Copper Ion Concentration Research Articles

SEDIMENT MICROBIAL FUEL CELL BASED BIOSENSOR FOR REAL TIME DETECTION OF CU2+ IN INDUSTRIAL WASTEWATERS – OPERATION AND EFFECTIVENESS

Sediment microbial fuel cells (SMFCs) are bio-electrochemical systems in which the anode is placed in the anaerobic sediment and the cathode is immersed in the surface layer of water. Natural exoelectrogenic bacteria decompose organic compounds in sediment, producing electrons and protons. The electrons reach the cathode through an external electrical circuit, while the protons pass through the soil layer, which acts as a kind of membrane. Oxygen is in many cases the preferred electron acceptor due to its presence in the cathode region and its high potential. Heavy metal ions and other compounds can also be reduced on the cathode, which will increase the energy generated. Based on the above characteristics, SMFCs would be suitable for application as biosensors for monitoring water pollution with heavy metals. In the present study, the possibility of application of SMFCs as biosensors for water pollution with copper has been studied. A high correlation was found between the concentration of copper ions in the range 0,1 – 100 mg/L and the voltage generated by SMFC. The constructed SMFC based biosensor showed wider detection limits for copper compared to other authors' studies as the coefficient of determination reached 0,9911. Native exoelectrogenic bacteria were represented mainly by Geobacter, Clostridium, Anaeromixobacter and Bacillus.

Degradation of hydroxyoxime CP-150 in the presence of nitrate and permanganate ions causing detrimental effect on copper extraction

Hydroxyoxime is the most widely used extractant in copper hydrometallurgy. However, due to the unstable structure of hydroxyoxime and the complex and harsh actual operating environment of the copper extraction system, the failure of hydroxyoxime in the copper extraction process due to degradation is of great concern. Currently, most studies mainly focus on verifying the influence of various potential factors on the degradation of hydroxyoxime extractants without considering the operation of the whole system, resulting in its failure problem not being effectively solved. In this paper, the operation of the extraction system was systematically analyzed with the issue of degradation failure of hydroxyoxime extractant in copper extraction and recovery process in the comprehensive recovery of gallium‑germanium copper in Shenzhen Zhongjin Lingnan Nonfemet Co., Ltd. Combining the effects of (i) acidity, (ii) copper ion concentration, (iii) NO3− and (iv) MnO4−, the effect of NO3− on extractant degradation was found to be more prominent, and the nitrification degradation (ND) rate was greatly affected by concentration and temperature. The MnO4− ion is a strong oxidant at high acidity. Its role on oxidation degradation (OD) of hydroxyoxime extractants was limited during the actual operation, overturning the common perception that strong oxidizing MnO4− is the leading cause of OD of hydroxyoxime extractants. Controlling the operating temperature of the extraction process is essential to prevent extractant degradation. In addition, GC–MS and FITR analysis of complex degradation products further validated the hydroxyoxime ND mechanism, which is of great practical significance for controlling the degradation of hydroxyoxime extractant in the copper extraction and recovery process from the origin.

Modified Agricultural Waste for Copper Ions Adsorption

The present work represents potential bio-sorbents: Tilia cordata (little leaf linden) and Foeniculum vulgare (fennel). The copper removal was operated in batch procedure. Adsorbent mass, copper ion concentration, pH, time, and temperature considerations were inspected. The highly beneficial provisions for copper adsorption are 10 mg /L as preliminary concentration, 0.2 g as Tilia cordata and Foeniculum vulgare mass and pH 5.5 and 5.23 for Tilia cordata and Foeniculum vulgare. Adsorption statistics follow the Langmuir isotherm with qmax of 29.35 mg/g for Tilia cordata and 32.98 mg/g for Foeniculum vulgare. The removal procedure kinetics was provided perfectly via second-order equations. It was revealed that the copper ion adsorption procedure on mutual bio-sorbents is a spontaneous procedure, and is endothermal for Tilia cordata and Foeniculum vulgare. Characterization of Tilia cordata (little leaf linden) and Foeniculum (vulgare fennel) were inspected with a scanning electron microscope (SEM), Vis-IR Spectroscopy, GC-mass and milling cutter. A distinctive development in the adsorbent surface was exhibited through scanning electron microscope. The removal efficiency reached to 93.34 & 95.4 for Tilia (Tilia cordata) and Fennel (Foeniculum vulgare) respectively at 0.5 M bio-sorbent which indicated that Tilia (Tilia cordata) and Fennel (Foeniculum vulgare) has good renderability and stability.

Integrating bi-pH operation to enhance Ni2+ removal and recovery in fluidized-bed non-seeded granulation process

Anthropogenic activities and industrial processes generate large amounts of nickel in effluent, posing a threat to public and ecological health. Several processes have been developed to remove nickel and adhere to environmental limits. The fluidized-bed non-seeded granulation process has proven effective in removing and recovering metals including nickel. In this study, nickel was precipitated using phosphate while investigating bi-pH operation. The study compared single-pH and bi-pH and found that bi-pH was better. The effects of molar ratio ([Ni2+]:[PO43-]), initial nickel concentration, copper ion concentrations, and other co-existing chemical compounds were then investigated under bi-pH operation. The optimal conditions were observed at bi-pH 7.5 and 9.0, molar ratio of 1:1.3, and 300 mg/L initial nickel concentration. The results showed that bi-pH improved the granulation process by generating heterogeneous granulation through observed bi-layers. The effects of molar ratio and initial nickel concentrations were attributed to changes in the predominant saturation condition, dictating primary and secondary nucleation. Co-existing compounds had no significant effect on total nickel removal but reduced granulation efficiency due to nickel complexation, ionic competition, and precipitate dissolution.

Study of the Antibacterial Capacity of a Biomaterial of Zeolites Saturated with Copper Ions (Cu2+) and Supported with Copper Oxide (CuO) Nanoparticles.

In this work, copper (II) ions were saturated and copper oxide nanoparticles (CuO NPs) were supported in natural zeolite from Chile; this was achieved by making the adsorbent material come into contact with a copper ion precursor solution and using mechanical agitation, respectively. The kinetic and physicochemical process of the adsorption of copper ions in the zeolite was studied, as well as the effect of the addition of CuO NPs on the antibacterial properties. The results showed that the saturation of copper (II) ions in the zeolite is an efficient process, obtaining a 27 g L-1 concentration of copper ions in a time of 30 min. The TEM images showed that a good dispersion of the CuO NPs was obtained via mechanical stirring. The material effectively inhibited the growth of Gram-negative and Gram-positive bacteria that have shown resistance to methicillin and carbapenem. Furthermore, the zeolite saturated with copper at the same concentration had a better bactericidal effect than the zeolite supported with CuO NPs. The results suggested that the ease of processing and low cost of copper (II) ion-saturated zeolitic material could potentially be used for dental biomedical applications, either directly or as a bactericidal additive for 3D printing filaments.

A reversible and ratiometric fluorescent probe based on rhodol derivative with an ESIPT unit for monitoring copper ion content and in situ evaluation of related drugs in cells

The amount of copper ions in the environment has an immediate effect on ecology and food safety, Menkes syndrome and Wilson's disease cause accumulation and deficiency of copper ions in the body, respectively, and neurodegenerative diseases are also closely related to copper ion levels. However, the current copper ion detection technology has a high cost, complex operation, and other disadvantages. In this study, a ratiometric fluorescent probe (RB-DH) was rationally constructed to detect copper ions by coupling benzothiazole to rhodol derivatives. It can be used to determine copper ion concentrations in water samples, agricultural products, cells, and zebrafish. Importantly, due to the reversible response of RB-DH to copper ions, the fluctuation of intracellular copper ion content during the release of copper ion-related drugs (Copper gluconate and D-penicillamine) was successfully monitored with RB-DH for the first time. This study demonstrates RB-DH’s potential application in the evaluation of related drug release effects and serves as a guide for the establishment of portable detection techniques for other important substances.

Cu-doped In2S3 hierarchical structures for photocatalytic organic dye degradation under visible light irradiation

In2S3 materials doped with different concentrations of copper ions (Cu-In2S3) were designed and synthesized, which successfully improves the response to visible light, separation of carriers, and adsorption for rhodamine B of In2S3. Cu-doping improves the photocatalytic activity of In2S3 for dye removal. In2S3 doped with 0.3% Cu2+ exhibits the highest photocatalytic activity for the degradation of rhodamine B. In addition, it shows high photocatalytic stability. The photocatalytic active species capture experiments show that the superoxide radical was the main active substance for the photocatalytic degradation of rhodamine B over 0.3% Cu-In2S3. This study provides a valuable reference for the construction of In2S3-based photocatalytic materials.

Effects of dietary melatonin on growth performance, antioxidant capacity, and nonspecific immunity in crayfish, Cherax destructor.

Melatonin (MT) is an indole hormone widely found in plants and animals. Many studies have shown that MT promotes the growth and immunity of mammals, fish, and crabs. However, the effect on commercial crayfish has not been demonstrated. The purpose of this study was to evaluate the effects of dietary MT on growth performance and innate immunity of Cherax destructor from three aspects of individual level, biochemical level, and molecular level after 8 weeks of culture. In this study, we found that MT supplementation increased weight gain rate, specific growth rate, and digestive enzyme activity in C. destructor compared to the control group. Dietary MT not only promoted the activity of T-AOC, SOD, and GR, increased the content of GSH, and decreased the content of MDA in the hepatopancreas, but also increased the content of hemocyanin and copper ions and AKP activity in hemolymph. Gene expression results showed that MT supplementation at appropriate doses increased the expression of cell cycle-regulated genes (CDK, CKI, IGF, and HGF) and non-specific immune genes (TRXR, HSP60, and HSP70). In conclusion, our study showed that adding MT to the diet improved growth performance, enhanced the antioxidant capacity of hepatopancreas, and immune parameters of hemolymph in C. destructor. In addition, our results showed that the optimal dietary supplementation dose of MT in C. destructor is 75-81mg/kg.

INFLUENCE OF COPPER IONS ON GROWTH OF SMALL VASILISTNIK CELL CULTURE (THALICTRUM MINUS L.)

Berberin compound with a wide range of biological activity, synthesized in the culture of cells of the medicinal plant Thalictrum minus. The influence of the abiotic elisitor (Cu2 +) on the growth of the Thalictrum minus cell culture and the biosynthesis of protoberberin alkaloids in it at different stages of the growth cycle was investigated. The rapid reaction (after 2 hours) and prolonged (at the end of the growth cycle) were evaluated. The greatest effect of increasing protoberberin alkaloids was observed after exposure to (Cu2 +) 20, 25 mg/L on day 0 after 2 hours, 49 and 114% above control, respectively, while maintaining growth at the control level. By the end of the growth cycle, cell mass and protoberberin alkaloids decreased by 67-70 and 27-53%, respectively (toxic effect). At 5 mg/L (Cu2 +), the reaction was the opposite.After 2 hours, 48% growth stimulation and 48% reduction in protoberberin alkaloids were observed with respect to control. By the end of the growth cycle, an excess of 50% was maintained, and the content of protoberberin alkaloids increased by 60% relative to control. If treatment with Cu2 + was carried out in the middle of the growth cycle, at a concentration of 20, 25 mg/L, both at the rapid reaction (after 2 hours) and at the end of the growth cycle, there was a decrease in growth by 65-71% and the content of protoberberin alkaloids by 52-70%. At 5 mg/l of copper ions, an excess of growth of 50-54% was maintained, the alkaloid content remained at the control level. The reaction at 10 mg/L of Cu2 + ions was intermediate. Studies have shown the promise of using low concentrations of copper ions for Thalictrum minus cell culture. The content of protoberberin alkaloids increased against the background of stimulation of cell culture growth at the end of the growth cycle.

Dual-mode optical chemodosimeter for detecting copper ions in the environment, food, and living organisms with smartphone

Techniques for the detection and quantification of active ingredients in plants and foods are of global interest in the field of smart agriculture. The amount of copper ions (Cu2+) in the environment is closely related to water quality, food safety, and biological health. However, the drawbacks of the current copper ions detection techniques include difficult operation and inconvenient field analysis. Due to the reliable analytical parameters, dual-mode optical analysis has become increasingly interesting and popular. Therefore, in this study, a dual-mode optical copper ions detection method was constructed based on a fluorescent chemodosimeter RH-HP. The reaction-based recognition process improves its specificity for copper ion recognition and can be utilized to determine the concentration of copper ions in water samples, agricultural products, cells, and zebrafish. It is worth noting that the analysis and photo function of the smartphone is used to establish the relationship between the change of color RGB values and copper ions concentration. This work offers an economical, portable tool for the in-situ detection of copper ions, demonstrating its potential application for monitoring plant growth processes in future smart agriculture, and provides a reference for the establishment of in-situ portable detection methods for other important substances.

Cuproptosis-related genes signature and validation of differential expression and the potential targeting drugs in temporal lobe epilepsy.

Introduction: Temporal lobe epilepsy (TLE) is the most common subtype of epilepsy in adults and is characterized by neuronal loss, gliosis, and sprouting mossy fibers in the hippocampus. But the mechanism underlying neuronal loss has not been fully elucidated. A new programmed cell death, cuproptosis, has recently been discovered; however, its role in TLE is not clear. Methods: We first investigated the copper ion concentration in the hippocampus tissue. Then, using the Sample dataset and E-MTAB-3123 dataset, we analyzed the features of 12 cuproptosis-related genes in TLEs and controls using the bioinformatics tools. Then, the expression of the key cuproptosis genes were confirmed using real-time PCR and immunohistochemical staining (IHC). Finally, the Enrichr database was used to screen the small molecules and drugs targeting key cuproptosis genes in TLE. Results: The Sample dataset displayed four differentially expressed cuproptosis-related genes (DECRGs; LIPT1, GLS, PDHA1, and CDKN2A) while the E-MTAB-3123 dataset revealed seven DECRGs (LIPT1, DLD, FDX1, GLS, PDHB, PDHA1, and DLAT). Remarkably, only LIPT1 was uniformly upregulated in both datasets. Additionally, these DECRGs are implicated in the TCA cycle and pyruvate metabolism-both crucial for cell cuproptosis-as well as various immune cell infiltrations, especially macrophages and T cells, in the TLE hippocampus. Interestingly, DECRGs were linked to most infiltrating immune cells during TLE's acute phase, but this association considerably weakened in the latent phase. In the chronic phase, DECRGs were connected with several T-cell subclasses. Moreover, LIPT1, FDX1, DLD, and PDHB were related to TLE identification. PCR and IHC further confirmed LIPT1 and FDX1's upregulation in TLE compared to controls. Finally, using the Enrichr database, we found that chlorzoxazone and piperlongumine inhibited cell cuproptosis by targeting LIPT1, FDX1, DLD, and PDHB. Conclusion: Our findings suggest that cuproptosis is directly related to TLE. The signature of cuproptosis-related genes presents new clues for exploring the roles of neuronal death in TLE. Furthermore, LIPT1 and FDX1 appear as potential targets of neuronal cuproptosis for controlling TLE's seizures and progression.

STUDY OF SORBSION PROPERTIES OF COPPER (II) ION WITH CHITOSAN BASED SORBENT

Over the past few decades, a significant increase in the use of heavy metals has led to an increase in the amount of metals in the aquatic environment. For living organisms, among heavy metals, copper (II) is one of the toxic metals and one of the most common environmental pollutants. Excessive concentrations of Cu2+ ions can cause various diseases and intoxications in humans. In this regard, the use of absorbents for the sorption of metals is both an economically and technologically efficient method. Quaternized natural polymer chitosan was used as a sorbent to study the sorption properties of copper (II) ion. During the research, the optimal conditions of the sorption process was determined, pH effect of the environment, initial concentration of the metal on the sorption process were studied. The sorption capacity of the synthesized sorbent towards the Cu (II) ion was studied and it was determined that the maximum sorption capacity equal to 255 mg/g was at pH=4. Moreover the influence of copper (II) ion concentration on the sorption process was studied. It was found that the sorption capacity and sorption degree of the sorbent increase with an increase in the concentration of the Cu2+ ion in the solution. It was determined that the maximum sorption capacity was 406 mg /g, which corresponds to the concentration of copper (II) ion, equal to 10∙10-2 mol/L. The results show that quaternized chitosan-based sorbent can be successfully used for the sorption of Cu (II) ion

A Low-Cost Colorimetric Assay for the Analytical Determination of Copper Ions with Consumer Electronic Imaging Devices in Natural Water Samples.

This study reports a new approach for the determination of copper ions in water samples that exploits the complexation reaction with diethyldithiocarbamate (DDTC) and uses widely available imaging devices (i.e., flatbed scanners or smartphones) as detectors. Specifically, the proposed approach is based on the ability of DDTC to bind to copper ions and form a stable Cu-DDTC complex with a distinctive yellow color detected with the camera of a smartphone in a 96-well plate. The color intensity of the formed complex is linearly proportional to the concentration of copper ions, resulting in its accurate colorimetric determination. The proposed analytical procedure for the determination of Cu2+ was easy to perform, rapid, and applicable with inexpensive and commercially available materials and reagents. Many parameters related to such an analytical determination were optimized, and a study of interfering ions present in the water samples was also carried out. Additionally, even low copper levels could be noticed by the naked eye. The assay performed was successfully applied to the determination of Cu2+ in river, tap, and bottled water samples with detection limits as low as 1.4 µM, good recoveries (89.0-109.6%), adequate reproducibility (0.6-6.1%), and high selectivity over other ions present in the water samples.

An improved hyperspectral sensing approach for the rapid determination of copper ion concentrations in water environment using short-wavelength infrared spectroscopy

Copper ion is one of the hazardous pollutants often present in industrial wastewater or acid mine drainage that is regarded as a primary environmental challenge. Hyperspectral remote sensing has a long tradition in water quality monitoring. However, its application in heavy metal detection is relatively similar, and the detection is highly influenced by water turbidity or total suspended matter (TSM), requiring research efforts to improve accuracy and generalize the applicability of this technique. In this study, the use of simple filtration (pore size of 0.7 μm) for sample pretreatment to improve hyperspectral remote sensing of copper ion concentrations (Cu, 100–1000 mg/L) in water samples is proposed. A wide variety of water samples, including as-prepared and field (fish pond and river water) samples, were investigated to validate the developed method. Spectral data containing sensitive bands characterized in the range of 900–1100 nm were first preprocessed with logarithm transformation, followed by quantitative prediction model development using stepwise multivariate linear regression (SMLR) with the most sensitive wavebands at around 900 nm and 1080 nm. Satisfactory prediction performance for Cu ions was found for turbid water samples (TSM greater than approximately 200 mg/L) after simple filtration pretreatment, suggesting that pretreatment removed suspended solids in the mixtures and enhanced the spectral features of Cu ions in the model. Moreover, good agreement between the laboratory results and the field samples (adjusted R2 > 0.95 and NRMSE <0.15) highlights the suitability of the developed model and filtration pretreatment for obtaining relevant information for the rapid determination of Cu ion concentrations in complex water samples.

Bio-Electrochemical Recovery of Copper from Dilute Acidic Solutions as a Function of External Resistance, Copper and Iron Concentrations

Bioelectrochemical systems provide a promising tool for the copper recovery from the heap leaching solutions which usually contain low copper and high iron concentrations. In this study, the role of copper and ferrous ion concentrations, and external resistance in the removal of synthetic sulfuric acid solutions by a lab-scale Microbial Fuel Cell (MFC) was investigated and good results were obtained in the removal of copper.

Effects of Coupled-/soluble-Copper, Generating from Copper-doped Titanium Dioxide Nanotubes on Cell Response.

Endothelialization in vitro is a very common method for surface modification of cardiovascular materials. However, mature endothelial cells are not suitable because of the difficulty in obtaining and immunogenicity. In this patent work, we determined the appropriate amount of copper by constructing a copper- loaded titanium dioxide nanotube array that can catalyze the release of nitric oxide, compared the effects of coupled-/soluble-copper on stem cells, and then induced stem cells to differentiate into endothelial cells. The results showed that it had a strong promotion effect on the differentiation of stem cells into endothelial cells, which might be used for endothelialization in vitro. SEM and EDS results prove that a high content of copper ions are indeed doped onto the surface of nanotubes with small amounts of Cu release. The release of NO confirms that the release of several samples within a period of time is within the physiological concentration.

Surface Oxidation and Wetting Synergistic Effect of Liquid Metals.

Various functions of liquid metals are closely related to their surface performances, among which oxidation and wetting are the two most important surface processes. The two processes of liquid metals are inseparable in most practical applications; however, the coupling of oxidation and wetting of liquid metals has received little attention. Here, we demonstrate the synergistic effect of oxidation and wetting of liquid metals through establishing a liquid system containing the copper ion acid solution. By modulating the concentrations of copper ions and hydrogen ions, three different modes of the liquid metal surface are presented, where the oxidation process and the wetting process are in a competitive relationship. Whichever of the two processes is dominant can determine the stability of copper particles produced on the surface of liquid metals, that is, affect whether the "phagocytosis" process can occur. It is revealed that the magnitude of current density on the surface of liquid metals, caused by galvanic corrosion behavior between liquid metals and copper particles, is the key factor influencing the dominance of different surface processes of liquid metals. Utilizing the synergistic effect, we prepare a liquid metal film with adjustable reflectivity, in which surface states can be changed repeatedly between the bright state and the darken state by simple solution immersion. The liquid metal film with different surface states can show obvious difference in optical performance, which has application potential in color camouflage. Understanding the surface synergistic effect will facilitate further exploration of the abundant exotic liquid metal interface phenomena.

Prediction of Deposition Rate in Meniscus‐Confined Electrodeposition Based on Parameter Optimization Algorithm

Meniscus‐confined electrodeposition (MCED) is a potential approach to fabricate 3D metallic microstructures and can be used in microelectromechanical systems, optoelectronics, and flexible electrical interconnections. However, deposition efficiency and the quality of the microstructures obtained by this method on optimal parameters are identified by a large number of comparative experiments, resulting in high cost and inefficient practices. For this reason, herein, the fabrication process of metal microstructures by MCED simulation and optimizes parameters affecting deposition quality and rate is investigated. First, the finite‐element method is used to simulate the voltage and copper ion concentration identifies the target range. Then, the electrodeposition rate 1 × 10−7 m s−1 is set as the target value. The best applicable values of 0.29 V and 0.46 m are obtained after optimizing the voltage and copper ion concentration that affects the quality of deposited microstructures and rate of MCED based on the genetic algorithm (GA), cuckoo search (CS) algorithm, and support vector regression (SVR) algorithm. Finally, simulations and experiments are carried out according to the optimized parameters values. The results show that the maximum error of deposition rate is 7.9%. This study pioneers a new approach to achieving efficient and high‐quality deposition by MCED.

Isotermal Adsorpsi Ion Tembaga (II) Menggunakan Arang Tongkol Jagung (Zea mays L.) Teraktivasi Kalium Permanganat

Corn cobs which generally only become waste can be processed into activated carbon and used for the absorption of heavy metals, such as copper(II) ions. This study aims to determine the morphology of corn cobs charcoal after activation, determine the isothermal adsorption model of copper (II) metal ions on corncob-activated carbon, and then determine the adsorption capacity of copper (II) metal ions on corncob-activated carbon. The morphology of the corncob-activated charcoal obtained was analyzed using Scanning Electron Microscopy (SEM). Isothermal adsorption of copper (II) ions was carried out with various concentrations of copper (II) ions of 5, 10, 20, 50, and 100 ppm. The results of the analysis using SEM showed that the surface shape of the corncob-activated charcoal is regular and has pores with a pore diameter obtained in the range between 1.08-1.26 m and 1.38-1.59 m. The mechanism of adsorption of copper (II) ions by corncob-activated charcoal using KMnO4, following the Freundlich isothermal model with a value of R2 0.9993 with an adsorption capacity of 51 x 10-4 mmol/L. The utilization of activated carbon from corn cobs that are activated by potassium permanganate is very effective for adsorbing copper metal ion pollutants through an adsorption mechanism on the surface of activated carbon.

A Novel Cu2+ Quantitative Detection Nucleic Acid Biosensors Based on DNAzyme and “Blocker” Beacon

In this paper, a "turn-off" biosensor for detecting copper (II) ions based on Cu2+-dependent DNAzyme and a "blocker" beacon were developed. Upon the copper ion being added, the Cu2+-dependent DNAzyme substrate strand was irreversibly cleaved, thereby blocking the occurrence of the ligation reaction and PCR, which inhibited the G-rich sequence from forming the G-quadruplex structure, efficiently reducing the detection signal. This method had the characteristics of strong specificity and high sensitivity compared with the existing method due to the application of ligation-dependent probe signal recognition and amplification procedures. Under the optimized conditions, this method proved to be highly sensitive. The signal decreased as the concentration of copper ions increased, exhibiting a linear calibration from 0.03125 μM to 0.5 μM and a limit of detection of 18.25 nM. Subsequently, the selectivity of this biosensor was verified to be excellent by testing different relevant metal ions. Furthermore, this detection system of copper (II) ions was successfully applied to monitor Cu2+ contained in actual water samples, which demonstrated the feasibility of the biosensor.