Chemiluminescence and energy transfer mechanism of lanthanide ions in different media based on peroxomonosulfate system

The chemiluminescence (CL) phenomena of lanthanide (Ln) ions and their coordinate complexes in peroxomonosulfate system and the energy transfer mechanism during the process were investigated in this work. A strong and sharp CL signal was yielded when the Eu(III) or Tb(III) solution was added to the peroxymonosulfate solution. The CL intensity was greatly enhanced by 2,6‐pyridinedicarboxylic acid (DPA) ligand [maximum enhancement reached when Ln(III):DPA was 1:1] and hexadecyltrimethylammonium chloride micelles. The degree of enhancement of DPA and micelles on Ln(III) CL was related to the fluorescence lifetimes of Ln(III) in different media. According to the ESR spin‐trapping experiments of 2,2,6,6‐tetramethyl‐4‐piperidone and the specific quenching experiments of 1,4‐diazabicyclo[2.2.2]octane and sodium azide, singlet oxygen was generated though the Ln(III) ion‐catalyzed decomposition of peroxymonosulfate. From the comparisons of the fluorescence and CL spectra, lanthanide ions were the luminescence emitter and the ligand DPA absorbed the energy from singlet oxygen and transferred it to Ln(III) ions in the coordinate complexes. Micelles can enhance the CL intensity by improving intermolecular energy transfer efficiencies, removing the quenching effect of water and prolonging the lifetime of singlet oxygen. Copyright © 2009 John Wiley & Sons, Ltd.     

pH dependence of the enantioselective excited-state quenching of Λ,Δ-Tb(III) and Λ,Δ-Eu(III)tris(pyridine-2,6-dicarboxylate) chelates by ferricytochrome c from horse heart and ferricytochrome c-550 from Paracoccus versutus

 The pH dependence of the dynamic quenching of the luminescence from Tb(III) and Eu(III) tris(pyridine-2,6-dicarboxylate≡DPA) chelates by the title proteins is studied. For Tb(DPA)₃ ^3– also the quenching by the Lys 14→Glu and Lys99→Glu mutants of cytochrome c-550 (cytc-550) is investigated. The rate constants for quenching of the electronically excited Λ and Δ enantiomers of the luminophore by equine cytochrome c show a sharp decrease upon increasing the pH from 7 to 10, which can be described phenomenologically by deprotonation of a single acidic group with pK _a of 9.2±0.1 for Eu and 9.4±0.1 for Tb. These values are similar to that found for the alkaline transition of the protein. The alkaline conformer(s) of the protein at pH>10 is found to be a very inefficient quencher of the lanthanide luminescence. For Tb, but not for Eu, a significant lowering of the degree of enantioselectivity (E _q) in the quenching is found along with a reduction of the quenching rates. For cytc-550, the decrease of the quenching rate constants with increasing pH is described by pK _a=9.8±0.1 and for the two mutants the same value is obtained. For the cytc-550 proteins the change of the quenching rates does not correlate with the alkaline transition, for which a pK _a of 11.2 has been reported by other workers. For all proteins, the reduction of the quenching rates at high pH is ascribed to a reduction of the binding affinity of the excited lanthanide complex to the surface area of the protein near the exposed heme edge, caused by deprotonation of (presumably) several lysine residues. Received: 3 April 1998 / Accepted: 15 June 1998     

Syntheses and luminescent properties of a copolymer of terbium‐p‐aminobenzoic acid–methacrylic acid and styrene

A reactive Tb(III) complex with p‐aminobenzoic acid (p‐ABA) and methacrylic acid (MAA) as ligands was synthesized. A novel copolymer was synthesized by free radical copolymerization of styrene and the reactive Tb(III) complex in dimethyl sulfoxide (DMSO) with 2,2′‐azobis(2‐methylpropionitrile) (AIBN) as the initiator. IR and UV/Vis spectra indicate that the copolymer exhibited absorption from polystyrene and the complex. Thermogravimetric analysis indicates that the copolymer remained stable up to 357°C and the thermal stability was significantly improved in comparison with polymer matrix and the Tb(III) complex. The luminescent intensity of the synthetic terbium macromolecular complexes increased with increasing complex monomer content. Moreover, concentration quenching was not observed. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and luminescence properties of lanthanide complexes with a new tripodal ligand featuring N‐thenylsalicylamide arms

To explore the relationship between the structure of the ligands and the luminescent properties of the lanthanide complexes, luminescent lanthanide complexes of a new tripodal ligand, featuring N‐thenylsalicylamide arms, were synthesized and characterized by elemental analysis, IR and TGA measurements. Photophysical properties of the complexes were studied by means of UV ? visible absorption and steady‐state luminescence spectroscopy. The results of UV ? vis spectra indicate that metal binding does not disturb the electronic structure of the ligand. Excited‐state luminescence lifetimes and quantum yields of the complexes were determined. The photoluminescence analysis suggested that there is an efficient ligand ? Ln(III) energy transfer for the Tb(III) complex, and the ligand is an efficient 'antenna' for Tb(III). From a more general perspective, the results demonstrated the potential application of the lanthanide complex as luminescent materials in material chemistry. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis and luminescence properties of two novel lanthanide (III) complexes of acetophenonylcarboxymethyl sulphoxide

A novel ligand containing multiple coordinating groups (sulfinyl, carboxyl and carbonyl groups), acetophenonylcarboxymethyl sulphoxide, was synthesized. Its corresponding two lanthanide (III) binary complexes were synthesized and characterized by element analysis, molar conductivity, FT‐IR, TG‐DTA and UV spectroscopy. Results showed that the composition of these complexes was REL₃L^‐ (ClO₄)₂·3H₂O (RE = Eu (III), Tb (III); L = C₆H₅COCH₂SOCH₂COOH; L^‐ = C₆H₅COCH₂SOCH₂COO^‐). FT‐IR results indicated that acetophenonylcarboxymethyl sulphoxide was bonded with an RE (III) ion by an oxygen atom of the sulfinyl and carboxyl groups and not by an oxygen atom of the carbonyl group due to high steric hinderance. Fluorescent spectra showed that the Tb (III) complex had excellent luminescence as a result of a transfer of energy from the ligand to the excitation state energy level (⁵D₄) of Tb (III). The Eu (III) complex displayed weak luminescence, attributed to low energy transfer efficiency between the triplet state energy level of its ligand and the excited state (⁵D₀) of Eu (III). As a result, the Tb (III) complex displayed a good antenna effect for luminescence. The fluorescence decay curves of Eu (III) and Tb (III) complexes were also measured. Copyright © 2012 John Wiley & Sons, Ltd.     

Acetylcholinesterase‐Inhibitory Activities of the Extracts from Sponges Collected in Mauritius Waters

Patients diagnosed with Alzheimer's disease (AD) show a characteristic neurochemical deficit of acetylcholine, especially in the basal forebrains. The use of acetylcholinesterase (AChE) inhibitors to retard the hydrolysis of acetylcholine has been suggested as a promising strategy for AD treatment. In this study, we evaluated the acetylcholinesterase inhibitory (AChEI) activities of 134 extracts obtained from 45 species of marine sponges. Thin‐layer chromatography (TLC) and microplate assays reveal potent acetylcholinsterase inhibitory activities of two AcOEt extracts from the sponges Pericharax heteroraphis and Amphimedon navalis Pulitzer‐Finali . We further investigated the inhibitory kinetics of the extracts and found them to display mixed competitive/noncompetitive inhibition and associated their inhibitory activity partly to terpenoids. Acetylcholinesterase inhibitors from marine organisms have been rarely studied, and this study demonstrated the potential of marine sponges as a source of pharmaceutical leads against neurodegenerative diseases.     

Luminescence quenching by nitroxide spin labels in aqueous solution: studies on the mechanism of quenching.

The mechanism of luminescence quenching by spin labels was investigated in aqueous solution by steady-state and time-resolved luminescence techniques. Water-soluble nitroxide radicals strongly quenched the luminescence emitted by Tb3+ chelates and by fluorescein, either free or conjugated to proteins. The following features of the quenching reaction were established: (I) the rate constant for quenching of triplet-state Tb3+ by nitroxides was about 4 orders of magnitude smaller (ca. 10(5) M-1 s-1) than those of the singlet-state probes; (II) the quenchers reduced the excited-state lifetime of both probes; (III) the rate constants for quenching of both probes were found to be apparently independent of the temperature (between 6 and 42 degrees C) and viscosity (up to 60 mPa.s) of the solutions; (IV) both singlet and triplet quenching rates were sensitive to solvent polarity; (V) there is a small but significant spectral overlap between the absorption band of weekly absorbing nitroxide radicals and the emission spectra of luminophores, the extent of which, however, does not correlate with the extent of quenching; (VI) the quenching rate declines sharply with an increasing luminophore to nitroxide distance. The distance dependence of the quenching rate showed a satisfactory fit to an exponential function. These findings indicate that the quenching reaction is dominated by an electron exchange between the excited singlet- or triplet-state luminophore and the nitroxide radical rather than controlled by diffusional properties of the reactants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Species differences in the negative inotropic effect of acetylcholine and soman in rat,guinea pig,and rabbit hearts

1. Acetylcholine reduced atrial contractions by 82.5% in guinea pig, 50.8% in rat, and 41.5% in rabbit.2. The EC₅₀ values for the negative inotropic effect of acetylcholine were 3.3 × 10⁻⁷ M in rat and guinea pig atria and 4.1 × 10⁻⁶ M in rabbit atria.3. There was no correlation between the species differences in the negative inotropic effect of acetylcholine in atria and the density or affinity of acetylcholinesterase or muscarinic receptors.4. Inhibition of atrial acetylcholinesterase with soman reduced the ec₅₀of acetylcholine three-fold in all species, but did not change the maximal inotropic effect of acetylcholine.5. Species differences in the negative inotropic effect of acetylcholine may be caused by differences in the coupling between myocardial muscarinic receptors and the ion channels that mediate negative inotropy.     

Oxygen quenching of sensitized terbium luminescence in complexes of terbium with small organic ligands and proteins

Oxygen does not quench the luminescence of either free Tb or of Tb bound to dipicolinate. However, sensitized Tb luminescence in complexes of that ion with elastase, thermolysin, and alpha-amylase is quenched by oxygen at rates that far exceed that with which the intrinsic fluorescence of the proteins is quenched. We infer that this more rapid quenching of Tb luminescence indicates a major role for energy transfer from tryptophan moieties in a triplet excited state.     

Spectroscopic studies of metal ion binding to a tryptophan-containing parvalbumin

The binding of Ca(II) and members of the trivalent lanthanide ion, Ln(III), series to apoparvalbumin (isotype pI = 4.75) from codfish (Gadus callarius L) results in the development of a distinctive sharp feature in the UV absorption spectrum at about 290 nm. Titration curves obtained by monitoring the spectral change in this region reveal a change in slope after the addition of 1 equiv of metal ion and no further rise after 2 equiv has been added, consistent with sequential binding to the principal EF and CD sites. Laser-induced luminescence excitation spectra of the 7F0----5D0 transition of bound Eu(III) demonstrate the quantitative binding of this ion to the principal sites and disclose the presence of a subsidiary site at pH values greater than 6. Metal ion competition experiments monitored by means of this excitation transition show that the early members of the Ln(III) ion series bind more tightly than those at the end. Tryptophan-sensitized Tb(III) luminescence reveals that this ion binds sequentially to the EF and CD sites, in that order. The intrinsic tryptophan fluorescence of apoparvalbumin is increased in a stepwise fashion as Ca(II) or Ln(III) ions bind sequentially, with the exceptions of Eu(III) and Yb(III). The binding of the latter two ions causes quenching of the protein fluorescence via an energy-transfer process which involves low-lying charge-transfer bands. The distance dependences of the tryptophan to Tb(III) and tryptophan to Eu(III) energy-transfer processes are observed to be identical, consistent with a F?rster-type mechanism in both cases.     

Species differences in the negative inotropic effect of acetylcholine and soman in rat, guinea pig, and rabbit hearts.

1. Acetylcholine reduced atrial contractions by 82.5% in guinea pig, 50.8% in rat, and 41.5% in rabbit. 2. The EC50 values for the negative inotropic effect of acetylcholine were 3.3 x 10(-7) M in rat and guinea pig atria and 4.1 x 10(-6) M in rabbit atria. 3. There was no correlation between the species differences in the negative inotropic effect of acetylcholine in atria and the density or affinity of acetylcholinesterase or muscarinic receptors. 4. Inhibition of atrial acetylcholinesterase with soman reduced the EC50 of acetylcholine three-fold in all species, but did not change the maximal inotropic effect of acetylcholine. 5. Species differences in the negative inotropic effect of acetylcholine may be caused by differences in the coupling between myocardial muscarinic receptors and the ion channels that mediate negative inotropy.     

Luminescence studies of lanthanide ion binding to parvalbumin

Luminescence methods were used to examine the interaction of Eu(III) and Tb(III) with parvalbumin isozyme III from pike (Esox lucius). The bound lanthanide ions were excited both directly, via laser irradiation, and indirectly, via fluorescence energy transfer from adjacent phenylalanine residues. At high (175 microM) protein concentrations, the lanthanide titration curves exhibited pronounced quenching of luminescence at Ln3+:parvalbumin ratios above 2:1, in agreement with earlier reports (Donato, H., Jr., and Martin, R. B. (1974) Biochemistry 13, 4575-4579). However, in experiments performed with lower concentrations (10 microM), the titrations were well behaved and indicated a lanthanide:protein stoichiometry of 2:1. Equilibrium dialysis measurements performed with Eu(III) ruled out the existence of a third strong binding site which could cause the quenching of the luminescence at high protein concentrations. Similarly, careful analysis of the spectrum that results from direct excitation of the 7F0----5D0 transition of parvalbumin-bound Eu3+ ion revealed no peak attributable to a third Ln3+-binding site. The peak which has been construed by others (Rhee, M.-J., Sudnick, D. R., Arkle, V. K., and Horrocks, W. DeW., Jr. (1981) Biochemistry 20, 3328-3334) as evidence for a third site was shown to result from a pH-dependent spectral transition involving the europium ions bound at the CD and EF sites. Luminescent lifetime measurements performed on Tb(III)/parvalbumin solutions follow Stern-Volmer quenching kinetics at terbium:protein ratios in excess of 2:1, suggesting that the quenching results from collisional deactivation of the tightly bound ions by excess terbium ion free in solution.     

Synthesis and luminescence properties of polymer–rare earth complexes containing salicylaldehyde‐type bidentate Schiff base ligand

Using molecular design and polymer reactions, two types of bidentate Schiff base ligands, salicylaldehyde–aniline (SAN) and salicylaldehyde–cyclohexylamine (SCA), were synchronously synthesized and bonded onto the side chain of polysulfone (PSF), giving two bidentate Schiff base ligand‐functionalized PSFs, PSF–SAN and PSF–SCA, referred to as macromolecular ligands. Following coordination reactions between the macromolecular ligands and Eu(III) and Tb(III) ions (the reaction occurred between the bonded ligands SAN or SCA and the lanthanide ion), two series of luminescent polymer–rare earth complexes, PSF–SAN–Eu(III) and PSF–SCA–Tb(III), were obtained. The two macromolecular ligands were fully characterized by Fourier transform infrared (FTIR), ¹H NMR and UV absorption spectroscopy, and the prepared complexes were also characterized by FTIR, UV absorption spectroscopy and thermo‐gravity analysis. On this basis, the photoluminescence properties of these complexes and the relationships between their structure and luminescence were investigated in depth. The results show that the bonded bidentate Schiff base ligands, SAN and SCA, can effectively sensitize the fluorescence emission of Eu(III) and Tb(III) ions, respectively. PSF–SAN–Eu(III) series complexes, namely the binary complex PSF–(SAN)₃–Eu(III) and the ternary complex PSF–(SAN)₃–Eu(III)–(Phen)₁ (Phen is the small‐molecule ligand 1,10‐phenanthroline), produce strong red luminescence, suggesting that the triplet state energy level of SAN is lower and well matched with the resonant energy level of the Eu(III) ion. By contrast, PSF–SAN–Eu(III) series complexes, namely the binary complex PSF–(SCA)₃–Tb(III) and the ternary complex PSF–(SCA)₃–Tb(III)–(Phen)₁, display strong green luminescence, suggesting that the triplet state energy level of SCA is higher and is well matched with the resonant energy level of Tb(III).     

Terbium(III) luminescence study of the spatial relationship of tryptophan residues to the two metal ion binding sites of Escherichia coli glutamine synthetase.

The luminescence of Tb(III) was used to explore the topography of the metal ion sites of Escherichia coli glutamine synthetase and the relationship between these sites and tryptophan residues of the enzyme. By irradiation of tryptophan residues at 295 nm and measurement of the resulting Tb(III) luminescence at 544 nm, a biphasic curve was obtained upon titrating apoenzyme with Tb(III) indicating sequential binding of Tb(III) ions to the two binding sites of glutamine synthetase. The luminescence intensity was greater in the second region of the titration curve which is mostly due to energy transfer from Trp-158 to the second Tb(III) binding site of the enzyme. By use of the F?rster equation for energy transfer from donor Trp to acceptor Tb(III), distances from Trp-57 to Tb(III) at the n1 and n2 sites were calculated, by using a mutant enzyme in which Trp-158 was replaced by Ser, to be 16.4 and 15.7 A, respectively; distances from Trp-158 to Tb(III) at the n1 and n2 sites were calculated, by using a mutant enzyme in which Trp-57 was replaced by Leu, to be 16.8 and 9.5 A, respectively. All the distances are in reasonably good agreement with the crystal structure distances from Salmonella typhimurium glutamine synthetase except the distance from Trp-158 to the second Tb(III) binding site. The discrepancies may result from a slightly different conformation of glutamine synthetase in solution and in the crystal and/or a slightly different conformation for trivalent Ln(III) binding compared to divalent Mn(II) binding.     

Fluorescence enhancement of rare earth Tb(III) by Tm(III) in benzyl benzoylmethyl sulphoxide complexes

A series of rare earth complexes [(Tb_xTm_y)L₅(ClO₄)₂](ClO₄)·3H₂O (x:y = 1.000:0.000, 0.999:0.001, 0.995:0.005, 0.990:0.010, 0.950:0.050, 0.900:0.100, 0.800:0.200, 0.700:0.300; L = C₆H₅CH₂SOCH₂COC₆H₅) (Tb(III) luminescence ion; Tm(III) doped inert ion) were synthesized and characterized by elemental analysis, infrared spectra (IR) and ¹H‐NMR. The photophysical properties of these complexes were studied in detail using ultraviolet absorption spectra, fluorescent spectra and lifetimes. The fluorescence spectra of complexes indicated that the fluorescence emission intensity was significantly enhanced by Tm(III). The complexes showed the best luminescence properties when the mole ratio Tb(III):Tm(III) was 0.990:0.010. The fluorescence intensity could be increased to 390%. Additionally, phosphorescence spectra and the luminescence mechanisms are discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Steady-state luminescence investigation of the binding of Eu(III) and Tb(III) ions with synthetic peptides derived from plant thionins

This work reports Eu(III) and Tb(III) luminescence titrations in which the lanthanide ions were used as spectroscopic probes for Ca(II) ions to determine the metal binding ability of Ac-NESVKEEGGW-NH(2) and Ac-NESVKEDGGW-NH(2). These decapeptides correspond to the putative calcium binding region of the plant antifungal proteins SI-alpha1 from Sorghum bicolor and of Zeathionin from Zea mays, respectively. The luminescence spectra for the Eu(III)-decapeptide system (red emission) with the excitation at the Trp band at 280 nm showed an enhancement of the intensities of the 5D(0)-->7F(J) transitions (where J=0-4) with increments of Eu(III) ion concentration. The photoluminescence titration data of the terbium ion (green emission) in the decapeptide solutions showed intensification of the 5D(4)-->7F(J) transitions (J=0-6), similar to that observed for the Eu(III) ion. Thus, energy transfer from Ac-NESVKEEGGW-NH(2) and Ac-NESVKEDGGW-NH(2) to the trivalent lanthanide ions revealed that these peptides are capable of binding to these metal ions with association constants of the order of 10(5) M(-1). The amino acid derivative Ac-Trp-OEt also transferred energy to Tb(III) and Eu(III) ions as judged from the quenching of tryptophan luminescence. However, the energy transfers were significantly lower. Taken together the luminescence titration data indicated that Ac-NESVKEEGGW-NH(2) and Ac-NESVKEDGGW-NH(2) bind efficiently to both trivalent lanthanide ions and that these ions may be used as probes to distinguish an anionic peptide from a neutral amino acid derivative.     

Quenching of graphene quantum dots fluorescence by alkaline phosphatase activity in the presence of hydroquinone diphosphate

In this work, a turn‐off photoluminescent sensing proof‐of‐concept based on blue luminescent graphene quantum dots (GQDs) as the fluorescent probe was developed. For that purpose, GQDs optical response was related with the catalytic enzymatic activity of alkaline phosphatase (ALP), in the presence of hydroquinone diphosphate (HQDP). The hydrolysis of HQDP by ALP generated hydroquinone (HQ). The oxidation of HQ, enzymatically produced, to p‐benzoquinone (BQ) resulted in the quenching of GQDs fluorescence (FL). Therefore, the developed luminescent sensing mechanism allowed the FL quenching with ALP activity to be related and thus quantified the concentration of ALP down to 0.5 nM of enzyme. This innovative design principle appears as a promising tool for the development of enzymatic sensors based on ALP labeling with fluorescent detection or even for direct ALP luminescent quantification in an easy, fast and sensitive manner.     

An ultrasensitive electrometric system to measure membrane-bound acetylcholinesterase activity

A very sensitive method for the determination of membrane-bound acetylcholinesterase from sarcoplasmic reticulum is described. The acetic acid which is released by the enzymatic hydrolysis of acetylcholine is measured by means of an electrometric system. Diluted hydrochloric acid is used as the standard to evaluate the amount of H+ produced during the time course of the reaction. With the use of a bucking voltage device the sensitivity of the method permits one to follow changes in H+ concentration below 1 microM. Therefore the enzyme activity can be estimated using a very small amount of sarcoplasmic reticulum protein. This procedure is very simple, accurate and reproducible, and it can be applied to measure membrane-bound acetylcholinesterase where the membrane suspension makes it difficult to employ spectrophotometric techniques.     

Synthesis,density functional theory calculations and luminescence of lanthanide complexes with 2,6‐bis[(3‐methoxybenzylidene)hydrazinocarbonyl] pyridine Schiff base ligand

A pyridine‐diacylhydrazone Schiff base ligand, L = 2,6‐bis[(3‐methoxy benzylidene)hydrazinocarbonyl]pyridine was prepared and characterized by single crystal X‐ray diffraction. Lanthanide complexes, Ln–L, {[LnL(NO₃)₂]NO₃.xH₂O (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Er)} were prepared and characterized by elemental analysis, molar conductance, thermal analysis (TGA/DTGA), mass spectrometry (MS), Fourier transform infra‐red (FT‐IR) and nuclear magnetic resonance (NMR) spectroscopy. Ln–L complexes are isostructural with four binding sites provided by two nitro groups along with four coordination sites for L. Density functional theory (DFT) calculations on L and its cationic [LnL(NO₃)₂]⁺ complexes were carried out at the B3LYP/6–31G(d) level of theory. The FT‐IR vibrational wavenumbers were computed and compared with the experimentally values. The luminescence investigations of L and Ln–L indicated that Tb–L and Eu–L complexes showed the characteristic luminescence of Tb(III) and Eu(III) ions. Ln–L complexes show higher antioxidant activity than the parent L ligand.     

Multispectroscopic DNA-binding studies of a terbium(III) complex containing 2,2′-bipyridine ligand

Agarose gel electrophoresis, absorption, fluorescence, viscosity, and circular dichroism (CD) have been used in exploring the interaction of terbium(III) complex, [Tb(bpy)₂Cl₃(OH₂)] where bipy is 2,2′-bipyridine, with Fish salmon DNA. Agarose gel electrophoresis assay, along with absorption and fluorescence studies, reveal interaction between the corresponding complex and FS-DNA. Also, the binding constants (K_b) and the Stern–Volmer quenching constants (K_sv) of Tb(III) complex with FS-DNA were determined. The calculated thermodynamic parameters suggested that the binding of mentioned complex to FS-DNA was driven mainly by hydrophobic interactions. A comparative study of this complex with respect to the effect of iodide-induced quenching, ionic strength effect, and ethidium bromide exclusion assay reflects binding of explicit to the FS-DNA primarily in a groove fashion. CD and viscosity data also support the groove binding mode. Furthermore, Tb(III) complex have been simultaneously screened for their antibacterial and antifungal activities.