Linker-Preserved Iron Metal-Organic Framework-Based Lateral Flow Assay for Sensitive Transglutaminase 2 Detection in Urine Through Machine Learning-Assisted Colorimetric Analysis.

A groundbreaking demonstration of the utilization of the metal-organic framework MIL-101(Fe) as an exceptionally perceptive visual label in colorimetric lateral flow assays (LFA) is described. This pioneering approach enables the precise identification of transglutaminase 2 (TGM2), a recognized biomarker for chronic kidney disease (CKD), in urine specimens, which offers a remarkably sensitive naked-eye detection mechanism. The surface of MIL-101(Fe) was modified with oxalyl chloride, adipoyl chloride, and poly(acrylic) acid (PAA); these not only improved the labeling material stability in a complex matrix but also achieved a systematic control in the detection limit of the TGM2 concentration using our LFA platform. The advanced LFA with the MIL-101(Fe)-PAA label can detect TGM2 concentrations down to 0.012, 0.009, and 0.010 nM in Tris-HCl buffer, urine, and desalted urine, respectively, which are approximately 55-fold lower than those for a conventional AuNP-based LFAs. Aside from rapid TGM2 detection (i.e., within 20 min), the performance of the MIL-101(Fe)-PAA-based LFA on reproducibility [coefficients of variation (CV) < 2.9%] and recovery (95.9-103.2%) along with storage stability within 25 days of observation (CV < 6.0%) shows an acceptable parameter range for quantitative analysis. A sophisticated sensing method grounded in machine learning principles was also developed, specifically aimed at precisely deducing the TGM2 concentration by analyzing immunoreaction sites. More importantly, our developed LFA offers potential for clinical measurement of TGM2 concentration in normal human urine and CKD patients' samples.

Insights into the Structure-Property-Activity Relationship of Zeolitic Imidazolate Frameworks for Acid-Base Catalysis.

Zeolitic imidazolate frameworks (ZIFs) have been extensively examined for their potential in acid-base catalysis. Many studies have demonstrated that ZIFs possess unique structural and physicochemical properties that allow them to demonstrate high activity and yield products with high selectivity. Herein, we highlight the nature of ZIFs in terms of their chemical formulation and the textural, acid-base, and morphological properties that strongly affect their catalytic performance. Our primary focus is the application of spectroscopic methods as instruments for analyzing the nature of active sites because these methods can allow an understanding of unusual catalytic behavior from the perspective of the structure-property-activity relationship. We examine several reactions, such as condensation reactions (the Knoevenagel condensation and Friedländer reactions), the cycloaddition of CO2 to epoxides, the synthesis of propylene glycol methyl ether from propylene oxide and methanol, and the cascade redox condensation of 2-nitroanilines with benzylamines. These examples illustrate the broad range of potentially promising applications of Zn-ZIFs as heterogeneous catalysts.

Adsorptive removal of aromatic diamines from water using metal-organic frameworks functionalized with a nitro group.

Adsorptive removal of aromatic diamines such as methylenedianiline (MDA) and p-phenylenediamine (PPD) was firstly investigated with nitro-functionalized metal-organic frameworks (MOFs, MIL-101(Cr)-NO2). The MIL-101(Cr)-NO2 showed much better performances in the removal of MDA and PPD, in both adsorption capacity and kinetics, than any other adsorbents. For example, MIL-101(Cr)-NO2 had a much higher maximum adsorption capacity for MDA (1111 mg·g-1) than activated carbon (208 mg·g-1) or a reported adsorbent (391 mg·g-1). Based on experimental results, hydrogen bonding (especially, via the formation of a 6-membered ring (6-MR) between -NO2 of the adsorbent and -NH2 of the adsorbates) could be suggested as the main mechanism to interpret the noticeable adsorption of the diamines. Importantly, this is the first example to confirm that MOFs with nitro group can be a competitive adsorbent to remove organics composed of amino group, especially via making 6-MR through hydrogen bonding. Higher adsorption of MDA than that of PPD over MIL-101(Cr)-NO2 might be explained with π-π interaction between aromatic rings (π-lean aromatics of MOF and π-rich aromatics of the adsorbates). Moreover, MIL-101(Cr)-NO2 could be recycled after simple washing, suggesting the potential use of the MOF in adsorptive purification of contaminated water with organics with amino groups.

Pore creation nanoarchitectonics from non-porous metal-organic framework to porous carbon for adsorptive elimination of sulfanilamide and chloroxylenol from aqueous solution.

Three isomeric metal-organic frameworks (MOFs) such as MAF-5, - 6, and - 32 (with the same composition of [Zn(2-ethylimidazole)2]) were carbonized and, for the first time, activated further with KOH to prepare highly porous MOF-derived carbons (MDCs). Importantly, MDC-32 derived from non-porous MAF-32 had the highest porosity among the three MDCs although it has the lowest porosity when no KOH activation was done. Adsorption of sulfanilamide and chloroxylenol from water was investigated with the MDCs. Among the MDCs, MDC-32 showed the best adsorptive performance for sulfanilamide and chloroxylenol. Moreover, MDC-32, had the highest adsorption capacity (256 mg/g) for removing sulfanilamide from water, compared with any adsorbent reported so far. Based on the observed adsorption and properties of the adsorbate and adsorbent, π-π and hydrogen bonding interactions, with a slight contribution of repulsive electrostatic interaction, could be suggested as the mechanism for the sulfanilamide adsorption over the MDC-32. Moreover, the MDC-32 could be recycled easily for up to four cycles. It could be suggested that non-porous MOFs can be a good precursor for highly porous MDCs, if activated well using KOH, for example. Finally, MAF-32-derived carbon, MDC-32, might be suggested as a plausible adsorbent to eliminate organics such as sulfanilamide from water.

Functionalized metal-organic framework-derived carbon: Effective adsorbent to eliminate methylene blue, a small cationic dye from water.

Elimination of organic dyes from wastewater is very important for our safe environment and sound health. In this work, adsorptive removal of cationic dyes, especially small ones, was investigated with carbonaceous materials to develop a competitive adsorption technology. To improve the performance of metal-organic framework (MOF)-derived carbons (MDCs) in dye adsorption, an MDC, derived from a MOF (MAF-6), was oxidatively functionalized with ammonium persulfate solutions (APSs). Although the porosity of pristine MDC decreased with functionalization via oxidation, functionalized MDCs (FMDCs), especially FMDC(1.0) that was obtained via treating MDC with APS (1.0 M), showed remarkable performances in the adsorption of small cationic dyes like methylene blue (MB) and azure B. For example, FMDC(1.0) had the maximum adsorption capacity (Qo) of 625.0 mg/g (for MB) which is larger than any reported value with carbonaceous materials. Moreover, the obtained Qo was around 4 and 2 times that of activated carbon with Qo of 160 mg/g and MDC with Qo of 298 mg/g, respectively. On the contrary, oxidative treatment of MDC was negative in adsorption of an anionic dye such as methyl orange. Moreover, the functionalized MDC was not very effective in the adsorption of cationic dyes with large sizes (like brilliant green, crystal violet, Janus green B, and rhodamine B) because of the limited pore size of the studied adsorbent FMDC(1.0). The remarkable adsorption of MB over FMDC(1.0) could be explained by electrostatic and π-π interactions. Finally, the facile recyclability of the FMDC(1.0) in MB adsorption was confirmed via successive adsorptions, FT-IR, and nitrogen adsorption; therefore, FMDC(1.0) can be suggested as a potential adsorbent to remove cationic dyes, especially with small molecular sizes.

Recent research trends in voltammetric sensing platforms for hormones and their applications to human serum analyses.

Hormones are essential chemical messengers that modulate body homeostasis and regulate appetite, mood, reproduction, and metabolism in the human body. Its dysregulation in the body can cause diabetes, Alzheimer's disease, and autism. The detection of hormone levels in biological fluids, including serum samples, could facilitate the precaution, diagnosis, and cure of diseases. Voltammetric sensing devices exhibiting significant sensitivity, selectivity, as well as facile, cost-effective fabrication, are one of the promising methods for detecting hormone levels. Thus, this review briefly highlights recent advances toward developing voltammetric sensors for a wide spectrum of amino acid-derived, peptide, and lipid-derived hormones alongside their applications to the analyses of human serum samples. Furthermore, several challenging issues and the prospects of voltammetric hormone-sensing devices in clinical diagnostic applications are discussed.

Adsorptive removal of herbicides with similar structures from water over nitrogen-enriched carbon, derived from melamine@metal-azolate framework-6.

Based on the recent concern on the pollution of water bodies with herbicides, adsorptive removal of typical herbicides with similar chemical structures, e. g. clofibric acid (CLFA), methylchlorophenoxypropionic acid or mecoprop (MCPP) and 2,4-dichlorophenoxyacetic acid (2,4-D) from water was studied using a porous nitrogen-enriched carbon. To prepare the nitrogen-enriched carbon, pyrolysis of a melamine (MLM) incorporated metal-azolate framework-6 (MLM(x)@MAF6; x = 0-50 M % of the ligand 2-ethylimidazole for MAF6), that was prepared for the first time via an in situ method, was carried out. The MLM(x)@MAF6-derived carbons (MDC6M(x)s) were characterized and used in the removal of CLFA, MCPP and 2,4-D from water. We found that the MDC6M(25), obtained from MLM(25)@MAF6 with 25% MLM (as the optimum precursor composition), showed the highest maximum adsorption capacity (Q0) of 1031 mg/g for CLFA, compared with any reported adsorbents, so far. The physicochemical properties of CLFA, as well as adsorbents and adsorptions under wide pH conditions, were employed to propose a plausible adsorption mechanism including hydrogen bonding. Remarkably, the porous carbon with enriched nitrogen, derived from MAF6 loaded MLM via in situ method, was very competitive in herbicides adsorption because of the contribution of well-dispersed nitrogen sties on the adsorbent. Finally, MDC6M(25) was suggested as a potential adsorbent for the removal of herbcides, including CLFA, MCPP and 2,4-D, from water, which is highly attractive to mitigate the environmental issue, especially, water pollution by various herbicides.

Fluorescent paper strip immunoassay with carbon nanodots@silica for determination of human serum amyloid A1.

A fluorescent paper strip immunoassay in conjunction with carbon nanodots@silica (CND@SiO2) as a label was developed for the quantitative measurements of human serum amyloid A1 (hSAA1) in serum at clinically significant concentrations for lung cancer diagnosis. Monodispersed CND@SiO2 was prepared by cohydrolysis between silane-crosslinked carbon nanodots and silica precursors via the Ströber method and further attached covalently to anti-hSAA1 (14F8) monoclonal antibody [anti-hSAA1(14F8)] specific to the hSAA1 target. The hSAA1 concentrations were then determined by quantifying the blue fluorescence intensity upon 365 nm excitation of the captured hSAA1 with anti-hSAA1(14F8)-CND@SiO2 conjugates in the test line on a paper strip where anti-hSAA1 (10G1) monoclonal antibody was physisorbed. The developed fluorescent paper strip with CND@SiO2 can detect hSAA1 at concentrations ranging from 0.1 to 5 nM (R2 = 0.995), with a limit of detection of  0.258 nM in 10 mM phosphate buffer pH 7.4 containing human serum albumin. The performance of  recovery (90.98-109.17%) and repeatability (coefficients of variation < 8.46%) obtained was also acceptable for quantitative determinations. The platform was employed for direct determination of hSAA1 concentrations in undiluted serum samples from lung cancer patients (relative standard deviation (RSD) < 7.46%) and healthy humans (RSD < 3.96%). The results were compared with those obtained using a commercially available enzyme-linked immunosorbent assay alongside liquid chromatography with tandem mass spectrometry measurements.

Removal of Particulate Matters by Using Zeolitic Imidazolate Framework-8s (ZIF-8s) Coated onto Cotton: Effect of the Pore Size of ZIF-8s on Removal.

Removal of particulate matter (PM) like PM2.5 and PM10 from air was carried out with cotton coated with metal-organic frameworks (MOFs) having various pore sizes to understand the effect of the pore size of MOFs (here, ZIF-8s) on the performances in PM elimination. Both removal efficiency and quality factor, based on the unit surface area of ZIF-8s, in the filtration of PMs with ZIF-8/cotton did not rely considerably on the pore size of ZIF-8s. More importantly, small pores (even less than 0.5 nm) of conventional MOFs like ZIF-8 are more than enough in the elimination of large PMs like PM10 with a size of microns probably because small active sites (such as polar functional groups) on PMs can interact with porous materials having polarity. Additionally, electrostatic interactions between PMs and porous materials could be confirmed as a plausible mechanism for PM removal with ZIF-8/cotton.

Ionic Salts@Metal-Organic Frameworks: Remarkable Component to Improve Performance of Fabric Filters to Remove Particulate Matters from Air.

The elimination of particulate matters (PMs) from the air is very important for our sustainability. In this study, highly porous metal-organic frameworks (MOFs) like MIL-101 and UiO-67 were first modified, coated onto cotton, and applied in PM removal via filtration. Ionic salts (ISs) like CaCl2 and LiCl, after loading onto the MOFs, remarkably increased the PM removal efficiency. For example, CaCl2(20)@MIL-101/cotton shows 5.7 times the quality factor (QF, which is the most important parameter in filtration) of that of bare cotton and has the most competitive performances in PM removal (with the highest QF of 0.085 Pa-1) compared to any filter modified with porous materials or commercial filters. The noticeable performances of ISs@MOFs can be explained by the contribution of charge separation (that is effective for electrostatic interactions with PMs) of ISs and the high porosity of MOFs. Moreover, how MOFs with small pores of a few nanometers or less can remove large PMs with sizes in the micron range could be explained. Finally, loading ISs onto highly porous materials can be a promising strategy to improve the performances of filters to remove PMs from the air.

How neutral nitrogen-containing compounds are oxidized in oxidative-denitrogenation of liquid fuel with TiO2@carbon.

Oxidative-denitrogenation (ODN) of indole (IND) and methyl-substituted INDs (methyl-INDs), representative neutral nitrogen-containing compounds (NCCs), was carried out with TiO2@C and H2O2 as heterogeneous catalyst and oxidant, respectively, under ultrasound irradiation. The oxidation of INDs progressed through radical formation, as evidenced by electron spin resonance and radical scavenger experiments. The oxidized position of INDs in the ODN process was checked via characterization of the obtained products. It was observed that the oxidation finally occurred on the carbon rather than on the nitrogen atom of INDs, unlike the oxidation of basic NCCs (e.g., oxidation on the nitrogen atom, as respective N-oxides were formed) and sulfur-containing compounds. To understand the relative reactivity and oxidation position, electron density (ED) on the nitrogen atom of the studied INDs and relative stability of representative intermediates/products were calculated. It could be confirmed that ED on the nitrogen atom of the INDs is very important in the oxidation of INDs since the ODN reactivity of INDs was enhanced with increasing ED on the nitrogen atom of the investigated INDs. Moreover, theoretical analyses of the relative stability of substrate and intermediates/products (especially for IND) can explain the route for the observed final products in ODN. In other words, oxygen on the nitrogen atom, obtained via the first step of oxidation (electrophilic addition of an active oxygen atom on nitrogen), moves to the nearby carbon atom, because of the relative stability of the intermediates and products.

Application of Metal-Organic Frameworks in Adsorptive Removal of Organic Contaminants from Water, Fuel and Air.

Currently, our environment is contaminated with various toxic substances. Removal of such hazardous materials from water, air and fuel is important for sustainability. In this minireview, adsorptive removal of organic substances, by using metal-organic frameworks (MOFs), for our safe environment will be discussed. For example, removal of (i) pharmaceuticals/personal care products, pesticides, and dyes from water; (ii) S- or N-containing compounds from liquid fuel; and (iii) volatile organic compounds from air will be summarized. Moreover, plausible mechanisms to explain the observation will also be discussed. Finally, prospects in the field will be suggested for further research and development.

Adsorptive removal of hazardous organics from water and fuel with functionalized metal-organic frameworks: Contribution of functional groups.

The purification of contaminated water and fuel is very important for our sustainability. Adsorptive removal has attracted significant attention because of possible applications in industry and the rapid development of metal-organic frameworks (MOFs), which can be competitive adsorbents. In this review, the possible/competitive purification of water (contaminated with organics) and fuel (composed of S- and N-Containing compounds) via adsorption using MOFs, especially those with various functional groups (FGs), will be discussed. The contribution of FGs such as -OH, -COOH, -SO3H, -NH2, and -NH3+ to adsorption/purification will be analyzed in detail, not only to understand the plausible adsorption mechanism but also to utilize specific FGs in adsorption. Moreover, methods for introducing FGs onto MOFs will be summarized. Finally, the prospects for both adsorption/removal and emerging fields will be suggested. Studies for practical applications in industry with shaped MOFs from inexpensive route will be important. The solution pH should be considered for the adsorption of aqueous solution. Applications of MOFs in other fields like storage/delivery and enrichment of analytes might be deeply studied.

Remarkable adsorbent for removal of bisphenol A and S from water: Porous carbon derived from melamine/polyaniline.

Recently, contamination of water resources with various organics such as bisphenols is a problem worldwide. Here, we developed nitrogen-enriched porous carbons (N-PDCs) from pyrolysis of melamine-loaded polyaniline (PANI), for the first time. The N-PDCs and PANI-derived carbons (PDCs, without using melamine) were characterized and applied in adsorptive removal of two typical bisphenols, such as bisphenol A and S (BPA and BPS, respectively), from water under a wide range of conditions. Via this research, we found that one N-PDC (N-PDC-700, obtained at 700 °C) showed very remarkable performances in adsorption of BPA (Q0: 961 mg/g) and BPS (Q0: 971 mg/g) under pH of 7.0. In other words, N-PDC-700 has Q0 value for BPS around 2 times as much as that of the most effective adsorbent, MIL-101-NH2. Moreover, the Q0 value of N-PDC-700 for BPA is the second highest, after the sp2 C dominant N-doped carbon. The plausible adsorption mechanism could be suggested based on the adsorption of BPA under a wide range of pH values. Finally, the N-PDC-700 was easily recycled for several uses, suggesting the potential application in adsorption of bisphenols from water.

Removal of Particulate Matters with Isostructural Zr-Based Metal-Organic Frameworks Coated on Cotton: Effect of Porosity of Coated MOFs on Removal.

Effective removal of particulate matters (PMs) from air is very important for our safe environment, health, and sustainability. In this study, isostructural (with the same topology of fcu) Zr-metal-organic frameworks (Zr-MOFs) such as UiO-66, UiO-67, and DUT-52 (with different porosity) were coated onto cotton and utilized in PM removal from air to understand the contribution of MOFs in improving the performances of air filters. Moreover, UiO-66s with different porosities were also prepared under different conditions from the same reaction mixture. Experiments to remove PMs such as PM2.5 and PM10 showed a critical role of porosity of coated MOFs in the PM removal. Or, the removal efficiency or quality factor increased linearly with the increasing surface area of all the studied MOFs, irrespective of the applied linkers (for synthesizing different MOFs) and synthesis conditions (for different porosities of UiO-66s). Therefore, this work confirms, for the first time, that the porosity of MOF is one of the most important parameters to improve the performance of air filter (to remove PMs) that is modified with coated MOFs. Moreover, we could suggest why porous materials with small pores were effective in capturing PMs (larger in size than pores of porous materials) from air.

Highly Improved Performance of Cotton Air Filters in Particulate Matter Removal by the Incorporation of Metal-Organic Frameworks with Functional Groups Capable of Large Charge Separation.

Currently, air contamination, especially with particulate matters (PMs), is severe in several countries. To increase the efficiency of air filters in PM removal, metal-organic frameworks (MOFs, here, Zr-MOFs, especially with functional groups (FGs) such as -NO2) were coated, after synthesis, onto cotton using covalent bonding for the first time. The removal efficiencies (REs) and quality factors (QFs) of cottons with or without MOFs were in the order: cotton < Zr-MOF/cotton < Zr-MOF-NH2/cotton < Zr-MOF-NH-SO3H/cotton < Zr-MOF-NH3+Cl-/cotton < Zr-MOF-NO2/cotton. This monotonic increase in the PM removal efficiency or QF could be explained with the order of charge separation or developed charges (total, in absolute value: ∼0 to 2.0) on FGs of MOFs. Importantly, Zr-MOF-NO2 coating on cotton showed a very high increase in the performance of cotton in PM removal. QF and RE of Zr-MOF-NO2/cotton were 4.6 times and 6.2 times of the bare cotton, respectively, for PM2.5 removal, even with a very small increase in pressure drop (3 Pa or less) with MOF coating. Based on the research, it can be suggested that coating MOFs on substrates is a promising way to improve the performances of air filters for PM removal, especially when MOFs have FGs that can have large charge separation such as -NO2. This work may pave a way to utilize a functionalized MOF in the effective removal of PMs from air.

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon.

Polyaniline-derived carbon (PDC) was obtained via pyrolysis of polyaniline under different temperatures and applied for the purification of water contaminated with dye molecules of different sizes and charge by adsorption. With increasing pyrolysis temperature, it was found that the hydrophobicity, pore size and mesopore volume increased. A mesoporous PDC sample obtained via pyrolysis at 900 °C showed remarkable performance in the adsorption of dye molecules, irrespective of dye charge, especially in the removal of bulky dye molecules, such as acid red 1 (AR1) and Janus green B (JGB). For example, the most competitive PDC material showed a Q 0 value (maximum adsorption capacity) 8.1 times that of commercial, activated carbon for AR1. The remarkable adsorption of AR1 and JGB over KOH-900 could be explained by the combined mechanisms of hydrophobic, π-π, electrostatic and van der Waals interactions.

Polyaniline-derived carbons: Remarkable adsorbents to remove atrazine and diuron herbicides from water.

The contamination of water resources by hazardous organic compounds is becoming severe worldwide. In this study, the adsorptive removal of atrazine (ATZ) and diuron (DUR), two widely used herbicides, from water by polyaniline-derived carbons (PDCs) was investigated for the first time, under various conditions. A selected PDC, fabricated at optimum conditions, i.e., by pyrolysis at 800 °C (and labeled PDC(800)), showed remarkable adsorptivity for both herbicides, that is, 7.7 and 11.3 times the maximum adsorption capacity (Q0) for ATZ and DUR, respectively, compared to activated carbon (AC). Or, the Q0 values of PDC(800) for ATZ and DUR were 943 and 884 mg/g, respectively; however, the Q0 values of AC were only 123 and 78.0 mg/g, respectively. Moreover, the optimum adsorbent PDC(800) had 4.5 and 3.1 times Q0 that of the best adsorbent, that showed the highest performances, so far, for ATZ and DUR, respectively. Plausible adsorption mechanisms were suggested based on the porosity and the adsorption in a wide pH range. The new adsorbent was reusable via simple solvent washing. Based on its remarkable adsorption performance and facile reusability, PDC(800) can be considered a promising adsorbent to remove herbicides such as ATZ and DUR from contaminated water.

Tungsten Nitride, Well-Dispersed on Porous Carbon: Remarkable Catalyst, Produced without Addition of Ammonia, for the Oxidative Desulfurization of Liquid Fuel.

Polyanilines (pANIs), loaded with phosphotungstic acid (PTA), are pyrolyzed to get WO3 or W2 N (≈6 and ≈7 nm, respectively), which is well-dispersed on pANI-derived porous carbons (pDCs). Depending on the pyrolysis temperature, WO3 /pDC, W2 N/pDC, or W2 N-W/pDCs could be obtained selectively. pANI acts as both the precursor of pDC and the nitrogen source for the nitridation of WO3 into W2 N during the pyrolysis. Importantly, W2 N could be obtained from the pyrolysis without ammonia feeding. The obtained W2 N/pDC is applied as a heterogeneous catalyst for the oxidative desulfurization (ODS) of liquid fuel for the first time, and the results are compared with WO3 /pDC and WO3 /ZrO2 . The W2 N/pDC is very efficient in ODS with remarkable performance compared with WO3 /pDC or WO3 /ZrO2 , which is applied as a representative ODS catalyst. For example, W2 N/pDC shows around 3.4 and 2.7 times of kinetic constant and turnover frequency (based on 5 min of reaction), respectively, compared to that of WO3 /ZrO2 . Moreover, the catalysts could be regenerated in a facile way. Therefore, W2 N/pDC could be produced facilely from pyrolysis (without ammonia feeding) of PTA/pANI, and W2 N, well-dispersed on pDC, can be suggested as a very efficient oxidation catalyst for the desulfurization of liquid fuel.

Effect of Functional Groups of Metal-Organic Frameworks, Coated on Cotton, on Removal of Particulate Matters via Selective Interactions.

Currently, the contamination of air with particulate matters (PMs such as PM2.5 and PM10) is very severe, especially in Asian countries. Metal-organic frameworks (MOFs), with or without extra functional groups such as -NH2 and -NH-SO3H, were coated on conventional cotton to improve the efficiency of filters (composed of cotton fabric) in the removal of PMs from air. More importantly, the effect of the functional group of MOFs on the effective PM removal was analyzed quantitatively for the first time and could be interpreted via selective interactions. The removal efficiency was increased on the order: cotton < UiO-66/cotton < UiO-66-NH2/cotton < UiO-66-NH-SO3H/cotton, and the efficiency of the UiO-66-NH-SO3H-coated cotton was more than three times that of the pristine cotton. Moreover, the quality factor of cotton was more than doubled (or, 2.5-3 times) by UiO-66-NH-SO3H (only 20%) coating. The plausible mechanism for PM removal could be suggested based on the characterization of captured PM and introduced functional groups on MOFs. Based on the removal efficiency, pressure drop, and quality factor, coating of MOFs with functional groups, especially that are effective for charge separations (such as -SO3H), is one of the promising ways to improve the performance of PM filters. Moreover, the suggested strategy might be applied in capturing most of PMs composed of oxides, ammonium species, and carbons with polar outside.