Development of a ratiometric time-resolved luminescence sensor for pH based on lanthanide complexes

Time-resolved luminescence bioassay technique using lanthanide complexes as luminescent probes/sensors has shown great utilities in clinical diagnostics and biotechnology discoveries. In this work, a novel terpyridine polyacid derivative that can form highly stable complexes with lanthanide ions in aqueous media, (4′-hydroxy-2,2′:6′,2′′-terpyridine-6,6′′-diyl) bis(methylenenitrilo) tetrakis(acetic acid) (HTTA), was designed and synthesized for developing time-resolved luminescence pH sensors based on its Eu³⁺ and Tb³⁺ complexes. The luminescence characterization results reveal that the luminescence intensity of HTTA–Eu³⁺ is strongly dependent on the pH values in weakly acidic to neutral media (pK_a = 5.8, pH 4.8–7.5), while that of HTTA–Tb³⁺ is pH-independent. This unique luminescence response allows the mixture of HTTA–Eu³⁺ and HTTA–Tb³⁺ (the HTTA–Eu³⁺/Tb³⁺ mixture) to be used as a ratiometric luminescence sensor for the time-resolved luminescence detection of pH with the intensity ratio of its Tb³⁺ emission at 540 nm to its Eu³⁺ emission at 610 nm, I_540 nm/I_610 nm, as a signal. Moreover, the UV absorption spectrum changes of the HTTA–Eu³⁺/Tb³⁺ mixture at different pHs (pH 4.0–7.0) also display a ratiometric response to the pH changes with the ratio of absorbance at 290 nm to that at 325 nm, A_290 nm/A_325 nm, as a signal. This feature enables the HTTA–Eu³⁺/Tb³⁺ mixture to have an additional function for the pH detection with the absorption spectrometry technique. For loading the complexes into the living cells, the acetoxymethyl ester of HTTA was synthesized and used for loading HTTA–Eu³⁺ and HTTA–Tb³⁺ into the cultured HeLa cells. The luminescence imaging results demonstrated the practical utility of the new sensor for the time-resolved luminescence cell imaging application.     

Effect of Tb3+ concentration in the visible emission of terbium-doped gadolinium oxysulfide microspheres

Experimental data obtained from optical characterization of Gd₂O₂S:Tb³⁺ microspheres were compared with a rate-equation model in order to understand and simulate the emission intensity and color tonality as a function of Tb³⁺ concentration. The microparticles were prepared by hydrothermal synthesis and characterized by TEM and XRD to confirm spherical microparticles with a hexagonal lattice. Furthermore, fluorescent spectroscopy and rate equation model revealed that the direct energy transfer between Gd³⁺→Tb³⁺ ions and the migration of the excitation energy between Tb³⁺ play an important role in the luminescence intensity, while the color tonality is mainly governed by the non-radiative relaxation processes between Tb³⁺ at low concentrations. Finally, our results suggest that the rate equation model provides an efficient alternative to estimate theoretically the maximum doping concentration in oxysulfides before they present quenching of luminescence.     

A new promising phosphor, Na3La2(BO3)3:Ln (Ln=Eu, Tb)

We present an efficient way to search a host for ultraviolet (UV) phosphor from UV nonlinear optical (NLO) materials. With the guidance, Na₃La₂(BO₃)₃ (NLBO), as a promising NLO material with a broad transparency range and high damage threshold, was adopted as a host material for the first time. The lanthanide ions (Tb³⁺ and Eu³⁺)-doped NLBO phosphors have been synthesized by solid-state reaction. Luminescent properties of the Ln-doped (Ln=Tb³⁺, Eu³⁺) sodium lanthanum borate were investigated under UV ray excitation. The emission spectrum was employed to probe the local environments of Eu³⁺ ions in NLBO crystal. For red phosphor, NLBO:Eu, the measured dominating emission peak was at 613 nm, which is attributed to ⁵D₀-⁷F₂ transition of Eu³⁺. The luminescence indicates that the local symmetry of Eu³⁺ in NLBO crystal lattice has no inversion center. Optimum Eu³⁺ concentration of NLBO:Eu³⁺ under UV excitation with 395 nm wavelength is about 30 mol%. The green phosphor, NLBO:Tb, showed bright green emission at 543 with 252 nm excited light. The measured concentration quenching curve demonstrated that the maximum concentration of Tb³⁺ in NLBO was about 20%. The luminescence mechanism of Ln-doped NLBO (Tb³⁺ and Eu³⁺) was analyzed. The relative high quenching concentration was also discussed.     

Mg2[BN2]Cl and Mg8[BN2]5I: Novel Magnesium Nitridoborate Halides — Syntheses,Crystal Structures,and Vibrational Spectra

The title compounds have been synthesized at 1473 K from stoichiometric mixtures of the binary components Mg₃N₂, MgX₂ (X = Cl, I) and BN in arc‐welded steel ampoules encapsulated in evacuated silica tubes. Mg₂[BN₂]Cl ( 1 ) and Mg₈[BN₂]₅I ( 2 ) crystallize in the orthorhombic space groups Pbca (no. 61) and Imma (no. 74), respectively, with a = 6.6139(8)Å, b = 9.766(1)Å, c = 10.600(1)Å, Z = 8 for 1 and a = 13.535(3)Å, b = 9.350(2)Å, c = 11.194(2)Å, Z = 4 for 2 . The crystal structures are characterized mainly by Mg₆ trigonal prisms which are condensed to 3D frameworks in different ways. Part of the trigonal prisms are centered by the [N—B—N]^3— anions and other voids in the framework by the X^— anions. The magnesium environment around Cl^— is a very distorted monocapped trigonal prism (CN = 6+1) and that of I^— is a bicapped heptagonal prism (CN = 14+2). The bond lengths and bond angles for the relevant [BN₂]^3— anions are d(B—N) = 1.330 — 1.338Å, ∠N—B—N = 175.8° in 1 and d(B—N) = 1.330 — 1.339Å, ∠N—B—N = 176.8° — 178.0° in 2 . The vibrational spectra of the title compounds have been recorded and interpreted based on the D_∞h symmetry of the relevant [N—B—N]^3— groups considering the site symmetry splitting.     

Exceptionally Long‐Lived Luminescence Emitted from TbIII Ion Caged in an AgI–TbIII–Thiacalix[4]arene Supramolecular Complex in Water

The compositions and photophysical properties of luminescent ternary complexes of thiacalix[4]arene‐p‐sulfonate (TCAS), Tb^III, and Ag^I ions were determined. At pH 6, Ag^I₂?Tb^III₂?TCAS₂ formed. Moreover, at pH 10, in the presence of a 20‐fold excess of Ag^I and a 50‐fold excess of TCAS with respect to Tb^III, Ag^I₂?Tb^III?TCAS₂ formed as the main luminescent species. The structure of these complexes was proposed: two TCAS ligands are linked by two S–Ag^I–S linkages to adopt a double‐cone supramolecular structure. Furthermore, each Tb^III ion in the former complex accepts O^?, S, O^? donation, whereas in the latter, the Tb^III center accepts eightfold O^? donation. The luminescence quantum yield (Φ) of Ag^I₂?Tb^III₂?TCAS₂ (0.16) was almost equal to that of Tb^III?TCAS, but the luminescence lifetime τ of the former (=1.09 ms) was larger than that of the latter. For Ag^I₂?Tb^III?TCAS₂, the yield Φ (=0.11) was small, which is attributed to the low efficiency of photosensitization (η=0.11). However, the τ value (4.61 ms) was exceptionally large and almost equal to the natural luminescence lifetime of Tb^III (4.7 ms), which is due to the absence of coordinating water molecules (q=0.1). This is compatible with the proposed structure in which the Tb^III ion is shielded by a supramolecular cage that expels coordinated water molecules responsible for luminescence quenching.     

Terbium sensitized luminescence for the determination of fexofenadine in pharmaceutical formulations

A sensitive and specific luminescence method for the determination of Fexofenadine (FEX), in pharmaceutical formulations is reported. The method is based on the sensitization of terbium (Tb³⁺) by complex formation with FEX. The luminescence signal for Tb–FEX complex is greatly enhanced by the addition of triethylamine (ET₃N) and zinc nitrate in methanol solution. Monitoring of the signal is accomplished when the instrument is in the phosphorescence mode with the excitation and emission wavelengths set at λ_ex = 220 nm and λ_em = 550 nm respectively. Optimum conditions for the formation of the complex in methanol were 2.25 × 10^?6 M of Tb³⁺, 5.00 × 10^?6 M of Et₃N and Zn²⁺ which allows for the determination of 10–800 ppb of FEX in the batch mode with a detection limit of 0.3 ppb. The proposed method was successfully applied for the determination of FEX in pharmaceutical formulations.     

Crystal structure and triboluminescence of the [Tb(BTFA)2(NO3)(TPPO)2] complex

The crystal structure of the [Tb(BTFA)₂(NO₃)(TPPO)₂] complex (TPPO is triphenylphosphine oxide, BTFA is benzoyltrifluoracetone), which exhibits strong triboluminescence, has been established by X-ray crystallography. The crystals are triclinic: a = 11.668(3) Å, b = 11.700(3) Å, c = 12.512(3) Å, α = 65.161(4°), β = 79.120(4)°, γ = 61.860(4)°, space group P1, Z = 1. The central terbium(III) atom coordinates two oxygen atoms from two triphenylphosphine oxide molecules (Tb-O, 2.264(3) and 2.273(3) Å), two oxygen atoms from the nitrate group (Tb-O, 2.460(3) and 2.476(3) Å), and four oxygen atoms from two benzoyltrifluoroacetonate groups (Tb-O, 2.329(3), 2.399(3), 2.351(3), and 2.367(3) Å). The coordination polyhedron of the Tb(III) atom is a distorted dodecahedron. The photoluminescence and triboluminescence spectra of the [Tb(BTFA)₂(NO₃)(TPPO)₂] complex are identical and caused by the f-f luminescence of Tb³⁺.     

The luminescence of Pr3+ in BaY4Si5O17

The cell constants of four new monoclinic compounds BaR₄X₅O₁₇ (R = Y, Gd; X = Si, Ge) are given. The luminescence of various RE activators in the silicates is reported. Pr³⁺-activated BaY₄Si₅O₁₇ shows efficient ultraviolet 5d → 4f emission and weak 4f → 4f emission (mainly red luminescence from the ¹D₂ level). The 5d → 4f emission is ascribed to Pr³⁺ on Y sites, the 4f → 4f emission to Pr³⁺ on Ba sites. Energy transfer from Pr³⁺ to Gd³⁺ has been observed. Gd³⁺ plays an intermediate role in the energy transfer from Pr³⁺ to Sm³⁺ and to Dy³⁺ in BaGd₄Si₅O₁₇. Upon activation with Tb³⁺ the silicates show characteristic green Tb³⁺ luminescence with a quantum efficiency of 75% for ultraviolet excitation.     

Multibubble sonoluminescence of Tb3+ ion in aqueous solutions of dimethyl sulfoxide

The intensity and spectra of multibubble sonoluminescence of TbCl₃ solutions in water-DMSO mixtures saturated with air and argon are studied. The spectra represent the superposition of the characteristic glow of Tb³⁺ ions and the continuum of emission of electronically excited products of solvent sonolysis (with H₂O*, OH*, and SO₂* as main emitters). Abnormal action of DMSO and sulfur dioxide on the characteristic luminescence of Tb³⁺ ions during sonolysis of aqueous solutions is revealed. These additives enhance the sonoluminescence of water to different extent, quench the sonoluminescence of Tb³⁺, and differently influence the photoluminescence quantum yield of this ion (DMSO acts as activator, whereas SO₂ acts as quencher). Sulfur dioxide quenches the sonoluminescence of Tb3+ much more efficiently than the photoluminescence of Tb³⁺. The abnormal effect of DMSO on sonoluminescence is most probably due to the quenching action of sulfur dioxide formed during sonolysis of DMSO on Tb³⁺* ions in cavitation bubbles.     

Luminescence in NaLn(SO4)2H2O: A host lattice with high-energy vibrations

The luminescence of Ce³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, and Dy³⁺ in NaLn(SO₄)₂H₂O (Ln = lanthanide) is reported. Only Ce³⁺, Gd³⁺, and Tb³⁺ show efficient emission. This is explained in terms of an energy-gap law. Energy transfer is studied in several codoped compositions. The mutual transfer between Gd³⁺ ions is the only one encountered with high probability. The several transfers are discussed and where possible their rates are calculated.     

Synthesis,characterization, and photoluminescence of SrBPO5:R,Na+ (R = Eu3+, Tb3+) phosphor for solid state lighting

A series of phosphors SrBPO₅:R,Na⁺ (R = Eu³⁺, Tb³⁺) were prepared by high-temperature solid-state synthesis, and their phase purity, morphology, IR spectra, and UV-Vis photoluminescence properties were investigated. The f-f transitions of Eu³⁺ and Tb³⁺ ions in the host lattice were assigned and discussed. The excitation and emission spectra indicate that SrBPO₅:Eu³⁺,Na⁺ and SrBPO₅:Tb³⁺,Na⁺ can be effectively excited by ultraviolet (394 and 370 nm), and exhibit reddish orange emission and yellowish green emission, respectively. The influence of the doping concentration on the relative emission intensity of Eu³⁺/Tb³⁺ was investigated, and the critical distance R_c was estimated in term of the concentration quenching data. The present study suggests SrBPO₅:R,Na⁺ (R = Eu³⁺, Tb³⁺) phosphor can be a potential candidate as an UV-convertible phosphor for white light-emitting diodes (LEDs).     

Energy transfer and heat-treatment effect of photoluminescence in Eu-doped TbPO4 nanowires

We have successfully synthesized Eu³⁺-doped TbPO₄ nanowires, which are orderly organized to form bundle-like structure. A thermal treatment up to 600 °C does not modify the size, shape and structure of as-synthesized sample. Due to the energy overlap between Tb³⁺ and Eu³⁺, an efficient energy transfer occurs from Tb³⁺ to Eu³⁺. The effects of Eu³⁺ concentration and thermal treatment on the luminescent properties of Eu³⁺ are investigated. The increase of Eu³⁺ concentration leads to the increase of the energy transfer efficiency from Tb³⁺ to Eu³⁺, but also enhances the probability of the interaction between neighboring Eu³⁺, which results in the concentration quenching. With the heat-treatment, the luminescence of Eu³⁺ presents an obvious increase, but almost no change for the luminescence of Tb³⁺. This difference is explained based on the TGA, DTA, and fluorescent decay dynamics analyses.     

Theoretical study of lanthanide-based in vivo luminescent probes for detecting hydrogen peroxide

The 4f-4f emissions from lanthanide trication (Ln³⁺) complexes are widely used in bioimaging probes. The emission intensity from Ln³⁺ depends on the surroundings, and thus, the design of appropriate photo-antenna ligands is indispensable. In this study, we focus on two probes for detecting hydrogen peroxide, for which emission intensities from Tb³⁺ are enhanced chemo-selectively by the H₂O₂-mediated oxidation of ligands. To understand the mechanism, the Gibbs free energy profiles of the ground and excited states related to emission and quenching are computed by combining our approximation—called the energy shift method—and density functional theory. The different emission intensities are mainly attributed to different activation barriers for excitation energy transfer from the ligand-centered triplet (T1) to the Tb³⁺-centered excited state. Additionally, quenching from T1 to the ground state via intersystem crossing was inhibited by intramolecular hydrogen bonds only in the highly emissive Tb³⁺ complexes. © 2018 Wiley Periodicals, Inc.     

Lifetime studies of the HgNH3 complex

The luminescence induced by the Hg-photosensitized reaction of NH₃ was studied by repetitive fast pulsed excitation. From observations of the decay of the luminescence, the emitter of the 290 nm fluorescence was found to be the precursor of the 340 nm emission (the stabilized complex). The first-order decay rate of the stabilized complex was found to be given by 1/τ_O + k[NH₃], where τ₀ = 2.3 μs and k = 3.5 × 10^?13 cm³ molecule^?1 s^?1.     

Photoluminescence and energy transfer in Tb/Mn co-doped ZnAl2O4 glass ceramics

We report on Tb³⁺ as efficient sensitizer for red photoemission from Mn²⁺-centers in ZnO-B₂O₃-Al₂O₃-Si₂O-Na₂O-SrO glasses and corresponding gahnite glass ceramics. In comparison to singly or co-doped glasses, the glass ceramics exhibit significantly increased emission intensity. Structural considerations, ESR, and dynamic luminescence spectroscopy indicate partial incorporation of Mn²⁺ as well as Tb³⁺ into the crystalline phase, the former on octahedral Zn²⁺-sites. Interionic distance and charge transfer probability between both species depend on crystallization conditions. This enables control of the energy transfer process and, hence, tunability of the color of photoemission by simultaneous emission from Tb³⁺ and Mn²⁺ centers. Concentration quenching in Mn²⁺-singly doped materials was found at a critical dopant concentration of about 1.0 mol%. The energy transfer process was studied in detail by dynamic as well as static luminescence spectroscopy. Spectroscopic results suggest the application of the studied materials as single or dual-mode emitting phosphor for luminescent lighting.     

Nine-coordinate rare earth metal complexes with aminopolycarboxylic acids: Mononuclear (NH4)3[TbIII(ttha)]·5H2O and binuclear (NH4)4[Tb 2 III (dtpa)2]·9H2O

The two title coordination compounds, (NH₄)₃[Tb^III(ttha)]·5H₂O (ttha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid) and (NH₄)₄[Tb ₂ ^III (ttha)]·9H₂O (dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid), have been prepared and characterized by FT-IR, elemental analyses, TG-DTA and single crystal X-ray diffraction techniques. The (NH₄)₃[Tb^III(ttha)]·5H₂O compound is monoclinic, P2₁/c; a = 10.398(1) Å, b = 12.791(1) Å, c = 23.199(2) Å; β = 90.914(2)°; V = 3084.9(5) ų; Z = 4; D _calc = 1.704 g/cm³; μ(MoK _α ) = 2.376 mm^™; R = 0.023 and wR ² = 0.049 for 5429 observed reflections with I ≥ 2σ(I). The [Tb^III(ttha)]³⁻ complex anion in the crystal has a nine-coordinate mononuclear molecular structure with pseudo-monocapped square-antiprismatic configuration. The (NH₄)₄[Tb ₂ ^III (dtpa)₂]·9H₂O compound is triclinic, P-1; a = 9.739(1) Å, b = 10.010(1) Å, c = 12.968(2) Å; α= 85.890(2)°, β = 77.338(2)°, γ = 77.587(2)°; V = 1204.2(2) ų; Z = 1; D _calc = 1.832 g/cm³; μ(MoK _α ) = 3.015 mm^™; R = 0.024 and wR ² = 0.060 for 4750 observed reflections with I ≥ 2σ(I). The [Tb ₂ ^III (dtpa)₂]₄₋ complex anion has a binuclear structure in the crystal; the two Tb^III centers are equivalent and have a nine-coordinate environment with the same pseudo-tricapped trigonal-prismatic configuration. The thermal analysis revealed that the coordination cores of the (NH₄)₃[Tb^III(ttha)]·5H₂O and (NH₄)₄[Tb ₂ ^III (dtpa)₂]·9H₂O compounds are stable up to 221°C and 252°C, respectively. Original Russian Text Copyright ? 2008 by J. Wang, X. Zh. Liu, X. F. Wang, G. R. Gao, Zh. Q. Xing, X. D. Zhang, and R. Xu The text was submitted by the authors in English. Zhurnal Strukturnoi Khimii, Vol. 49, No. 1, pp. 81–89, January–February, 2008.     

Tb3+在MO(M=Ca,Sr)中的长余辉发光

长余辉发光材料的研究与应用，已有近100年的历史，目前仍在许多领域中有着重要应用。此类材料与其他光致发光材料具有相同的发光性能．只是更注重其发光的衰减过程和热释光性能。如．ZnS：Cu作为黄绿色的长余辉发光材料，在1992年以前是余辉性能最好的长余辉发光材料，一直处于发光研究工作的中心。     

Sensitization of Tb3+ luminescence with Ce3+ in LaOBr: Tb3+, Ce3+

Luminescence emission and uv-excitation properties of LaOBr: Tb³⁺, LaOBr: Ce³⁺, and LaOBr: Tb³⁺, Ce³⁺ phosphors were studied. The visible emission spectra of La_0.995Tb_0.005OBr consists of⁵D_3,4 →⁷F_3–6 transitions in the wavelength range of 410–630 nm. The excitation of the Tb³⁺ ion gives a broad 4f → 5d transition band at 254 nm and weaker4f → 4f transition lines above 300 nm. The uv-excitation and emission of La_0.995Ce_0.005OBr at 290, 315, 355 (excitation), and 440 nm (emission) originate from transitions between the 4f-ground state and the four crystal field components of the5d²D excited state. The sensitization of Tb³⁺ luminescence in LaOBr with Ce³⁺ at varying concentrations is described and discussed. With increasing Ce³⁺ concentration the ⁵D₃ →⁷F transitions of Tb³⁺ quench totally and the⁵D₄ →⁷F transitions begin to quench gradually. The excitation spectrum of the⁵D₄ →⁷F₅ transition of Tb³⁺ consists of four bands due to Tb³⁺ and Ce³⁺, of which the three Ce³⁺ bands increase in intensity and the Tb³⁺ band decreases as the Ce³⁺ concentration is increased.     

Preparation,Characterization and Luminescence Study of Chitosan Membrane and Powder Forms with Eu3 + and Tb3 +

Chitosan membranes with trivalent lanthanide ion Eu^{3 +} were prepared at a ratio of 3:1 w/w (chitosan:lanthanide). There was no membrane formation at a ratio of 1:1 w/w (chitosan: Eu^{3 +} or Tb^{3 +}); in this case a white solid powder was obtained. Both chitosan compounds were characterized by elemental analysis (CHN), thermal analysis (TG/DTG), scanning electron microscopy (SEM) and luminescence spectroscopy. CHN analysis was performed only for chitosan compounds in powder form, suggesting that these compounds have the general formula QUILn.6H₂O, where QUI = Chitosan and Ln = Eu^{3 +} or Tb^{3 +}. The results of TG/DTG curves for chitosan membranes with Eu^{3 +} ion indicate that the introduction of this metal into the chitosan structure causes gradual degradation in residual carbons, showing lower weight loss in the Eu^{3 +} membranes compared to pure chitosan membrane. Analysis of luminescence demonstrated that chitosan membranes with Eu^{3 +} ion exhibit emission in the visible region, showing emission bands from chitosan and Eu^{3 +} moieties. For chitosan with Eu^{3 +} and Tb^{3 +} ions compounds, in powder form, the analysis of luminescence suggested that chitosan is not transferring energy to the lanthanide ion; however, the chemical region where the lanthanide ion is found breaks the selection rules and favors the emission of these ions.     

Spectroscopic studies on the interaction of cilostazole with iodine and 2,3-dichloro-5,6-dicyanobenzoquinone

Lanthanide sensitized luminescence and chemiluminescence (CL) are of great importance because of the unique spectral properties, such as long lifetime, large Stokes shifts, and narrow emission bands characteristic to lanthanide ions (Ln³⁺). With the fluoroquinolone (FQ) compounds including enoxacin (ENX), norfloxacin (NFLX), lomefloxacin (LMFX), fleroxacin (FLRX), ofloxacin (OFLX), rufloxacin (RFX), gatifloxacin (GFLX) and sparfloxacin (SPFX), the luminescence and CL properties of Tb³⁺–FQ and Eu³⁺–FQ complexes have been investigated in this contribution. Ce⁴⁺–SO₃²⁻ in acidic conditions was taken as the CL system and sensitized CL intensities of Tb³⁺–FQ and Eu³⁺–FQ complexes were determined by flow-injection analysis. The luminescence and CL spectra of Tb³⁺–FQ complexes show characteristic peaks of Tb³⁺ at 490 nm, 545 nm, 585 nm and 620 nm. Complexes of Tb³⁺–ENX, Tb³⁺–NFLX, Tb³⁺–LMFX and Tb³⁺–FLRX display relatively strong emission intensity compared with Tb³⁺–OFLX, Tb³⁺–RFX, Tb³⁺–GFLX and Tb³⁺–SPFX. Quite weak peaks with unique characters of Eu³⁺ at 590 nm and 617 nm appear in the luminescence and CL spectra of Eu³⁺–ENX, but no notable sensitized luminescence and CL of Eu³⁺ could be observed when Eu³⁺ is added into other FQ. The distinct differences on emission intensity of Tb³⁺–FQ and Eu³⁺–FQ might originate from the different energy gap between the triplet levels of FQ and the excited levels of the Ln³⁺. The different sensitized luminescence and CL signals among Tb³⁺–FQ complexes could be attributed to different optical properties and substituents of these FQ compounds. The detailed mechanism involved in the luminescence and CL properties of Tb³⁺–FQ and Eu³⁺–FQ complexes has been investigated by analyzing the luminescence and CL spectra, quantum yields, and theoretical calculation results.