combining the catalysis with near-infrared-light (NIR) absorption, FePPOPBFPB can effectively catalyze the decomposition of biologically relevant concentrations of H2O2 to produce vast amounts of •OH radicals via the photo-Fenton reaction, which avoids the utilization of high toxic concentrations of H2O2. On the basis of these satisfactory features, FePPOPBFPB had a conspicuous bactericidal performance against S. aureus under NIR irradiation. To our knowledge, this is the first example of a porphyrin-based porous organic polymer antibacterial agent. The main reactive oxygen species (ROS) produced in this system and the possible antibacterial mechanism of FePPOPBFPB was also proposed through a series of experiments.

Visible-light-driven photo-Fenton degradation of organic pollutants by a novel porphyrin-based porous organic polymer at neutral pH.

Developing novel heterogeneous photo-Fenton catalysts with high efficiency and stability, driven by visible-light rather ultraviolet light at neutral pH has been a major challenge for degradation of organic pollutants. In this work, we successfully synthesized a metalloporphyrin-based porous organic polymer (FePPOP-1) by the Sonogashira cross-coupling reaction. UV-vis absorption spectra showed FePPOP-1 exhibits a significant coverage of the natural solar irradiance spectrum. As a result, the prepared FePPOP-1 has a significantly enhanced photocatalytic activity for the visible-light-driven degradation of methylene blue. By using only 4 mg of FePPOP-1 as a catalyst, it was found that 50 mL of organic wastewater containing 70 ppm MB could be totally degraded in 80 min even at neutral pH. The effects of the initial MB, H2O2 concentrations, pH value and common ions on MB degradation were studied in detail. Both the catalytic mechanism of FePPOP-1 and the degradation route of MB were also proposed.

Porphyrin-based porous organic polymer, Py-POP, as a multifunctional platform for efficient selective adsorption and photocatalytic degradation of cationic dyes

Abstract In this study, the porphyrin based porous organic polymer, Py-POP, is estimated to be an efficient multifunctional platform integrating adsorption and photocatalysis. For model dyes of methylene blue (MB) and rhodamine B (RhB) which are with same cationic charge and little difference in size, Py-POP exhibits excellent selective adsorption capacity for MB. Furthermore, Py-POP exhibits good photocatalytic ability in the degradation of both RhB and MB/RhB mixture under visible light source irradiation. The adsorption kinetics can be fitted well with the pseudo-second-order kinetic model and the photocatalytic mechanism study reveals that singlet oxygen and hydroxyl radical simultaneously act as reactive species in photodegradation. As a stable, recyclable, multifunctional platform integrating selective adsorption and photocatalysis, Py-POP provides the material basis for novel industrial route design for dye wastewater treatment technique. Our findings highlight an appealing opportunity for porous organic polymers with their potential application as multifunctional platform for efficient dye separation and treatment.

Sensitive determination of psoralen and isopsoralen in Fructus Psoraleae by online solid phase microextraction with a porphyrin-based porous organic polymer modified capillary

A novel porphyrin based porous organic polymer modified capillary (PPOP-capillary) was prepared for the extraction of psoralen and isopsoralen in Fructus Psoraleae.