Kinds Of Metal Ions Research Articles

One-Pot Synthesis of Nanoflower-Like Zn2SnS4 as Nanozymes for Highly Sensitive Electrochemical Detection of H2O2 Released by Living Cells.

The sensitive and reliable nanozyme-based sensor enables the detection of low concentrations of H2O2 in biological microenvironments, it has potential applications as an in-situ monitoring platform for cellular H2O2 release. The uniformly dispersed bimetallic sulfide (Zn2SnS4) nanoflowers were synthesized via a one-pot hydrothermal method and the two kinds of metal ions can serve as morphology and structure directing agents for each other in the synthetic process. The nanoparticles were utilized as nanozyme materials to fabricate a novel electrochemical sensor, and it exhibits a distinct electrochemical response towards H2O2 with excellent stability and detection capability (with a minimum detection limit of 1.79 nM (S/N=3)), the excellent characteristics facilitate the precise detection of low concentrations of H2O2 in biological microenvironments. Use the macrophages differentiated from leukemia THP-1 cells as a representative sensing model, the sensor was successfully utilized for real-time monitoring of the release of H2O2 induced by living cells, which has significant potential applications in clinical diagnosis and cancer treatment.

Metal Ion-Doped Hydroxyapatite-Based Materials for Bone Defect Restoration.

Hydroxyapatite (HA)-based materials are widely used in the bone defect restoration field due to their stable physical properties, good biocompatibility, and bone induction potential. To further improve their performance with extra functions such as antibacterial activity, various kinds of metal ion-doped HA-based materials have been proposed and synthesized. This paper offered a comprehensive review of metal ion-doped HA-based materials for bone defect restoration based on the introduction of the physicochemical characteristics of HA followed by the synthesis methods, properties, and applications of different kinds of metal ion (Ag+, Zn2+, Mg2+, Sr2+, Sm3+, and Ce3+)-doped HA-based materials. In addition, the underlying challenges for bone defect restoration using these materials and potential solutions were discussed.

Fabrication and characterization of magnetic cobalt ferrite intercalated chitosan grafted polyaniline ternary nanocomposites for removing some heavy metals simultaneously

Chitosan grafted polyaniline (Ch-g-PANI) loaded with different concentrations of cobalt ferrite magnetic (CoFM) nanoparticles (2, 5 and 10 wt%) to form (Ch-g-PANI/CoFM) nanocomposites were fabricated. X-ray diffraction (XRD), High-Resolution Transmission Electron Microscope (HRTEM), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray (EDX), Fourier transform inferred (FT-IR), and Vibrating Sample Magnetometer (VSM) were carried out to investigate the structure, morphology, chemical composition, and magnetic properties of Ch-g-PANI and Ch-g-PANI/CoFM) nanocomposites. Adsorption performance of these prepared samples towards heavy metals (Pb2+, Cu2+, Fe3+, Cd2+, Li1+, Co2+, Al3+, Mn2+, Zn2+, Ni2+, Cr2+, and V2+) was investigated. The effects of CoFM NPs concentraion doped in grafted polymer, initial metal concentration, temperature, pH, and contact time on heavy metal removal efficiency were optimized. SEM revealed abundant pores for optimum sample that enhance the heavy metal removal efficiency. Competitive adsorption tests proved that Ch-g-PANI/CoFM5 NPs showed higher efficiency for tested heavy metals. The removal efficacy of optimum sample (Ch-g-PANI/CoFM5) reached maximum values 98, 95.3, 96, 99.2, 97, 99.9, 88, 94.4, 99.8, 93.4, 98.96, 93, and 93.9 % for Pb2+, Cu2+, Fe3+, Cd2+, Li1+, Co2+, Al3+, Mn2+, Zn2+, Ni2+, Cr2+, and V2+, respectively at 90 min(equilibrium time), the element ions concentration of 10 mg/L and pH range of 4–6 depending on the kind of metal ions. Freundlich model is the best isotherm model for the equilibrium data, suggesting the multilayer adsorption on the heterogeneous surface. The kinetic data specified that the pseudo-first-order model fitted the adsorption of heavy metal ions on Ch-g-PANI/CoFM5. Thermodynamic studies elucidated the feasible, spontaneous, random, and endothermic adsorption. From an economic viewpoint, the regeneration study implied that the optimal sample Ch-g-PANI/CoFM5 was efficiently recovered up to four successive cycles.

Preparing the pure lignin peroxidase and exploring the effects of chemicals on the activity

Heterogous expression of lignin peroxidase (LiP) from Phanerochaete chrysosporium was performed in by E. coli prokaryotic expression system, and pure LiP was prepared by washing, refolding, and purification. The enzyme activity was measured by the resveratrol oxidation method. The effects of different chemicals on LiP activity were explored by adding different kinds of metal ions, acids/phenols, and surfactants. The optimal pH and temperature are 4.2 and 40 °C. The single-factor screening experiment showed that adding 1 mM Mn2+, 0.1 mM DL-lactic acid, and 2% PEG-4000 had the best promotion effect on the enzyme activity of recombinant LiP, which was 160.61%, 188.46%, and 247.83%, respectively. Further, the synergistic addition of Mn2+ and PEG-4000 achieved the best enzyme activity promotion effect of 277.51%. In addition, the addition of DL-lactic acid alone could promote LiP activity. However, the co-addition of lactic acid with Mn2+ and PEG-4000 contributed only 247.87%, which indicated that the addition of DL-lactic acid had an inhibitory effect when applied synergistically. For the first time, it was found that PEG-4000 increased LiP enzyme activity obviously and had a synergistic effect with Mn2+, serving as a reference for LiP in studies and applications pertaining to lignin breakdown.

Thiourea-cyanostilbene derivative: An effective fluorescent sensor for Pd2+ in aqueous media

Although some Pd2+ sensors were presented, the in-situ and real-time examination of Pd2+ based on fluorescent sensor is still a challenging task. In this work, a novel thiourea-cyanostilbene derivative (TCS) was designed and synthesized as the effective fluorescent sensor on in-situ and real-time sensing Pd2+ in aqueous media. TCS possessed good AIE fluorescence in THF/H2O solution. The fluorescence was selectively quenched by Pd2+ among all kinds of metallic ions. The sensing mechanism of 1:1 stoichiometry ratio for TCS with Pd2+was confirmed by Job's plot, 1H NMR and MS spectra. The detection limit was as low as 4.32 × 10−8 M. TCS exhibited the good sensing application for Pd2+ in tested paper and simulated samples with low errors. TCS had the excellent fluorescence imaging performance in living cells with the fluorescence imaging response on Pd2+. This research not only reported an effective fluorescence sensor for Pd2+, but also suggested the good application prospect on in-situ and real-time sensing Pd2+ in complicated environment.

Trimetallic metal–organic framework nanosheets as nanozymes for the electrochemical sensing of H2O2

A variety of two-dimensional (2D) metal–organic framework (MOF) nanosheets have been discovered with excellent peroxidase-like activity due to their merits of accessible active sites and large surface area. However, few methods can be used for the large-amount production of 2D MOF nanosheets. Herein, we report a simple room temperature solution phase method for the high-yield synthesis of 2D trimetallic MOF nanosheets with three kinds of metal ions as ligands. The as-synthesized NiCoM (M = Cu, Fe, and Zn) nanosheets showed markedly enhanced electrochemical activity due to the synergistic effect. Among these obtained nanosheets, NiCoFe showed the highest electrocatalytic activity, demonstrating that Fe played a dominant role in determining the activities of nanozymes. As a proof-of-concept application, 2D NiCoFe nanosheets are used as modified materials for the electrochemical detection of H2O2. The results showed that the fabricated sensor can detect hydrogen peroxide (H2O2 ) with a detection range of 5.0 μM − 15 mM, a detection limit of 2.1 μM, excellent selectivity and stability. Moreover, the fabricated NiCoFe nanosheet-based electrochemical sensor can be used for the detection of H2O2 in serum samples. Our work provides a scalable method for the large-scale synthesis of 2D trimetallic MOF nanosheets as enhanced nanozymes for various applications.

First principles calculation study of single transition metal atom grafted Au25 as efficient electrocatalysts for OER and ORR

The method of grafting metal atoms by ligands can construct 'grafted single-atom catalysts' with good catalytic activity without destroying the cluster structure. In this study, the catalytic performance of Fe2+, Co2+ and Ni2+ grafted Au25(SR)18 cluster through l-cysteine ligand as bridging ligand (denoted as Au25-nCys-M, where n is the number of grafted Cys-ligand) in OER and ORR was investigated by density functional theory (DFT) simulations. A volcanic diagram between the overpotential of OER and ORR and the adsorption free energy of intermediates on Au25–nCys-M was determined, which showed that the adsorption strength of oxygenated intermediates can be adjusted by the grafting method and the number of bridging ligands, thus affecting the catalytic performance. Among three kinds of metal ions, the grafted Ni2+single atom catalysts showed excellent bi-functional OER and ORR activities. In particular, the Au25–1Cys-Ni2+ (n = 1) had the lowest overpotentials of 0.48 and 0.27 V for OER and ORR. Through in-depth analysis, we found that the spin magnetic moments of metal cations can be used as the descriptor of the catalytic performance of the grafted single atom catalyst. The excellent catalytic performance of Au25–nCys-Ni2+was originated from the smaller spin magnetic moment of Ni2+. These findings provided new idea for the preparation of nanocomposites with excellent OER and ORR catalytic performance.

Study on the Influence of Metal Ions on the Dispersion of Fine Calcium Gangue Minerals.

In this study, the calcium gangue material calcite (-10 μm) was used to investigate the effects of different kinds of metal ions and dosages on the dispersion behavior of calcite. The test results showed that the dispersion behavior of calcite was poor under strongly alkaline conditions without the addition of metal ions, and the reason for that was calcite dissolved ions. The degree of influence of different metal ions on calcite dispersion behavior was Fe3+ > Mg2+ > Na+. The three metal ion dosage tests showed that the dispersion behavior of calcite became poorer with the increase of metal ion dosage. This mainly showed that with the increase of Na+ dosage, the trend of the dispersion behavior of calcite was not obvious, but with the increase of Fe3+ and Mg2+ dosage, the trend of calcite dispersion behavior changed more. The dispersion behavior of calcite was devastated by 5 × 10-4 mol/L Fe3+ at pH = 4-12. The different mechanisms of the three metal ions were identified by zeta potential, solution chemistry, and XPS analysis. Na+ only changed the zeta potential value of the calcite surface, which acted as a compressed electric double layer. However, the formation of metal hydroxide species or metal hydroxide surface precipitation due to the adsorption of Fe3+ and Mg2+ on the mineral surface resulted in the change of the dispersion behavior of calcite.

Synthesis and photophysical properties of vice-like 1,8-naphthalimide fluorescent sensor for sensitive detection of Mn2+ and Zn2+

Building fluorescence sensors with intelligent performance on detecting target substrate in our living environment is of great significance. Two 1,8-naphthalimide fluorescence sensors with “vice” like phthalic acid recognition groups (NAC1, NAC2) were designed and synthesized via a facile method. The photophysical properties of the two compounds were investigated and compared. The research on structure-performance difference showed that NAC2, containing a n-dodecylamino group at the 4-position of the 1,8-naphthalimide moiety, had better fluorescence “turn-off” performance to Mn2+ and Zn2+. DFT calculations were applied to verify the results. NAC2 can detect the two kinds of metal ions within 1 min, and the detection limit was respectively determined to be 0.040 mg/L (for Mn2+), 0.085 mg/L (for Zn2+). NAC2 was also applied in the practical sample analysis, indicating that it is a potential visualization tool in environmental monitoring.

Rhodamine functionalized cellulose for mercury detection and removal: A strategy for providing in situ fluorimetric and colorimetric responses

A new cellulose-based material as adsorbent was prepared for Hg (II) detection and removal from aqueous solution. Rhodamine moiety was conjugated with cellulose as an efficient sensor, enabling the material to exhibit excellent optical signals on the contact with Hg (II). Fourier transform infrared spectra, elemental analysis, thermogravimetry, differential thermal analysis, scanning electron microscope analysis, Brunauer-Emmett-Teller surface area, pore volume and pore size were employed to verify the modification of cellulose. A 7-fold enhancement of fluorescence intensity afforded the adsorbent “off–on” fluorimetric response exclusively towards Hg (II) without the interference of more than ten other kinds of metal ions. The detection limit reached as low as 9.18 × 10-7 M. Besides, the adsorbent also showed an obvious color change during the adsorption to realize “naked-eye” recognition with Hg (II) in the range of 1–400 ppm. Thus, a colorimetric card was prepared to evaluate the concentration of Hg (II) in a convenient and rapid manner. In addition, the adsorption properties of the material including the effect of initial concentration, pH, and contact time were systematically investigated by batch adsorptions. The adsorption process was found to fit well with Langmuir adsorption model and pseudo-second-order kinetics. The mercury triggered spirolactam ring-opening reaction was responsible for the sensitive and selective fluormetric sensing and confirmed by the Job’s plot (1:1 binding stoichiometry) and X-ray photoelectron spectroscopy. Furthermore, density functional theory studies also indicated the energetically favorable Hg (II) induced ring-opening process. The highly sensitive and selective performance in tap water further demonstrated the tremendous potential of as-prepared adsorbent for practical application.

Adsorption of lead and cadmium by microplastics and their desorption behavior as vectors in the gastrointestinal environment

The behavior of microplastics (MPs) as vectors of environmental contaminants in aquatic systems can change the fate and transport of some toxic substances and promote their diffusion and bioenrichment. Therefore, our study investigated the adsorption of two kinds of metal ions [Pb(II) and Cd(II)] by polypropylene (PP) and polystyrene (PS) in aqueous solution and the desorption of metal ions in the gastrointestinal environment. Our findings indicated that pH, humic acid, and particle size are key factors affecting the adsorption of metal ions on MPs. The adsorption capacity of Pb(II) and Cd(II) on MPs increases as pH increases, and the presence of humic acid significantly inhibits the adsorption of metal ions on MPs. In a simulated gastrointestinal environment, the desorption rates of the two metal ions on MPs were high and controlled by the MP particle size, suggesting a possible toxicological risk for organisms after ingestion of metal-contaminated microplastics.

Simultaneous removal of lead and cadmium ions by nickel oxide nanoparticles

Objectives: To study the simultaneous removal of metal ions to understand the dynamics of the adsorption process for the assessment of the actual potential of an adsorbent in real-life applications. Methods: A one-step hydrothermal method was employed for the synthesis of nanomaterial. The hydrothermal treatment was performed at 110o C for 3 hours and calcined at 300o C for 2 hr to complete the nickel oxide nanoparticle synthesis. A systematic study of metal ion adsorption onto the nickel oxide nanoparticle was conducted to evaluate the maximum adsorption capacity and to understand the adsorption behaviour of the metal ions in presence of the others. The estimation of metal ion adsorption was done by measuring the residual concentrations using an atomic absorption spectrophotometer. Findings: The microscopic and spectroscopic characterizations confirmed the formation of nickel oxide nanostructures. The experimental results suggested that the adsorption process follows the Langmuir isotherm and the pseudo-secondorder model for metal ion adsorption in single and mixed solutions. A synergistic effect was observed for Pb (II) adsorption and an antagonistic effect for Cd (II) adsorption. The maximum adsorption capacity of ~650 mg/g of Pb (II) and ~475 mg/g of Cd (II) were noticed for simultaneous adsorption by the NiO nanoparticle. Novelty/improvement: The presence of more than one heavy metal ion in the wastewater is obvious, and one kind of metal ion may interface with the adsorption behaviour of the others. Further, limited studies on simultaneous adsorption of metal ions using metal-oxide nanoparticles are available in the literature. Hence, this work will provide an idea about the applicability of the NiO nanoparticle for real-life applications. Keywords: Adsorption; NiO; Heavy metal ions; Simultaneous removal

Simultaneous and ultra-sensitive detection of Cu2+ and Mg2+ in wine and beer based on dual DNA tweezers and entropy-driven three-dimensional DNA nanomachine

Simultaneous and ultra-sensitive detection strategy of Cu2+ and Mg2+ in wine and beer was developed based on dual DNA tweezers and entropy-driven three-dimensional DNA nanomachine. The dual DNAzyme can simultaneously respond to two kinds of metal ions and cause two kinds of “turn-on” fluorescent signals. The working principle of this strategy was indirectly proven. In addition, some key experimental parameters were also optimized. Under the optimum conditions, the limit of detection was 10 pM for Cu2+ and 2 nM for Mg2+ respectively which was significantly improved by entropy driven amplification. This strategy also showed good selectivity and specificity. It was successfully used to detect of Cu2+ and Mg2+ in wine and beer with 5.26% to 9.12% of relative standard deviation and 90.4% to 110.5% of recoveries.

Mn0.7Zn0.3Fe2O4 + BaTiO3 composites: structural, morphological, magnetic, M–E effect and dielectric properties

Here in the present investigation, constituent phases of (1 − x)Mn0.7Zn0.3Fe2O4(MZFO) + (x)BaTiO3(BTO) (where x = 0.0, 0.25, 0.50, 0.75 and 1.0) composites have been synthesized by sol–gel auto-ignition route and the composite structure by ceramic route. The XRD analysis ensures that the composite structure consists of both cubic spinel piezomagnetic and perovskite piezoelectric phases. The average crystallite size estimated from Scherrer equation increases from 15.36 to 21.94 nm. The strain induced in individual phases has been investigated by W–H analysis and it is observed that the MZFO phase shows comprehensive type strain while BTO phase shows tensile type strain. Scanning electron micrographs confirm the microstructure of the sample with grain size ranges from 36.006 to 54 nm. Energy dispersive X-ray spectra and elemental color mappings of typical samples (x = 0.0 and 0.75) clearly indicates the phase purity and stoichiometric proportion of the composites. Fourier transform infrared spectra showed five major absorption bands related to stretching vibrations of different kinds of metal ions and oxygen ions. Increasing percentage of BTO phase in the composite reduces the saturation magnetization, remnant magnetization and coercivity. Real and imaginary parts of permittivity show maximum values at lower frequency region and decrease with increase in applied frequency. For the composition (0.25)MZFO–(0.75)BTO, composite shows maximum value of magnetoelectric coupling coefficient (αME = 20.45 mVcm−1 Oe−1). The improved magnetoelectric properties make MZFO–BTO composite applicable for electronic devices.

Surface chemistry tuning the selectivity of carbon nanodots towards Hg2+ recognition

Fluorescence quenching of carbon nanodots by metal ions has been extensively applied for the determination of oligonucleotides, proteins, small molecules and metal ions. However, the problem of poor selectivity originating from the coordination of surface oxygen-containing groups to many kinds of metal ions has limited the prosperity of carbon nanodots in detection field. Herein, the specific recognition of carbon nanodots to Hg2+ is controlled by rational regulation of the surface structure of carbon nanodots. Passivation of the surface carboxyl and hydroxyl groups plays a decisive role in inhibiting the binding of metal ions with carbon nanodots. Upon the attachment of Hg2+ specific recognition unit, carbon nanodots exhibited a high selectivity to Hg2+. This work facilitates to rationally design the surface structure of carbon nanodots to obtain the desirable selective recognition ability.

Multifunctional charged hydrogel nanofibrous membranes for metal ions contained emulsified oily wastewater purification

Efficiently purifying metal ions contained emulsified oily wastewater has become a great challenge. Herein, a novel charged hydrogel nanofibrous membrane (CHNM) with negative surface charges, favorable mechanical ability and anti-fouling capacity was prepared via electrospinning and twice crosslinking process. The obtained CHNM with a surface potential of -32.9 mV at pH = 7.2 possesses outstanding oil-in-water emulsion separation performance with high permeation flux of around 10800 L h-1 m-2 bar-1 for surfactant free emulsion and high permeation flux of around 7100 L h-1 m-2 bar-1 for surfactant stabilized emulsion. The excellent oil/water emulsion separation performance can be attributed to the surface charge demulsification (SCD), which is theoretically demonstrated by a finite element analysis simulation. In addition, CHNM can absorb many kinds of metal ions (Fe3+, Ni2+ and Al3+) due to the chelation effect between high-density phosphate groups and metal ions. With outstanding separation performance for oil/water emulsion and good adsorption capacity for metal ions, the multifunctional CHNM may offer a promising approach to develop a new-generation membrane for treating metal ions contained oily wastewater.

Chitosan coordination driven self-assembly for effective delivery of curcumin

Self-assembly of metal-ligand coordination is of immense scientific interest in supramolecular construction of functional materials duo to their desirable functional properties. Herein, we investigated a designable coordination driven self-assembly to simultaneously enhance the water solubility and biological stability of curcumin (Cur). On the basis of amino group in chitosan (CS), it was chosen as the high-affinity anchors for coordination nanocomplexes, in which Cur were incorporated into the amino group by coordination bonding, forming a CS-metal-Cur architecture. The sizes of these nanocomplexes can be tuned by the feed concentrations of CS as well as the kind of metal ions. Time dependent absorption spectral measurements demonstrated the significant increase in hydrolytic stability of Cur after forming nanoparticles (NPs) especially for the CS-Cu-Cur NPs. Particularly, the formed CS-metal-Cur NPs can be efficiently triggered by pH, which was stable under physiological conditions while releasing encapsulated drugs under low pH conditions in a sustained manner. Based on cellular uptake study and cytotoxicity experiments, CS-metal-Cur NPs were shown to possess highly efficient internalization and an apparent cytotoxic effect. The high drug-loading capacities and responses to pH value, substantially enhanced antitumor activity of Cur provided this nanocomplex with promising properties for biomimetic and biomedical applications.

“Turn-on” far-red fluorescence sensor for Y3+ based on Schiff-based tetraphenylethylene

Far-red and “turn-on” fluorescence sensors were paid much attention due to their outstanding merits, but this kind of fluorescence probe for Y3+ was not presented up to date. In this work, a Schiff-base bridged m-aminobenzoic acid-decorating tetraphenylethylene was designed and synthesized in yield of 89%. It exhibited the far-red fluorescence at 550–670 nm in aqueous media based on AIE effect. It showed high selective sensing ability for Y3+ among all kinds of metal ions with the obvious “turn-on” fluorescence, which was observed for the first time for fluorescence sensor of Y3+. The detection limit for Y3+ was as low as 2.23 × 10−7 M. The sensor mechanism of 1:1 stoichiometric ratio was clarified by fluorescence titration, FT-IR spectra, 1H NMR and MS spectra. The selective sensing of Y3+ was further successfully applied on detecting Y3+ for tested paper, simulated water sample and bio-imaging of live cells, suggesting the good practical application potential of this fluorescence sensor on detecting Y3+ in complicated water media and living body environment.

Fluorescent sensor array for selective recognition of biothiols

Biological thiols play essential roles in life activities. Detection and differentiation of different biothiols is of crucial need in biomedical research and diagnostics. Herein, a novel fluorescent sensor array was constructed to discriminate six kinds of biothiols including Cysteine (Cys), N-acetylcystein (NAC), 2-mercaptoethanol (MCE), Homocysteine (Hcy), Glutathione (GSH), and Glutathione disulfide (GSSG) simultaneously. This sensor array was fabricated by using three kinds of metal ions (i.e., Fe3+, Ni2+, and Cu2+)–N-CDs pairs. The N-CDs were synthesized with urea as nitrogen sources and folic acid as carbon sources via a simple microwave approach. Based on the competitive interactions of N-CDs with metal ions and thiols, the sensor array exhibits diverse fluorescence intensity response patterns, six thiols could be effectively and simultaneously differentiated in a wide concentration range (≧50 μM) by principal component analysis (PCA). Morover, double-blind samples of biothiols were recognized with 97.2% accuracy through linear discrimination analysis (LDA). More importantly, the sensor array showed good practicability in complex media such as fetal bovine serum, demonstrating this proposed sensor array held a great potential for the identification of biological thiols in real samples.

Siderophore Production by Rhizosphere Biological Control Bacteria Brevibacillus brevis GZDF3 of Pinellia ternata and Its Antifungal Effects on Candida albicans.

Brevibacillus brevis GZDF3 is a gram-positive, plant growth-promoting rhizosphere bacterium (PGPR) isolated from the rhizosphere soil of Pinellia ternata (an important herb in traditional Chinese medicine). The GZDF3 strain produces certain active compounds, such as siderophores, which are the final metabolite products of non-ribosomal peptide synthetase (NRPS) and independent non-ribosomal peptide synthetase (NIS) activity. With the present study, we attempted to investigate the siderophore production characteristics and conditions of Bacillus sp. GZDF3. The antibacterial activity of the siderophores on pathogenic fungi was also investigated. Optimal conditions for the synthesis of siderophores were determined by single factor method, using sucrose 15 g/l, asparagine 2 g/l, 32°C, and 48 h. The optimized sucrose asparagine medium significantly increased the production of siderophores, from 27.09% to 54.99%. Moreover, the effects of different kinds of metal ions on siderophore production were explored here. We found that Fe3+ and Cu2+ significantly inhibited the synthesis of siderophores. The preliminary separation and purification of siderophores by immobilized-metal affinity chromatography (IMAC) provides strong antibacterial activity against Candida albicans. The synergistic effect of siderophores and amphotericin B was also demonstrated. Our results have shown that the GZDF3 strain could produce a large amount of siderophores with strong antagonistic activity, which is helpful in the development of new biological control agents.