Detection Of Cu2 Research Articles

Electrochemical detection of copper(II) in environmental samples using Penicillium sp. IITISM_ANK1 based biosensor

Detection of toxic metals at the lowest of their concentration in a variety of matrices has become a necessity due to the widespread and persistent nature of the contaminant. In this context, biosensors provide a viable alternative to the large sophisticated instrumentation. This study focuses on the development of a cost-effective fungal biomass-based biosensor that can be used for the detection of Cu(II). The fungal cells were pretreated with formaldehyde and studied with various spectroscopic studies. It was observed that the carbonyl groups along with amine groups played role in the sorption of copper ions which were stripped in an electrolytic solution to quantify the metal. Herein the dried fungal biomass was chemically activated and used to prepare a novel graphite paste electrode by repurposing a plastic pipette tip. The factors affecting the detection signal were optimized in further study. The electrochemical characterization revealed that the prepared bio-electrode was capable of detecting Cu in the range of 1 × 10−7 M to 2 × 10−5 M.

Quaternized salicylaldehyde Schiff base side-chain polymer-grafted magnetic Fe3O4 nanoparticles for the removal and detection of Cu2+ ions in water

In this study, quaternized salicylaldehyde Schiff base side-chain polymer grafted magnetic Fe3O4 nanoparticles (Fe3O4@SiO2-PAP) were formed via the surface-initiated reversible addition-fragmentation chain-transfer polymerization of 2-(dimethylamino)ethyl methacrylate, subsequent quaternization with 5-chloromethylsalicylaldehyde and Schiff condensation with 2-aminophenol. The prepared nanohybrid was characterized by scanning and transmission electron microscopes, Fourier transform infrared spectroscopy, X-ray diffractometer, vibrating sample magnetometer and X-ray photoelectron spectroscopy. Fe3O4@SiO2-PAP was found to disperse well in water due to the strong hydrophilicity of the immobilized polymer. Cu2+ ion adsorption by the nanohybrid followed both pseudo-second-order kinetic and Langmuir isotherm models, and a maximum adsorption capacity of 59.98 mg/g was attained, with good repeatability. In addition, the nanohybrid exhibited significant and sensitive fluorescence quenching characteristics after capturing Cu2+ ions in water with good selectivity among the other studied cations. The fluorescence detection linear range was 0.1–2 mg/L, with the lowest detection limit measured as 0.125 μmol/L. Moreover, the nanohybrid exhibited high reusability for Cu2+ ion adsorption and sensing applications. Finally, the interaction of grafted Schiff base ligand with Cu2+ ions was analyzed using theoretical calculations. Consequently, the developed nanohybrid offers a new pathway for the removal and detection of Cu2+ ions in water.

Lanthanide(III)-Modified MIL-125(Ti-Ln) (Ln = Eu or Tb) for the Detection of Cu(II) and Fe(III) Ions

Lanthanide(III)-Modified MIL-125(Ti-Ln) (Ln = Eu or Tb) for the Detection of Cu(II) and Fe(III) Ions

Molecularly Designed Ion-Imprinted Nanoparticles for Real-Time Sensing of Cu(II) Ions Using Quartz Crystal Microbalance.

A molecularly designed imprinting method was combined with a gravimetric nanosensor for the real-time detection Cu(II) ions in aqueous solutions without using expensive laboratory devices. Thus, 1:1 and 2:1 mol-ratio-dependent coordination modes between Cu(II), N-methacyloly-L histidine methyl ester (MAH) functional monomer complexes, and their four-fold and six-fold coordinations were calculated by means of density functional theory molecular modeling. Cu(II)-MIP1 and Cu(II)-MIP2 nanoparticles were synthesized in the size range of 80-100 nm and characterized by SEM, AFM and FTIR. Cu(II)-MIP nanoparticles were then conducted to a quartz crystal microbalance sensor for the real-time detection of Cu(II) ions in aqueous solutions. The effects of initial Cu(II) concentration, selectivity, and imprinting efficiency were investigated for the optimization of the nanosensor. Linearity of 99% was obtained in the Cu(II) ion linear concentration range of 0.15-1.57 µM with high sensitivity. The LOD was obtained as 40.7 nM for Cu(II)-MIP2 nanoparticles. The selectivity and the imprinting efficiency of the QCM nanosensor were obtained significantly in the presence of competitive ion samples (Co(II), Ni(II), Zn(II), and Fe(II)). The results are promising for sensing Cu(II) ions as environmental toxicants in water by combining molecularly designed ion-imprinted nanoparticles and a gravimetric sensor.

An open-source handheld spectrometer for colorimetric and fluorescence analyses

Spectrometers are essential analytical devices for analyzing fluid samples in biological, environmental, and disease diagnostic applications. However, the relatively high cost, the lack of portability, and the requirement for a constant power supply of bulky laboratory instruments limit their on-site applications. Herein, a wireless, cost-effective, open-source, and handheld spectrometer was designed and fabricated to realize the colorimetric and fluorescence analyses. It was built from off-the-shelf electronics utilizing 3D printing technology. The assembled device costs as little as $50. It has an overall dimension of 5 × 5 × 8 cm and an overall weight of only 130 g, which can easily fit in the palm of an adult's hand. It can detect light waves in the 405–690 nm range and transmit the read data to the corresponding SpecAnalysis Android application via Bluetooth. The feasibility of the device was demonstrated by the optical detection of Cu(II), bovine serum albumin, and calf thymus DNA. The sensitivity and detection limits of this device were comparable to those of commercial research-grade spectrophotometers and fluorescence spectrometers. The results suggest that the handheld spectrometer can be applied to detect a variety of substances, not limited to quantitative analysis of a specific individual compound.

A new lipophilic cationic rhodamine-based chemosensor for detection of Al(III)/Cu(II) and intracellular pH change and its application as a smartphone-assisted sensor in water sample analysis

A new probe, RTPP was prepared by condensation of rhodamine B hydrazide with (3-formyl-4-hydroxybenzyl)triphenylphosphonium chloride. The structure of sensor RTPP was elucidated using spectroscopic methods and single crystal X-ray diffraction. Colourless and non-fluorescence sensor RTPP solution turns pink in the presence of Cu2+ and showed orange fluorescence enhancement in the presence of Al3+. Cation recognition performance and binding mechanisms of the probe were studied through UV, fluorescence, IR, MS, and NMR spectroscopic studies; where the results revealed that sensor RTPP has a high affinity towards Al3+/Cu2+ with the limit of detection down to at least 10-7 M. The developed system was applicable for tracing Cu2+ through colorimetric method in two selected water samples with satisfactory results. More significantly, “naked-eye” detection of Cu2+ using RTPP has been effectively incorporated with a smartphone RGBColorDetector application to make it suitable for on-site qualitative and quantitative colorimetric investigation. In addition, RTPP can act as a sensor for detecting acidic pH change in HCT 116 human colorectal carcinoma cell line through fluorescence response.

Fabrication of hydrophilic luminescent zinc oxide quantum dots for selective detection of copper ions and efficient inhibition of harmful fungi

In this study, we have successfully prepared surface modified zinc oxide quantum dots (M-ZnO QDs) with ultra-stable fluorescence and excellent hydrophilicity through introducing (3-aminopropyl)triethoxysilane (APTES). The as-prepared M-ZnO QDs under the optimum condition presented strong yellow fluorescence emission under 355 nm excitation and showed satisfied reproducibility. Physical and chemical properties of the synthesized ZnO QDs were further studied by various characterization techniques. Transmission electron microscopy showed homogeneous distribution of spherical M-ZnO QDs with the average particle size of 4.03 nm. According to the characteristic that metal ions can quench fluorescence, M-ZnO QDs-based fluorescence sensor for the detection of Cu 2+ in aqueous solution is developed in this work, which has the advantages of excellent selectivity, good sensitivity and a wide linear range. The limit of detection was 0.51 μM and the linear detection range was 1–200 μM for Cu 2+ determination. The practicability of the fluorescent probe is further validated in the lake water and the satisfactory spiked recoveries of Cu 2+ ranges from 99.1 % to 108.8 %. Besides, M-ZnO QDs displayed concentration inhibition effect and strain effect on the growth of fungi. Thus, the as-prepared M-ZnO QDs are demonstrated to be promising for Cu 2+ determination and anti-fungal applications.

Multi-targeted fluorescent probes for detection of Zn(II) and Cu(II) ions based on ESIPT mechanism

With the rapid development of industry, it is pretty critical to detect the heavy metals. Recently, the 2-(2-hydroxyphenyl) benzothiazole derivatives with different numbers of rotatable phenyl m (m = 1,2,3) fluorescent probes HLm were synthesized. However, the theoretical analysis of the mechanism was still missing. In this work, we have systematically researched the mechanisms of excited state intramolecular proton transfer (ESIPT) and the detection of Cu(II), Zn(II) ions for the hydrogen-bond system HLm though quantum chemistry methods. By bond parameters and the minimum energy pathways analyses, the proton of this system was probed directly transfer without barrier. Bond parameters, real space function at bond critical point, the frontier molecular orbital, electron spectra and orbital interaction diagram were carried to elucidate response to Cu(II), Zn(II) ions. In addition, comparing the Gibbs free energy variation of the complexation reaction between fluorescent probes and ions, it can be proved that the number of rotatable benzene rings affects the response ability of the probe to target ions.

3-Aminopyridine Salicylidene: A Sensitive and Selective Chemosensor for the Detection of Cu(II), Al(III), and Fe(III) with Application to Real Samples.

Interest in developing selective and sensitive metal sensors for environmental, biological, and industrial applications is mounting. The goal of this work was to develop a sensitive and selective sensor for certain metal ions in solution. The goal was achieved via (i) preparing the sensor ((E)-2-((pyridine-3-ylimino)methyl)phenol) (3APS) using microwave radiation in a short time and high yield and (ii) performing spectrophotometric titrations for 3APS with several metal ions. 3APS, a Schiff base, was prepared in 5 min and in a high yield (95%) using microwave-assisted synthesis. The compound was characterized by FTIR, XRD, NMR, and elemental analysis. Spectrophotometric titration of 3APS was performed with Al(III), Ba(II), Cd(II), Co(II), Cu(II), Fe(III), Mn(II), Ni(II), and Zn(II). 3APS showed good abilities to detect Al(III) and Fe(III) ions fluorescently and Cu(II) ion colorimetrically. The L/M stoichiometric ratio was 2:1 for Cu(II) and 1:1 for Al(III) and Fe(III). Low detection limits (μg/L) of 324, 20, and 45 were achieved for Cu(II), Al(III), and Fe(III), respectively. The detection of aluminum was also demonstrated in antiperspirant deodorants, test strips, and applications in secret writing. 3APS showed high fluorescent selectivity for Al(III) and Fe(III) and colorimetric selectivity towards Cu(II) with detection limits lower than corresponding safe drinking water guidelines.

A 1,3,4-thiadiazole functionalized Schiff base based fluorescence enhancement and colorimetric probe for detection of Cu (II) ion and its potential applications

A fluorescence enhancement probe XS-1 based on coumarin, 1,3,4-thiadiazole and Schiff base cores was synthesized for detection of Cu2+ via the CN bond hydrolysis reaction. Furthermore, Cu2+ ion induced ‘turn-on’ fluorescence emission was preserved in the presence of other competing ions which clearly suggests the high selectivity and anti-interference. In addition, remarkable changes of solution color from light pink to bright yellow and fluorescence color from colorless to bright green realized the visual detection of Cu2+ by naked eyes. The excellent characters and low detection limit (0.17 μM) enabled its application of Cu2+ detection in actual water samples and organisms/living cells. Systematic investigations were also conducted to demonstrate the behavior of XS-1 to Cu2+ ion by the help of 1H NMR titration, HRMS titration and DFT calculations.

Oxidation state-specific fluorescent copper sensors reveal oncogene-driven redox changes that regulate labile copper(II) pools

Copper is an essential metal nutrient for life that often relies on redox cycling between Cu(I) and Cu(II) oxidation states to fulfill its physiological roles, but alterations in cellular redox status can lead to imbalances in copper homeostasis that contribute to cancer and other metalloplasias with metal-dependent disease vulnerabilities. Copper-responsive fluorescent probes offer powerful tools to study labile copper pools, but most of these reagents target Cu(I), with limited methods for monitoring Cu(II) owing to its potent fluorescence quenching properties. Here, we report an activity-based sensing strategy for turn-on, oxidation state-specific detection of Cu(II) through metal-directed acyl imidazole chemistry. Cu(II) binding to a metal and oxidation state-specific receptor that accommodates the harder Lewis acidity of Cu(II) relative to Cu(I) activates the pendant dye for reaction with proximal biological nucleophiles and concomitant metal ion release, thus avoiding fluorescence quenching. Copper-directed acyl imidazole 649 for Cu(II) (CD649.2) provides foundational information on the existence and regulation of labile Cu(II) pools, including identifying divalent metal transporter 1 (DMT1) as a Cu(II) importer, labile Cu(II) increases in response to oxidative stress induced by depleting total glutathione levels, and reciprocal increases in labile Cu(II) accompanied by decreases in labile Cu(I) induced by oncogenic mutations that promote oxidative stress.

Direct electrochemical detection of Cu(Ⅱ) ions in juice and tea beverage samples using MWCNTs-BMIMPF6-Nafion modified GCE electrodes

Due to a small amount of Cu (Ⅱ) ions being beneficial and too much being harmful, it is necessary to establish a rapid and direct detection method. Herein, we reported a platform based on multiwalled carbon nanotubes (MWCNTs), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), and Nafion solution-modified glassy carbon electrode (GCE) for the direct electrochemical detection of Cu (II) ions. We used differential pulse anodic stripping voltammetry, including the electrodeposition of Cu (Ⅱ) ions on the modified GCE and subsequent anodic stripping. Under the optimum conditions, the linear range was 20 μg·L−1 ∼ 950 μg·L−1, the limit of detection (LOD) was 16 μg·L−1, and the limit of quantification (LOQ) was 54 μg·L−1 for Cu (II). We realized the quantitative detection of Cu (Ⅱ) ions in juice and tea beverage without tedious pretreatment. The result showed that the sensor had good anti-interference and practicability for actual food samples.

Thermocapillary convection modulating ion migration for rapid recognition and detection of Cu (Ⅱ) based on MnO2 NSs-AuNSs modified screen printed electrode

Microfluidic chip for sensing heavy metal ions has been strongly attended due to its merits, but still remains a large challenge from long analysis time derived from the preconcentration process of metal ions. Herein, a heated flow channel was manufactured by 3D printing combined with a filter paper to construct a microfluidic chip, the thermocapillary convection strategy was introduced to accelerate ions migration, allowing for rapidly recognizing metal ions. The MnO2 nanosheets-Au nanostars (MnO2 NSs-AuNSs) film was employed as modifier to fabricate a flexible screen printed electrode (SPE) for high-efficiency detecting metal ions based on thermocapillary convection accelerating accumulation method. To verify the proposed strategy, the detection of Cu2+ was chosen as a model. The results revealed that the proposed strategy possessed a rapid detection to Cu2+, which greatly improved the detection efficiency (saved 400 s of preconcentration time) and achieved a detection limit down to 0.0270 ppb. Interestingly, the constructed method was successfully used to evaluate Cu2+ concentration in sweat samples with satisfactory results. This proposed method maybe provide new insight to develop a novel approach to rapidly and sensitively detect metal ions, which possess huge utilization potentiality for safeguarding human health.

Glycine mediated colorimetric method along with image analyses algorithms for detection of Cu (II) in water

In the present work, glycine mediated simple colorimetric method has been reported for the detection of Cu (II) in water. The addition of glycine in a colorless Cu (II) contaminated water sample imparts bluish color due to the formation of ligand to metal charge transfer (LMCT) complex. The Cu (II) concentrations (0.1–5 mM) dependent color intensity has been verified through visual detection and UV–vis light absorption characteristics. The data obtained from UV–vis spectroscopy is employed further to estimate the formation constant of Cu (II)-glycine complex. RGB profile based image analysis algorithms are used to discriminate the color of Cu (II)/glycine solutions. The images corresponding to 1–4 mM Cu (II) solutions show systematic linear variations in RGB profiles after addition of glycine. Present study provides an insight towards exploring the possibilities of simple image analysis for quantitative estimation of Cu (II) solutions along with visual detection and spectroscopic based colorimetric technique.

Vanillin based colorimetric and fluorometric chemosensor for detection of Cu(II) ion: DFT calculation, DNA / BSA interaction and molecular docking studies

• Vanillin based chemosensor ligand VNP has been designed and synthesized. • The ligand VNP can recognize Cu 2+ ion by colorimetric and fluorometric method. • The ligand VNP and VNP-Cu complex molecular structures are optimized by using DFT calculation. • The binding studies of ligand VNP with biomolecules like DNA, BSA and HSA are performed. • The interaction between the ligand VNP and biomolecules are confirmed by molecular docking studies. Vanillin based Schiff base ligand VNP was designed and synthesized which was used to study the calorimetric detection of Cu 2+ by a colour change from colourless into pink in the presence of other metal ions like Co 2+ , Ni 2+ , Zn 2+ , Pb 2+ , Hg 2+ , Sr 2+ , Cd 2+ , Ca 2+ , Na + , K + , Al 3+ and Cr 3+ in CH 3 CN/H 2 O (9/1, v/v) mixture. Similarly, the ligand VNP also exhibited fluorometric detection of Cu 2+ by “turn-off” process when compared with other metal ions which do not show any notable spectral changes. The ligand VNP is coordinated with Cu 2+ which results the formation of the VNP-Cu complex has the binding stoichiometric ratio at 1:1 as determined by ESI-MS, as well as job’s plot analysis and it was further explained by the CHEQ mechanism. The optimized geometry of the VNP and VNP-Cu complex was analysed by DFT methods, which results confirms the formation of the VNP-Cu complex. The detection range for the Cu 2+ is 2.34 μM. Furthermore, the effective interaction of VNP with the various biomolecules (BSA, HSA and DNA) has been analyzed by absorption and emission spectroscopic techniques. The obtained results were clearly indicates that the interaction between the VNP and biomolecules have better binding ability and which is confirmed by molecular docking studies.

NH2-MIL-125(Ti) nanoparticles decorated over ZnO microrods: An efficient bifunctional material for degradation of levofloxacin and detection of Cu(II)

The evolution of MOF/metal oxide composites has recently been recognized as excellent photocatalysts and sensors establishing the door for research into the treatment and detection of toxic contaminants from an aqueous phase. The decoration of MOF nanoparticles onto the surface of ZnO microrods with substantial benefits was significantly studied in the current study. Herein, we have developed NH2-MIL-125(Ti)/ZnO heterostructure as a dual functional platform for the degradation of levofloxacin (LVX) as well as detection of Cu(II) ions. The heterostructure was fabricated by a simple ultrasonic-assisted hydrothermal method followed by numerous characterizations. NH2-MIL-125(Ti)/ZnO-(II) showed an average crystallite size of 47.64 nm, surface area of 39.508 m2/g, and band gap of 2.98 eV. The morphological studies revealed the deposition of NH2-MIL-125(Ti) nanoparticles on ZnO microrods in high density. Under solar irradiation, 90% degradation of LVX was attained in 240 min at optimum conditions (pH–7, catalyst dose–0.25 g/L, and LVX concentration–10 mg/L). The improved photocatalytic ability of composite in contrast to MOF and ZnO could be usually ascribed to the interface created between them, assisting the charge transfer. Additionally, the current system exhibited good recyclability over five runs. Further, to realize the application of NH2-MIL-125(Ti)/ZnO-(II) as a sensor, the material was exposed to the solution of Cu(II) ions and significant quenching was observed demonstrating high selectivity of the current system. Moreover, the detection limit in the linear range of 0–25 μM was calculated to be 1.135 μM which indicated a good sensitivity of the prepared material towards Cu(II) ions, sufficiently low to detect micromolar concentrations of Cu(II). All in all, this study provided a simple and propitious approach for fabricating solar light active photocatalysts for the degradation of organic pollutants and their dual role as fluorescent (FL) sensor towards the determination of Cu(II) ions from aqueous phase.

One‐pot synthesis of copper nanocluster/Tb‐MOF composites for the ratiometric fluorescence detection of Cu2+

The increasing degradation of ecosystems due to heavy metal residues has led to environment and food contamination, prompting the development of convenient platforms for monitoring heavy metals. Here, a new dual-emission fluorescent sensor CuNCs@Tb@UiO-66-(COOH)2 for the detection of copper ions (Cu2+ ) has been synthesized using one-pot encapsulation of Tb(III) and glutathione-stabilized copper nanoclusters (CuNCs) into metal-organic frameworks (MOFs) UiO-66-(COOH)2 . In this ratiometric sensor, the fluorescence intensity of Tb3+ decreased significantly upon the addition of Cu2+ , whereas that of CuNCs showed good stability, together with an apparent colour change. Therefore, ratiometric fluorescence detection of Cu2+ can be accomplished by measuring the ratio of the fluorescence intensity at the 450 nm (F450 ) wavelength of CuNCs to the 548 nm (F548 ) emission of Tb3+ in the fluorescence spectra of the CuNCs@Tb@UiO-66-(COOH)2 suspension. Moreover, the obtained fluorescent probe showed good results in the detection of actual samples. This work can provide the basis of method for the exploration of ratiometric fluorescence and visual sensors of trace pollutants analysis in complicated samples.

A New Spiropyran Hydrazone as an Unusual Colorimetric Sensor for Detection of Cu2+ and Cr3+ Based on Aggregation‐Induced Enhancement Effects in Aqueous Solvent Mixtures

AbstractThough many improvements have been made on fluorescence probes for respective detection of Cu2+ and Cr3+, multiply detect of the ions by a simple colorimetric way in high water content solution sensors remains scarce. In this work, a novel spiropyran hydrazone, [(E)‐(2‐hydroxy‐1‐naphthyl)methylidene][(E)‐[1′,3′,3′‐trimethyl‐6‐(2‐methylprop −2‐yl)‐1′,3′‐dihydrospiro[chromene‐2,2′‐indole]‐8‐yl]methylidene]hydrazine (NA‐SP), which shows aggregation‐induced enhancement effects (AIEE) phenomena in EtOH (ethanol)/H2O and THF (tetrahydrofuran)/H2O media, has been developed. It can detect Cu2+ colorimetrically having a sensitivity of 105 nM in EtOH/H2O (40/60, v/v) with an unusual specific tandem‐response to Cr3+ at a detection limit of 151 nM in addition with a wide pH range of 4–10. Mechanism investigations by HRMS, 1H NMR and UV‐Vis spectroscopy have verified that the response to Cr3+ is based on the cooperative effect between NA‐SP and Cu2+, instead of the replacement of Cu2+ by Cr3+. Moreover, NA‐SP shows a robust AIEE‐caused recognition for Cu2+ in THF/H2O (20/80, v/v) with a detection limit of 16.5 nM. Real water tests indicate that the probe has potential detection application for Cu2+ in environmental situations. This contribution presents a new spiropyran sensor for the detection of Cu2+ and Cr3+ in aqueous solutions through an uncommonly colorimetric way.

Azophenyl appended Schiff base probe for colorimetric detection of Cu2+ in semi‐aqueous medium and live cell imaging

AbstractA phenylazo appended ortho‐vanillin Schiff base scaffold (HAZ) has been used for selective colorimetric sensing of Cu2+ in semi‐aqueous medium (methanol–water, 1:1, v/v) in the presence of 16 cations and 20 anions, and the limit of detection is 1.8 × 10−7 M. The structures of HAZ and Cu (II) complex, [Cu(AZ)2], have been characterised by spectroscopic data (UV–Vis, Fourier transform infrared and electron paramagnetic resonance) and established by the single crystal X‐ray diffraction measurement. The Job's plot from the absorption studies has also confirmed the 1:2 stoichiometry of Cu2+:HAZ. The absorption spectrum of [Cu (AZ)2] has returned to the spectrum of HAZ on the addition of Na2EDTA solution which is again recovered upon the addition of Cu2+ solution. Discrete Fourier transform computations were carried out using the coordinates of the X‐ray structures of the compounds, and the molecular functions were used to correlate the solution spectroscopic properties. In addition to this, the probe is treated on MDA‐MB 231 breast cancer cells to check the cytotoxicity. The probe is used for the detection of trace quantity of Cu2+ in the cancer cell.

Highly Selective Colorimetric Detection of Cu2+ Using EDTA-Complexed Chlorophyll-Copper/ZnO Nanorods with Cavities Specific to Cu2+ as a Light-Activated Nanozyme.

In this study, chlorophyll-copper (ChlCu)-modified ZnO nanorods (ChlCu/ZnO) were prepared, and then sodium ethylenediamine tetraacetate (EDTA) was used to remove part of Cu2+ in ChlCu, leaving cavities with specific adsorption activity for Cu2+ in E-ChlCu/ZnO. Appropriate EDTA treatment improved the photoactivity of ChlCu/ZnO and the adsorption selectivity to Cu2+. However, excessive EDTA treatment might lead to the collapse of the ChlCu structure, resulting in a decrease in photoactivity. The E-ChlCu/ZnO sample with 8 h of ChlCu treatment and 2 h of EDTA treatment showed optimal photoactivity. The as-prepared E-ChlCu/ZnO exhibited activity as a light-activated nanozyme, which could oxidize 3,3',5,5'-tetramethylbenzidine (TMB) to blue under illumination, but when Cu2+ was present in the solution, this colorimetric reaction was inhibited; therefore, E-ChlCu/ZnO could be used for colorimetric detection of Cu2+. Because of the existence of specific cavities, E-ChlCu/ZnO showed excellent detection selectivity, a wide linear detection range (0-1 and 1-15 μM), and a low detection limit (0.024 μM) in the colorimetric detection of Cu2+.