Europium Metal-organic Framework Research Articles

Fast fluorescence sensing of aflatoxin B1 employing a europium metal–organic framework avoiding self-fluorescence interference of target

Aflatoxin B1 (AFB1) easily contaminates grain, oil, and their products, and is strongly carcinogenic. Therefore, rapid, efficient and sensitive detection of aflatoxin plays a key role in the food industry. Here, we prepared a lanthanide metal-organic framework termed Eu-TCPP, in which the ligand can effectively sensitize Eu3+ with excellent photoluminescence properties. It is worth mentioning that the fluorescence intensity of Eu-TCPP is at 617 nm, which can avoid the interferences of AFB1 self-fluorescence emitting in the range of 400 nm–500 nm. Eu-TCPP can efficiently detect AFB1 without using antibody or biomolecular modifications, exhibiting a rapid response of 60 seconds and a limit of detection (LOD) at 11.63 ppb. The Eu-TCPP sensor also has satisfactory performance for determining AFB1 sensitively in real oil samples. In addition, the mechanism of the excellent detection performance of Eu-TCPP has been investigated using density-functional theory (DFT) calculations combined with experimental analysis. The results show that the LUMO energy level of the ligand is higher than that of the aflatoxin, which causes the electrons transfer toward the targets, and results in the reduction of the fluorescence intensity. Therefore, our proposed Eu-MOF materials based on the "antenna effect" have great potential for the development of simple, fast, and sensitive small-molecule sensors, and offer a promising prospect in POCT applications.

Europium Metal–Organic Framework Polymer Composites with Enhanced Luminescence and Selective Ferric Ion Sensing

Europium Metal–Organic Framework Polymer Composites with Enhanced Luminescence and Selective Ferric Ion Sensing

A Water‐Stable Europium Metal‐Organic Framework as a Turn‐Off Fluorescence Sensor for Ascorbic Acid Detection in Human Serum

AbstractAscorbic acid (AA) is a biomarker of some nervous system diseases, whose detection is of significance in many fields. The hydrothermal reaction of naphthalene‐2,6‐dicarboxylic acid (H2NDBC) with Eu3+ produced a europium MOF, Eu‐NDBC. Eu‐NDBC emits the combined emissions from the intraligand charge transfer (ILCT) of NDBC2− ligand and 5D0→7Fj (j=1–4) transfers of Eu(III). The factors of MOF dosage, pH and fluorescence response time are optimized as 0.6 mg, 7.35, and 5 min respectively. The sensitivity test shows a linear fitting equation of I0/I=0.00239 ⋅ CAA+1.03774 (CAA=AA concentration), with its limit of detection calculated as 4.53 μM in a wide linear range of 0–900 μM. The linear fitting of Stern‐Volmer equation gives KSV=2.46×103 M−1 and Kq=4.96×106 M−1 S−1, suggesting Eu‐NDBC sensing AA is a dynamic fluorescence quenching process. Nine control amino acids can't affect Eu‐NDBC sensing AA and the emission intensity stay stable in five fluorescence quenching‐recovery cycles. The returned CAA closed to the set CAA and the recoveries around 100 % support the accurate AA detection by Eu‐NDBC in human serum. Totally, Eu‐NDBC can be regarded as a quantitative turn‐off fluorescence sensor to AA with high sensitivity and selectivity, rapid response and durability.

Formulation of lactoferrin decorated dextran based chitosan-coated europium metal-organic framework for targeted delivery of curcumin

Hepatocellular carcinoma (HPTC) currently ranks as the third leading cause of cancer-related mortality, necessitating an advanced formulation strategy. Recently, lactoferrin (Lf) has been utilized as a specific targeting ligand in HPTC due to its high specificity towards the asialoglycoprotein receptor expressed in cancer cells. Therefore, we present the fabrication of an Lf-decorated carboxymethyl dextran-encased chitosan-coated europium metal-organic framework-based nanobioconjugate (Lf-CMD-CS-CUR@Eu-MOF) for targeted curcumin (CUR) delivery. Briefly, CUR was loaded into Eu-MOF, followed by coating cationic ‘CS’ on the CUR@Eu-MOF surface. Simultaneously, Lf-decorated CMD was prepared via an esterification reaction. Subsequently, Lf-CMD-CS-CUR@Eu-MOF was synthesized using the Maillard reaction. Various spectral characterizations, drug entrapment, drug content, in vitro drug release, biocompatibility and cell cytotoxicity studies were performed. It exhibited an entrapment efficiency of 88.87 ± 2.1 %, a drug content of 3.45 ± 0.98 %, and a drug loading rate of 34.85 ± 0.6 mg/g. Furthermore, the Lf-CMD-CS-CUR@Eu-MOF exhibits excellent biocompatibility with normal cells. The in vitro dissolution study confirmed a release of 78.12 % of ‘CUR’ in pH 5.8 phosphate buffer (over 120 h), attributed to the controlled release rate by the ‘CS’ coating on the surface of CUR@Eu-MOF. The BEL-7402 cell line showed concentration-dependent toxicity of nanobioconjugate to cancerous cells. Therefore, when ‘Lf’ is surface-decorated onto an appropriate polymeric material, it gains the capability to function as a carrier for transporting ‘CUR’ to the precise target site within HPTC. In conclusion, Lf-CMD incorporated CS-coated Eu-MOF can provide a promising approach for targeted drug delivery in HPTC management.

Sensitive electrochemiluminescence immunosensor based on a novel luminescent europium metal–organic framework and antenna effect for detecting pro-gastrin-releasing peptide

Sensitive detection of pro-gastrin-releasing peptide (Pro-GRP) is crucial because it is a highly sensitive and specific tumor marker for small cell lung cancer. Herein, we synthesized an efficient luminescent europium metal–organic framework and developed a sandwich ECL immunosensor for the sensitive detection of Pro-GRP, which used Eu3+ as the central ion and 2,4,6-tri (4-carboxyphenyl)-1,3,5-triazine (H3TATB) as the organic ligand. H3TATB acted as a strong absorbing reagent and transferred its energy to Eu3+ via the antenna effect to enhance the ECL response signal of Eu3+. As per calculations, the ECL efficiency of Eu-TATB, which was a promising ECL luminophore, was up to 130 %. The Cu2O cube worked as a substrate to assist the electron transfer and was used as a co-reaction accelerator to catalyze S2O82− to produce more SO4•− and then enhance the ECL intensity of Eu-TATB. Under optimal experimental conditions, the ECL immunosensor had a linear range of 5 fg mL−1–50 ng mL−1 for detecting Pro-GRP with a detection limit of 1.6 fg mL−1; moreover, it demonstrated excellent stability and specificity and has been successfully applied for detecting Pro-GRP in the human serum.

Dual-mode detection of 2,6-pyridinedicarboxylic acid based on the enhanced peroxidase-like activity and fluorescence property of novel Eu-MOFs.

2,6-Pyridinedicarboxylic acid (DPA) is a significant biomarker of anthrax, which is a deadly infectious disease for human beings. However, the development of a convenient anthrax detection method is still a challenge. Herein, we report a novel europium metal-organic framework (Eu-MOF) with an enhanced peroxidase-like activity and fluorescence property for DPA detection. The Eu-MOF was one-step synthesized using Eu3+ ions and 2-methylimidazole. In the presence of DPA, the intrinsic fluorescence of Eu3+ ions is sensitized, the fluorescence intensity linearly increases with an increase in DPA concentration, and the fluorescence color changes from blue to purple. Simultaneously, the peroxide-like activity of the Eu-MOF is enhanced by DPA, which can promote the oxidation of TMB to oxTMB. The absorbance values increase linearly with DPA concentrations, and the colorimetric images change from colorless to blue. The dual-mode detection of DPA has good sensitivity with a colorimetric detection limit of 0.67 μM and a fluorescent detection limit of 16.67 nM. Moreover, a simple detection method for DPA was developed using a smartphone with the RGB analysis system. A portable kit with standard color cards was developed using paper test strips. The proposed methods have good practicability for DPA detection in real samples. In conclusion, the developed Eu-MOF biosensor offers a valuable and general platform for anthrax diagnosis.

Eu-MOF-Based Fluorescent Ratiometric Sensor by Detecting 3,4,5-Trihydroxybenzoic for Fingerprint Visualization on Porous Objects

Latent fingerprints (LFPs) at the crime scene are served as important clues to locate the trajectory of criminal behavior and portray the characteristics of the suspect. Therefore, visualizing LFPs is of considerable significance. In this work, the europium metal-organic framework (Eu-MOF) sensor was successfully constructed for sensitive detection of gallic acid (3,4,5-trihydroxybenzoic acid, GA) and visualization of the sweat LFPs. The boric-acid-modified Eu-MOF was prepared by using the simple one-pot solvothermal method using Eu as the metal ion center and 3,5-dicarboxybenzeneboronic acid (BBDC) as the organic ligand. The sensor showed desirable photoluminescent performance through the chelating of BBDC with Eu3+. The sensor exhibited the satisfactory linear relationship to GA in the range of 1 nM to 20 nM with a low detection limit of 0.34 nM under the optimized conditions. The prepared sensor with ideal selectivity to GA was successfully applied for visualizing LFPs on porous substrates with the high contrast and superior stability. Given the good performance of the sensor, all fingerprint images obtained from 1 200 samples presented clear friction ridges and met the identification criteria. Notably, the sensor had less impact on the subsequent deoxyribonucleic acid (DNA) detection, displaying a promising perspective for applications in extracting physical evidence of site investigation.

Metal-organic framework integrated hydrogel bioreactor for smart detection of metal ions

Bioreactors with environment responsiveness for smart detection has attracted widespread interest. Bioreactors that operate in liquid have excellent reaction speed and sensitivity, and those that operate at a solid interface have unique portability and stability. However, bioreactors that can simultaneously take advantage of both properties are still limited. Here, we developed a metal-organic framework (MOF) integrated hydrogel bioreactor that can accommodate both solid and liquid properties by using a hydrogel as a quasi-liquid medium. To enhance the stability and intelligence of the hydrogel bioreactor, we have opted for the utilization of europium metal-organic framework (Eu-MOF) as the optical output to withstand long-term storage challenges, and DNA as the highly programmable substance for intelligent target response. On this basis, smart detection of metal ions and biological micro-molecules have been achieved. Notably, this quasi-liquid hydrogel bioreactor has effectively tackled the intrinsic issues of inadequate dispersion stability of Eu-MOF in liquid systems and poor stability of DNA against environmental interference. Moreover, this MOF integrated hydrogel bioreactor has been applied to the construction of a portable hydrogel bioreactor, which enables platform-free and arrayed target detection via a smartphone, providing a new perspective for further promoting the application of quasi-liquid hydrogel bioreactors and intelligent nanobiological sensors.

A Europium Metal-Organic Framework and Its Polymer Composite Membrane as Switch-Off Fluorescence Sensors for Antibiotic Detection in Lake Water.

The detection of antibiotic residues is of great significance in monitoring their overuse in healthcare, livestock and poultry farming, and agricultural production. Herein, EuCl3 and 4,4'-dicarboxyl-diphenoxyethene (H2DPOE) ionothermally reacted in 1-methyl-3-butylimidazolium chloride to give a europium metal-organic framework (Eu-DPOE). Eu-DPOE shows different fluorescence quenching rates for sensing eight antibiotics under different excitation wavelengths. Eu-DPOE displays a fast response, high selectivity, and sensitivity in antibiotic detection by fluorescence quenching. Eu-DPOE can sensitively detect TCs (tetracyclines), NOR (norfloxacin), NFT (furazolidone), ODZ (ornidazole), SDZ (sulfadiazine), and CHL (chloramphenicol) with limits of detection below 0.5 μmol/L. It provides a convenient and rapid tool for sensing antibiotics in aqueous solution. The detection mechanism is a competition absorption between DPOE2- and antibiotics with the supports from powder X-ray diffraction (PXRD), UV-vis spectra, and fluorescence lifetime. With a composite membrane of poly(vinylidene fluoride) (PVDF) matrix loading Eu-DPOE (Eu-DPOE@PVDF), Eu-DPOE@PVDF exhibits a visual fluorescence response to NOR under a 254 nm UV lamp and NFT and CTC under 365 nm. Eu-DPOE@PVDF is applied in the quantitative detection of CTC, NOR, and NFT in lake water with recovery rates ranging from 88.37 to 113.8%. Totally, fluorescence-quenched Eu-DPOE@PVDF exhibits a fast response, high selectivity, and sensitivity in sensing CTC, NOR, and NFT.

Europium metal-organic frameworks: Synthesis, characterization, and application as fluorescence sensors for the detection of Cu2+, Ni2+ cations and T3, T4 hormones

The solvothermal approach was used to create a novel Eu metal-organic framework (Eu-MOF) based on 1,4-benzendicarboxylic acid (TPA), 1,10-phenanthroline, and N,N-dimethylformamide (DMF)/H2O. Structural analysis of Eu-MOF, Fluorescence spectrometry, Fourier Transform Infrared Spectrometer (FTIR), Scanning Electron Microscopy (SEM), Energy dispersive X-ray (EDX) mapping, Thermo-gravimetric analysis (TGA), and Single Crystal X-Ray Diffraction (PXRD) methods. Using the fluorescence properties of the synthesized Eu-MOF, its use as a fluorescence sensor in the determination of different analytes, such as organic molecules (T3-T4 hormone, ascorbic acid, and glucose) and metal ions (Na+, K+, Ca2+, Mg2+, Cu2+, Mn2+, Hg2+, Pb2+, Ni2+, Cr3+, Al3+, Fe3+), was investigated. Fluorescence experiments revealed that Cu2+, Ni2+ cations, as well as T3 and T4 hormones, quenched the fluorescence of Eu-MOF. Turn-off luminescence can be induced by 10 μM Cu2+, 30 μM Ni2+ cations, 500 nM T3, and 800 nM T4 hormones. Fluorescence quenching efficiencies were calculated for Cu2+, Ni2+, T3, and T4 99.7%, 99.6%, 98.7%, and 98.2%, respectively.

A smartphone-based visual ratiometric fluoroprobe for rapid and sensitive detection hypochlorous acid based on dual-emission metal organic frameworks

Herein, we designed/developed a mixed fluorescence system with europium metal-organic framework (EDB) and zinc metal-organic framework (ZBNB). At the 270-nm excitation wavelength, the EDB-ZBNB dually emitted at 425 and 615 nm and displayed blue solution under 365-nm UV lamp. When HOCl was fortified, the 425-nm blue emission dropped progressively, while the 615-nm red emission was relatively stable. Upon addition of ClO−, the shortened fluorescence lifetime demonstrated that the quenched 425-nm fluorescence of ZBNB was owing to the occurrence of dynamic quenching effect. Besides, amino groups are protonated in water to form -NH3+, which interact with ClO− to form hydrogen bonds, reduce the distance between -NH3+ and ClO−, produce energy transfer and result in fluorescence quenching. The ratiometric fluoroprobe provided a significant color change from blue to red, making HOCl detection visual and rapid. This fluorescent probe overcome the disadvantage of conventional redox-based fluorescent probes that can be interfered by MnO4− and other oxidants with stronger oxidizing capacity than free ClO−. Furthermore, a smartphone-based portable sensing platform was developed based on EDB-ZBNB. By using a “Thingidentify” software on smartphone, the sensing platform was used to detect HOCl in waters with a low detection limit of 28.0 nM and the fortified recoveries of 98.87–103.60%. Thus, this study provides a novel and promising platform for the detection of free ClO− in monitoring water quality.

An intelligent smartphone-test strip detection platform for rapid and on-site sensing of benzoyl peroxide in flour samples

Benzoyl peroxide (BPO) is a commonly used flour whitener, but its excessive usage can have adverse effects on human health, such as nutrient loss, vitamin deficiencies and certain diseases. In this study, a europium metal organic framework (Eu-MOF) fluorescence probe was prepared, which exhibited a strong fluorescence emission at 614 nm upon excitation at 320 nm, with a high quantum yield of 8.11%. The red fluorescence of the probe could be effectively quenched by BPO through the inner filter effect (IFE) and photoinduced electron transfer (PET) mechanism. The detection process offered several advantages, including a wide linear range of 0–0.95 mM, a low detection limit of 66 nM and a fast fluorescence response of 2 min. Furthermore, an intelligent detection platform was designed to enhance the practical application of the detection method. This platform combined the portability and visuality of a traditional test strip with the color recognition capability of a smartphone, allowing for the visualization and quantitative detection of BPO in a convenient and user-friendly manner. The detection platform was successfully applied to the analysis of BPO in real flour samples with satisfactory recoveries (99.79%–103.94%), suggesting a promising strategy for the rapid and on-site detection of BPO in food samples.

Facile synthesis of 2D Europium-metal organic frameworks nanosheets for highly efficient electrochemiluminescence in DNA detection

Lanthanide metal organic frameworks (Ln-MOFs) with self-luminous behavior are considered promising emitters of electrochemiluminescence (ECL) due to their unique antenna effects. In this study, the novel 2D Europium-metal organic frameworks (Eu-MOFs) nanosheets were synthesized by simply blending 1, 10-phenanthroline-2, 9-dicarboxylic acid (PDA) and Eu salts at room temperature. When N, N-diethylethylenediamine (DEAEA) was used as the efficient co-reactant, the 2D Eu-MOFs exhibited stronger and steadier ECL performance compared with 2D Europium-metal organic gels (Eu-MOGs) synthesized using similar steps, due to their rigid skeletons and higher crystalline degree, which facilitated electron transfer. In addition, we designed a switching mode ECL biosensor, which was combined with an exonuclease-assisted DNA walker cycling signal amplification strategy, enabled the ultra-sensitive detection of the I27L gene, which was significantly associated with an increased risk of maturity-onset diabetes of the young (MODY). When the target DNA was present, DNA walker recycle amplification occurred driven by exonuclease III (Exo III). Subsequently, the ECL intensity of the system was reduced by introducing the ferrocene-labeled probe (H2-Fc) as a signal quencher. Under the optimal experimental conditions, a wide detection linear range of the target DNA was observed from 1 fM to 10 nM with a low detection limit of 447 aM. This research provided new possibilities for a gentle and simple method to obtain 2D MOFs with stable ECL signals for the sensitive detection of specific DNA sequences.

Ratiometric fluorescence and visual sensing of ATP based on gold nanocluster-encapsulated metal-organic framework with a smartphone

Adenosine triphosphate (ATP) plays an important role in various biological processes and the ATP level is closely associated with many diseases. Herein, we designed a novel dual-emissive fluorescence nanoplatform for ATP sensing based on red emissive europium metal-organic framework (Eu-MOF) and blue emissive gold nanoclusters (AuNCs). The presence of ATP causes the decomposition of Eu-MOF owing to strong affinity of Eu3+ with ATP. As a result, the red emission of Eu-MOF decreases while the blue emission of AuNCs remains unchanged. The distinct red/blue emission intensity change enables the establishment of a ratiometric fluorescent and visual sensor of ATP. Moreover, a fluorescent paper-based sensor was fabricated with the ratiometric ATP probes, which enabled easy-to-use and visual detection of ATP in serum samples with a smartphone.

Fluorescent Sensing of Ciprofloxacin and Chloramphenicol in Milk Samples via Inner Filter Effect and Photoinduced Electron Transfer Based on Nanosized Rod-Shaped Eu-MOF.

Rapid, facile, and accurate detection of antibiotic residues is vital for practical applications. Herein, we designed a sensitive, visual, and rapid analytical method for sensitive detection of ciprofloxacin and chloramphenicol based on a nanosized rod-shaped Europium metal organic framework (Eu-MOF). The fluorescent Eu-MOF was firstly synthesized by a simple synthetic route at room temperature, which displays a red emission. The mechanisms of detecting ciprofloxacin and chloramphenicol were confirmed to be the inner filter effect (IFE) and photoinduced electron transfer (PET). Under the optimized experimental conditions, the detection limits of the developed method for ciprofloxacin and chloramphenicol detection were 0.0136 and 3.16 μM, respectively. Moreover, the sensor was effectively applied for quantitative determination of ciprofloxacin and chloramphenicol milk samples with satisfactory recoveries of 94.5–102% and 97–110%, respectively. This work developed a new method for rapid detection of ciprofloxacin and chloramphenicol residues. In addition, the established method has potential practical application value for on-site safety regulation on antibiotic residues in animal-derived food.

Self-Powered UVC Photodetector Based on Europium Metal-Organic Framework for Facile Monitoring Invisible Fire.

The effective use of a europium metal-organic framework (Eu-MOF) as a photoabsorber material has been reported. Using the advantages of Eu-MOFs including simple preparation, wide bandgap structure, and stability in the environment, a self-powered and high UVC-selectivity detector based on Eu-MOF nanoparticles was prepared with a simple device geometry. The as-fabricated photodetector was highly sensitive to 254 nm UV illumination without an external power supply. Accordingly, it exhibited a high UVC-to-UVA rejection ratio (I254/I365 ≈ 40) and UVC-to-solar rejection ratio (I254/Isolarlight ≈ 34), a fast response time of 98/122 ms, a comparable on/off photocurrent ratio (107.33), and superior stability. The self-powered Eu-MOF photodetector can detect and monitor UV emission from an invisible fire in an early state at room temperature, suggesting practical use as a potential optoelectronic device.

A water-stable Eu-MOF as multi-responsive luminescent sensor for high-efficiency detection of Fe3+, MnO4− ions and nicosulfuron in aqueous solution

Effective detection of contaminants in water, such as pesticides, excess Fe3+ and MnO4−, is critical to human health and environmental protection. They can be quantitatively detected by a new luminescent sensor based on a water stable europium metal-organic framework (Eu-MOF). The dual nucleus Eu-MOF is connected by L6−ligands through μ6: η1, η2, η3, η3, η4, η5 coordination to form a 2D wavy network, and then expands into a three-dimensional structure through ligand L6− connection. Due to its high water stability and multiple emission centers, the Eu-MOF can be used as luminescence sensors for pollutants in water. Eu-MOF exhibits high selectivity for Fe3+, MnO4−, and nicosulfuron (NSF) in water through luminescence quenching with low detection limit, and fast response, indicating that Eu-MOF is a reliable analysis platform for multi-responsive sensing.

A boric acid functional multi-emission metal organic frameworks-based fluorescence sensing platform for visualization of gallic acid

Gallic acid (GA) is widely applied as antioxidant in food, beverages, health-care products, as well as medicines, quantification detection of GA is essential for human health and quality control in food, drugs and health-care products. Herein, we designed a portable sensing platform by utilizing multi-emission Europium Metal-Organic Frameworks (Eu-MOFs) fluorophore which constructed by the coordination polymerization of europium ions (Eu3+) with 3,5-Dicarboxybenzeneboronic acid (BBDC) for the visual detection of GA. The Eu-MOFs fluorophore displayed red fluorescence with the emission peaks at 454 nm and 615 nm under 270 nm excitation. With the addition of GA, the special covalent structure of the borate ester formed between the phenolic hydroxyl group of benzene ring with the hydroxyl group of the boric acid. The red emission at 615 nm decreased, while the blue emission at 454 nm increased gradually. The highly colorimetric fluorescence provides a significant color change from red to blue and furtherly improves the detection precision, resulting in a visual and rapid detection of GA with a limit of detection (LOD) of 22.0 nM. Furthermore, the Eu-MOFs fluorescent probe applied for visual and quantitative detection of GA combined with smartphone color recognizer in tea and fruit juice samples with the recovery range of 88.34–101.16 %, and the detection results were consistent with high performance liquid chromatography (HPLC) results, which suggest an effective strategy to monitor the food additives for food safety and health guarantee.

Fluorescent lanthanide metal-organic framework for rapid and ultrasensitive detection of methcathinone in human urine

Methcathinone (MC), a new and easily abused psychoactive substance, not only has a rigorous impact on public security, but also endangers people's health. Herein, novel fluorescent europium metal-organic frameworks (Eu-MOF) were synthesized through a facile one-step solvothermal strategy and utilized as an effective “signal-off” sensing platform for rapid and ultrasensitive detection of MC. The as-fabricated Eu-MOF possessed superior optical properties encompassing bright red fluorescence and good photostability. In the presence of MC, the fluorescence of Eu-MOF was significantly quenched, mainly attributing to the internal filtering effect between Eu-MOF and MC. The fluorescent signal showed high selectivity for MC over other illicit drugs, and offered two linear ranges of 1–100 ng/mL and 100–4000 ng/mL with a detection limit of 0.40 ng/mL. Strikingly, the nanoprobe could be applied for the assay of MC in human urine with satisfactory recoveries and acceptable results. This work provides a promising route for MC detection to effectively control illicit drug pandemic worldwide.

Metal-organic frameworks of rare earth metals embedded side-by-side nanofiber as a switchable luminescent sensor for Fe3+ and Cu2+ in aqueous media

Europium metal-organic frameworks (Eu-MOFs) and terbium metal-organic frameworks (Tb-MOFs) incorporated side-by-side nanofibrous membrane (Eu//Tb SBS NFs) was successfully fabricated by electrospinning. Eu-MOFs or Tb-MOFs emitting red or green light, respectively, were adjusted on each side, and a luminescent sensor with yellow luminescence was prepared by adjusting the ratio of the two MOFs. Eu//Tb SBS NFs have high luminescence efficiency and show sequential changes in luminescence color (yellow-green-gray). To investigate whether it is possible to detect metal ions reliably in aqueous media, we evaluated the wettability of the samples by contact angle measurement and luminescence stability in different pH conditions. Eu//Tb SBS NFs showed selective detection of Fe3+ and Cu2+ in aqueous solutions containing various metal ions. The quenching effect constant (Ksv) for Fe3+ was calculated as 7.62 x 103 M−1 (the limit of detection = 1.6 x 10−7 M), indicating high sensitivity for Fe3+. The luminescence changes of the Eu//Tb SBS NFs resulting from the presence of the metal ions and varying concentrations of the targeted metal ions were confirmed with the naked eye. This is the first report of a nanofibrous membrane with a unique side-by-side structure designed as a luminescence switchable dual sensor for Fe3+ and Cu2+. The superiority of Eu//Tb SBS NFs as luminescent sensors is discussed in this paper.