Selective Detection Of Metal Ions Research Articles

Synthesis of Yellow-Emitting Fluorescent Aniline-Doped Ellagic Acid via C-N Coupling Reaction and Its Application in the Selective Detection of Metal Ions

Ellagic acid (EA), a natural polyphenol, features a highly organized planar structure with an extensive sp2 carbon-conjugated area, making it favorable for light energy absorption and fluorescent emission. However, this planar structure can easily aggregate through π-π stacking, leading to aggregation-caused quenching of fluorescence. In this research, aniline-doped ellagic acid (EAAn2) was successfully synthesized via a C-N coupling reaction to address this issue. The fluorescence properties of EAAn2 in various organic solvents were thoroughly investigated. Compared to EA, EAAn2 exhibited a red shift in fluorescence emission, primarily revealing yellow fluorescence instead of the green fluorescence of EA. Moreover, the fluorescence intensity and the concentration at which aggregation-caused quenching occurs for EAAn2 were substantially improved due to the two grafted aniline molecules.EAAn2 was utilized as a molecular fluorescent probe in DMSO to detect three kinds of metal ions: alkali and alkaline-earth metal ions, transition metal ions, and post-transition metal ions, using EA as a control. It was found that the combination of EAAn2 with these metal ions exhibited stronger fluorescence intensity than EA and effectively resisted the blue shift in fluorescence emission due to aniline doping. Based on these results, Mg2⁺ ions could be clearly distinguished from other alkali and alkaline-earth metal ions by differences in their fluorescence emission, as could Cr2⁺ ions among transition metals. This research effectively enhances the fluorescence properties of EA through C-N coupling and demonstrates its greater potential in the detection of metal ions, providing fundamental and valuable information for future fluorescent applications.

Development of a Pyrone-Fused Tricyclic Scaffold-based Ratiometric Fluorescent Probe for Al3+ Detection.

Aluminum (Al3+) is environmentally abundant and can harm living organisms in various ways, such as by inhibiting root growth, damaging faunal nervous systems, and promoting tumor cell proliferation. However, the dynamics of Al3+ in living organisms are largely unknown; thus, detecting Al3+ in the environment and organisms is crucial. Fluorescent probes are useful tools for the selective detection of metal ions. In particular, ratiometric fluorescent probes exhibit a detection response at two different maximum fluorescence emission wavelengths; which is advantageous for avoiding the influence of background fluorescence. A novel pyrone-fused tricyclic scaffold-based ratiometric fluorescent probe for detecting Al3+, ethyl 11-imino-1-oxo-3-phenyl-1H,11H-pyrano[4,3-b] quinolizine-5-carboxylate (PQ), was developed in this study. The PQ fluorescence blue shifted from 505 to 457nm upon the addition of Al3+. The blue shift was accompanied by a change in the fluorescence color of the PQ solution from green to blue. Fluorescence titration experiments demonstrated that the fluorescence intensity ratio at the two peaks of interest (457/505nm) increased in a concentration-dependent manner upon the addition of Al3+. Moreover, this study demonstrated that a PQ-soaked paper displays a visible color change under ultraviolet light upon exposure to Al3+. The above results suggest that PQ is an effective ratiometric probe for the detection of Al3+ in the environment. Future studies will be conducted to introduce various substituents and develop fluorescent probes by leveraging the fluorescence property of a pyrone-fused tricyclic scaffolds.

Electronic structure modulation in quinoline derivatives through substituent-mediated effects: Development of AIE fluorescent probes for Fe3+ detection in water samples

Iron (Fe3+) is an essential trace element in biological organisms. Abnormal concentrations of Fe3+ in aquatic possess the potential to disrupt normal physiological and metabolic processes in living organisms. Consequently, the pursuit of developing fluorescent probes for detecting Fe3+ concentrations in water samples is highly significant. The lone electron pair on the nitrogen atom of quinoline demonstrates outstanding coordination capabilities, enabling the selective detection of metal ions through coordination. Nevertheless, the interaction between metal ions and quinoline-based fluorescent probes tends to lead to nanoparticle aggregation, causing aggregation-caused quenching (ACQ) phenomena. This severely restricts the practical application of these probes. To address this challenge, the study utilizes quinoline as the foundational framework and modulates the excited-state electronic structure of quinoline derivatives through substituent effects. This facilitates the transition from ACQ to aggregation-induced emission (AIE). By integrating theoretical calculations, the paper proposes a comprehensive strategy for designing AIE molecules based on quinoline. This contribution provides innovative perspectives on AIE molecule design. Ultimately, the AIE property of the 8-MQB molecule is harnessed to develop a fluorescent probe capable of detecting Fe3+ in water samples. The fluorescence intensity exhibits a robust linear correlation with Fe3+ concentrations within the range of 5.0 μM to 0.3 mM. Moreover, the probe demonstrates exceptional resistance to interference from other metal ions. In conclusion, this research presents a universal strategy for designing AIE molecules and introduces an AIE probe for the rapid detection of Fe3+ concentrations in water samples.

Highly-Selective fluorescent Fe3O4@PPy aptasensor

Label-free nucleic acid fluorescent probes are gaining popularity due to their low cost and ease of application. However, the primary challenges associated with label-free fluorescent probes stem from their tendency to interact with other biomolecules, such as RNA, proteins, and enzymes, which results in low specificity. In this work, we have developed a simple detection platform that utilizes Fe3O4@PPy in combination with a label-free nucleic acid probe, 1,1,2,2-tetrakis[4-(2-bromo-ethoxy)phenyl]ethene (TTAPE) or Malachite Green (MG), for highly selective detection of metal ions, acetamiprid, and thrombin. Fe3O4@PPy not only adsorbs aptamers through electrostatic interactions, π–π bonding, and hydrogen bonding, but also quenches the fluorescence of the TTAPE/MG. Upon the addition of target compounds, the aptasensor separates from Fe3O4@PPy through magnetic separation. Moreover, by changing different aptamers, the aptasensor was applied to detect metal ions, acetamiprid, and thrombin, with the turned-on photoluminescence (PL) emission intensity recorded and showing linearity to the concentrations of targets. The robustness of method was demonstrated by applying it to real samples, which included vegetables (for detecting acetamiprid with LODs of 0.02 and 0.04 ng/L), serum samples (for detecting thrombin with LODs of 5.5 and 4.3 nM), and water samples (for detecting Pb2+ with an LOD of 0.17 nM). Therefore, due to its impressive selectivity and sensitivity, the Fe3O4@PPy aptasensor could be utilized as a universal detection platform for various clinical and environmental applications.

Enhanced luminescent properties of poly(sodium acrylate)-based composite and its selective interaction towards copper ions

This study investigates the luminescent properties and metal ion interactions of europium when combined with a polymer chain of poly (sodium acrylate) (PSA) and a phenanthroline (Phen) molecule, which acts as an efficient antenna. The study of interactions between lanthanide ions and various compounds in different matrices is crucial, providing valuable insights into the molecular environment, and enabling a deeper understanding of processes affecting their luminescence. In this study, we investigated the luminescent properties of the Eu(PSA)Phen complex and its remarkable capacity for selective interaction with Cu2+ ions in an aqueous solution. From this selective interaction, we conducted a series of detailed studies that provided valuable insights into the mechanisms of luminescence suppression, information about the europium chemical environment, and other related aspects. The luminescence of Eu(PSA)Phen is significantly quenched by Cu2+ ions, driven by both static and dynamic mechanisms. The presence of the PSA polymer chain and Phen molecules within the composite exerts a profound influence on energy transfer processes, enabling selective responses to Cu2+ ions, even in the presence of competing cations. Additionally, we observed a preferential interaction of the PSA molecule in the Eu(PSA)Phen composite with Cu2+ ions over the N groups of phenanthroline. These findings underscore the compound potential as a versatile tool in various fields, ranging from material science to biosensing, where rapid and selective metal ion detection is of paramount importance.

Ultra-hybrid sensor based on magnetic and fluorescent biomaterial for the sensitive/selective detection of toxic Ag+ and Hg2+ ions in real samples

The development of high-performance, eco-friendly and magnetic sensors prepared from natural products have recently attracted a lot of attention for the selective detection of metal ions in aqueous environments and the simultaneous detection of metals in the same environment. In this study, a fluorescent and magnetic sensor (MSp-P[5]-EN-B) was prepared by the immobilization of Bodipy and pillar [5]arene on the sporopollenin surface modified by Fe3O4 for the selective detection of Ag+ and Hg2+ ions separately and together in the aqueous solution. The characterization of the fluorescent and magnetic sensor, MSp-P[5]-EN-B, was supported by techniques such as SEM, FT-IR, and XRD. The fluorescence data of MSp-P[5]-EN-B sensor was examined with various concentrations in the range 1–100 μM that in here, an “on-off” fluorescence process for Ag+, and Hg2+ and the detection limits are 0.019 μM and 0.33 μM, respectively. As a result, the designed magnetic MSp-P[5]-EN-B sensor showed strong potential in terms of its accurate, sensitive, and practical application in the separate and simultaneous detection of Ag+ and Hg2+ ions in aqueous media.

Synthesis of rhodamine-helicin fluorescent probe for colorimetric detection of Cu2+ and fluorescent recognition of Fe3+

Fluorescent probes play a crucial role in analytical chemistry and biological imaging, offering selective detection of metal ions. Herein, we present the synthesis and characterization of a novel rhodamine-based fluorescent probe, RbHC (Rhodamine B Helicin), which was obtained through the condensation of rhodamine B hydrazide and helicin in ethanol. The probe demonstrates remarkable selectivity and anti-interference capabilities towards Cu2+ and Fe3+ ions in 80% acetonitrile solution. Spectral titration analysis revealed a linear relationship between the intensity and the concentration of Cu2+/Fe3+. The formation of complex between Cu2+/Fe3+ and RbHC was confirmed to be 1:1, and it was further confirmed by ESI mass spectroscopy and DFT calculations. The coordination with Cu2+/Fe3+ caused the opening of RbHC's spirolactam ring, resulting in distinct color change and red fluorescence emissions. Moreover, RbHC exhibits high stability and water solubility under both acidic and neutral conditions, enabling its application in the imaging of plant tissues. Besides, the absorption intensity of RbHC–Cu2+ increased significantly when exposed to sunshine and 365 nm UV radiation, indicating that it might be used as a potential indicator for measuring outdoor UV intensity.

Excited-state intramolecular proton transfer (ESIPT) active interwoven polycatenated coordination polymer for selective detection of Al3+ and Ag+ ions along with water detection in less polar solvents.

The external stimuli-responsive excited-state intramolecular proton transfer (ESIPT) on/off mechanism is a unique and expedient sensing method that offers easy monitoring through the transition between dual and single-peak emissions. To avail this advantage of ESIPT-based sensing for selective metal ion detection and trace water detection, we have synthesized a 2,5-dihydroxyterephthalate (dht)-based interwoven polycatenated coordination polymer (1). The synthesized compound has been thoroughly characterized using single-crystal and powder X-ray diffraction techniques, along with other physicochemical methods. The synthesized compound exhibits a visual luminescence color change from faint yellow to bright green under UV irradiation in the presence of Al3+ ions. This change is attributed to a blue shift in fluorescence maxima of the keto form of the dht ligand in contact with Al3+ ions. Additionally, the material detects Ag+ ions through an ESIPT-off mechanism. These significant changes in ESIPT - blue shifting for Al3+ and ESIPT-off for Ag+ - start in just 1 mM aqueous solutions of these ions. Significantly, the ESIPT-off for Ag+ is evident even in the presence of other interfering ions. Beyond metal ion detection, this material also offers both qualitative and quantitative sensing of trace amounts of water in various polar organic solvents, such as ethanol (EtOH), tetrahydrofuran (THF), isopropanol (IPA), acetone, and acetonitrile (ACN), through the ESIPT-on/off phenomenon. The activated framework of compound 1 (1') can detect 2%, 4%, 4%, 3%, and 3% water in acetone, ACN, EtOH, IPA, and THF, respectively; through the conversion from a single to dual hump emission alteration. The respective ESIPT peak shift and ESIPT-on/off in the presence of metal ions and water is explained by the interaction between the host coordination polymer and guest analytes.

A new fluorescent vitamin B6-based probe for selective and sensitive detection Ga3+ ions in the environment and living cells

This paper reports on the synthesis and characterization of a new selective fluorescence probe for gallium ions in water and living cells. Hydrazone of pyridoxal 5′-phosphate and thiophene-3-carbohydrazide was demonstrated to be a “turn-on” fluorescence sensor that can selectively detect Ga3+ with a noticeable appearance of cyan fluorescence in aqueous DMSO. The complex stoichiometry of the probe for Ga3+ was determined through various methods and its structure and electronic spectra were optimized by quantum chemical calculations. The probe showed a low detection limit of 34 nM, and is suitable for river water analysis with high ion recovery and exhibits low toxicity on different cell lines. This study provides valuable insights into the design and optimization of fluorescence probes for selective detection of metal ions.

Designing of efficient two-armed colorimetric and fluorescent indole appended organosilicon sensors for the detection of Al(III) ions: Implication as paper-based sensor

Metal ions have significant roles in diagnosis, industry, human health, and the environment. To design and develop new lucid molecular receptors for the selective detection of metal ions is important for environmental and medical applications. In the present work, two-armed indole appended Schiff bases conjoined with 1,2,3-Triazole bis-organosilane and bis-organosilatrane skelton sensors for naked eye colorimetric and fluorescent detection sensors for Al(III) are developed. The introduction of Al(III) in sensor 4 and 5 show red shift in UV–visible spectra, changes in fluorescence spectra and immediate color change from colorless to dark yellow. Furthermore, the pH and time response studies were explored for both sensors 4 & 5. The sensors 4 and 5 exhibited significantly low detection limit (LOD) in nano-molar range 1.41 × 10−9 M and 0.17 × 10−9 M respectively from emission titration. The LOD form absorption titration was found to be 0.6 × 10−7 M for sensor 4 and 0.22 × 10−7 M for sensor 5. In addition, the sensing model is developed as paper based sensor for its practical applicability. The theoretical calculations were performed on Gaussian 03 program by relaxing the structures using Density functional theory.

Two-dimensional bismuth oxyselenide quantum dots as nanosensors for selective metal ion detection over a wide dynamic range: sensing mechanism and selectivity.

Bismuth oxyselenide (Bi2O2Se) nanosheets, a new 2D non-van der Waals nanomaterial having unique semiconducting properties, could be favorable for various sensing applications. In the present report, a top-down chemical approach was adopted to synthesize ultrathin Bi2O2Se quantum dots (QDs) in an appropriate solution. The as-prepared 2D Bi2O2Se QDs with an average size of ∼3 nm, exhibiting strong visible fluorescence, were utilized for heavy-metal ion detection with high selectivity. The QDs show a high optical band gap and a reasonably high fluorescence quantum yield (∼4%) in the green region without any functionalization. A series of heavy metal ions were detected using these QDs. The as-prepared QDs exhibit selective detection of Fe3+ over a wide dynamic range with a high quenching ratio and a low detection limit (<0.5 μM). The mechanism of visible fluorescence and Fe3+ ion-induced quenching was investigated in detail based on a model involving adsorption and charge transfer. Density functional theory (DFT) first principles calculations show that fluorescence quenching occurred selectively due to the efficient trapping of electrons in the bandgap states created by the Fe atoms. This work presents a sustainable and scalable method to synthesize 2D Bi2O2Se QDs for heavy metal ion sensing over a wide dynamic range and these 2D QDs could find potential uses in gas sensors, biosensors and optoelectronics.

Ultrasensitive Detection of Cu(II) and Pb(II) Using a Water-Soluble Perylene Probe.

The selective detection of metal ions in water, using sustainable detection systems, is of crescent importance for monitoring water environments and drinking water safety. One of the key elements of future chemical sciences is the use of sustainable approaches in the design of new materials. In this study, we design and synthesize a low-cost, water-soluble potassium salt of 3,4,9,10-perylene tetracarboxylic acid (PTAS), which shows a selective optical response on the addition of Cu2+ and Pb2+ ions in aqueous solutions. By using a water-soluble chromophore, the interactions with the metal ions are definitely more intimate and efficient, with respect to standard methods employing cosolvents. The detection limits of PTAS for both Cu2+ and Pb2+ are found to be 2 µM by using a simple absorbance mode, and even lower (1 μM) with NMR experiments, indicating that this analyte–probe system is sensitive enough for the detection of copper ions in drinking water and lead ions in waste water. The complexation of PTAS with both ions is supported with NMR studies, which reveal the formation of new species between PTAS and analytes. By combining a low-cost water-soluble chromophore with efficient analyte–probe interactions due to the use of aqueous solutions, the results here obtained provide a basis for designing sustainable sensing systems.

Selective detection of metal ions, sulfites and glutathione with fluorescent pyrazolines: a review

Selective detection of metal ions, sulfites and glutathione with fluorescent pyrazolines: a review

Development of [(2E,6E)-2,6-bis(4-(dimethylamino)benzylidene)cyclohexanone] as fluorescence-on probe for Hg2+ ion detection: Computational aided experimental studies

Selective metal ion detection is highly desired in fluorometric analysis. In the current study a curcumin-based fluorescence-on probe/[(2E,6E)-2,6-bis(4-(dimethylamino) benzylidene) cyclohexanone]/probe was designed for the removal of one of the most toxic heavy metal ion i.e. Hg2+. The structure of the probe was confirmed by FTIR and 1H NMR spectroscopic analysis displaying distinctive peaks. The complex formation between probe and Hg2+ ion was also studied by density functional theory to support the experimental results. Chelation enhanced fluorescence was observed upon interaction with Hg2+ ion. Different parameters like pH, effect of mercury ion concentration, contact time, interference study and effect of probe concentration on the fluorescence enhancement were also investigated. A rapid response was detected for Hg2+ ion with limit of detection and quantification as 2.7 nM and 3 nM respectively with association constant of 1 × 1011 M−2. The probe displayed maximum fluorescence intensity at physiological pH. The results showed that the synthesized probe can be employed as an excellent probe for the detection and quantification of Hg2+ ions in aqueous samples with high selectivity and sensitivity due to its higher binding energy and larger charge transferring ability.

Chain length effect of spiro-ring N-alkylation on photophysical signalling parameters in Fe(III) selective rhodamine probes.

Manifestation of photophysical signalling parameters in rhodamine derivatives exhibiting complexation induced spiro-ring opening is crucial for the realization of selective metal ion detection at trace levels. Substitution of various functional groups, such as alkylation to the core architecture, modulates the physico-chemical properties of such molecular probes. Despite a few studies, relationships between the extent of photophysical signal modulations and the chain lengths of n-alkyl substituents are still elusive. In this investigation, a few molecular probes based on the rhodamine B (1-5) and rhodamine 6G (6-10) platform were synthesized by their derivatization with n-alkyl substituents of varying chain lengths at the amino-donor of their spiro-ring end, which exhibited Fe(III)-selective absorption and fluorescence 'off-on' signal transduction along with colorization of solution. The Fe(III)-selectivity in these probes remained the same despite their structural distinctions through varied n-alkyl chain lengths of the substituents; however, the quantifiable signalling parameters such as spectroscopic enhancement factors, sensitivity, the kinetics of spiro-ring opening and effectiveness of probe-Fe(III) interactions were analyzed. These parameters were also correlated in terms of the influence of different chain lengths of n-alkyl substituents that efficiently contributed to their inter-componential interactive stereo-electronic environment.

A novel turn-on fluorescent probe based on berberine for detecting Hg2+ and ClO− with the different fluorescence signals

Development of a high performance fluorescent sensor from natural berberine for selective detection of metal ions and anions is a great challenge. Herein, a novel turn-on fluorescent probe TB for the detection of both Hg2+ and ClO− has been successfully designed and synthesized from berberine. The probe TB showed good selectivity and sensitivity to Hg2+ and ClO− in CH3OH/PBS (7:3, v/v, pH = 7.4, 10 mM) solution, and it emitted yellow fluorescence upon the addition of Hg2+ and cyan fluorescence upon the addition of ClO−. Moreover, the limits of detection (LOD) for Hg2+ and ClO− were calculated to be 0.409 μM and 0.295 μM based on 3σ/k method, respectively. In addition, the mechanisms of TB for sensing Hg2+ and ClO− were established based on HRMS, Job's plot and 1H NMR titrations. Furthermore, the probe TB displayed many important practical applications, such as water sample analysis, imaging in plant cell and zebrafish bioimaging.

Highly sensitive and selective colorimetric detection of dual metal ions (Hg2+ and Sn2+) in water: an eco-friendly approach.

Application of an alliin-based precursor for the synthesis of silver nanoparticles (Ag NPs) which is an emerging, reliable and rapid sensor of heavy metal ion contaminants in water is reported here. The Ag NPs were characterized by using UV-visible spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy analysis techniques. The Ag NPs simultaneously and selectively detect Hg2+ and Sn2+ ions from aqueous solution. The sensitivity and selectivity of the prepared Ag NPs towards other representative transition-metal ions, alkali metal ions and alkaline earth metal ions were also studied. For more precise evidence, a density functional theory study was carried out to understand the possible mechanism and interaction in the detection of Hg2+ and Sn2+ by Ag NPs. The limits of detection for Hg2+ and Sn2+ ions were found as 15.7 nM and 11.25 nM, respectively. This assay indicates the possible use of garlic extract-synthesized Ag NPs for sensing Hg2+ and Sn2+ in aqueous solution very significantly. So, the simple, green, eco-friendly and easy method to detect the dual metal ions may further lead to a potential sensor of heavy metal ion contaminants in water of industrial importance.

Controllable polymeric pseudo-crown ether fluorescent sensors: responsiveness and selective detection of metal ions

A series of responsive polymeric fluorescent sensors were fabricated by post-grafting pyrene and poly(ethylene glycol) onto the backbone of a pseudo-crown ether containing cyclopolymers, and showed good selective recognition toward metal ions.

Novel integrated sensing system of calixarene and rhodamine molecules for selective colorimetric and fluorometric detection of Hg2+ ions in living cells.

Three novel and facile calixarene derivatives (5, 6 and 7), which were appended with four rhodamine units at the upper rim of calixarene skeleton, were firstly prepared and evaluated for selective detection of metal ions in solution. Receptors (5) and (7) indicated immediate turn on fluorescence output toward Hg2+ ions over other most competitive metal ions with the ultralow detection limits, indicating their high efficiency and reliability. The binding response to Hg2+ ions in solution was also observed through a chromogenic change (from colorless to pale pink). Furthermore, in vitro and bio-imaging studies with MCF-7 or MIA PaCa-2 cell lines were also performed to investigate the use of receptors in biological systems in order to monitor of mercury ions. Results showed that new receptors (5) or (7) were cell permeable and suitable for real-time imaging of Hg2+ in living cells (MCF-7) or (MIA PaCa-2) without any damage to healthy cell lines (HEK 293).

The Performance of Various SWCNT Loading into CuO–PMMA Nanocomposites Towards the Detection of Mn2+ Ions

The well-dispersed CuO doped poly(methyl methacrylate) (CuO–PMMA) nanocomposites (NCs) with a successful loading of SWCNT as carbon nanofillers with different percentages (2%, 5%, and 10%) were fabricated effectively via the ex-situ polymerization technique. XRD, SEM–EDX, SEM-Map, TEM, AFM, Raman, and FTIR were carried out to confirm the formation of CuO–PMMA NCs, as well as the formation of CuO–PMMA–SWCNT NCs on the surface of CuO–PMMA sheet nanocomposite. The morphology of both CuO nanoparticles and SWCNT on the PMMA sheet, as well as agglomeration, concentration, roughness profiles, and size distribution, were considered during the experiments. BET surface area was carried out to determine the effect of various percentages of SWCNT loading on CuO–PMMA NC on the BET surface area. Furthermore, thermogravimetric analysis was conducted to evaluate the thermal behavior. Interestingly, the thermal stability of the NCs was inferred to significantly enhance with a proper amount of SWCNTs. EDX and elemental mapping of Cu, C, and O confirmed the presence of SWCNTs and CuO on the PMMA polymer matrix. In this approach, various loadings of SWCNT were performed into the CuO–PMMA–SWCNT NCs for the selective detection of metal ions using the electrochemical method. It exhibited the best performance in the detection of particular Mn2+ cation to 2% of SWCNT loading into NCs. The Mn2+ cationic sensor analytical response was investigated by CuO–PMMA–SWCNT (2%) NCs with glassy carbon electrode (GCE) coated uniform thin film using conductive nafion (5% nafion) binder. The sensor showed linear electrochemical responses over the concentration range of 0.1 nM to 0.01 mM identified through the calibration curve, which is known as the linear dynamic range. The sensor analytical performance sensitivity (88.16 µA µM−1 cm−2) and detection limit (92.67 ± 4.63 pM) were calculated from the slope of the calibration curve. The proposed Mn2+ ion sensor based on CuO–PMMA–SWCNT (2%) NCs/binder/GCE was found satisfactory in terms of reproducibility, linear dynamic range detection limit, sensitivity, stability, and response time. In real environmental samples, it also showed substantial performances during detection. This methodology can be inferred safely as a unique approach to develop metal ion sensors using inorganic-carbon NCs on GCE.