English

• Chemiluminescence (CL) accompanying with light emission by the chemical reaction, displays the merits of high sensitivity, wide linear range and low background signal. It has been widespreadly used in food analysis [1,2], environmental monitoring [3,4] and chem-/biosensing [5], etc. The common CL systems include luminol [6,7], peroxyoxalate [8-10], potassium permanganate [11,12], cerium [13,14], periodate [15,16], etc. However, most of these CL systems are based on the emission of molecular luminophore. The broad emission band of molecular luminophore makes multi-component analysis be difficult. Hence, developing a new CL system that can achieve multiple components is still highly desired.

  In recent years, rare earth elements (REEs) have attracted widespread interest owing to their unique properties. The photoluminescence properties of lanthanide ions (Ln³⁺) mostly come from the f→f transitions of its 4f orbitals, which are well shielded from the environment by the outer 5s² and 5p⁶ shells. Importantly, the Ln³⁺ ions are usually characterized by narrow band emission, large Stokes shifts and long luminescence lifetime [17-19]. Thus, the narrow band emission of Ln³⁺ ions makes it promising for multi-component analysis. In most cases, the Ln³⁺ excitation was achieved by light source [20-22]. The background of the light sources can usually deteriorate the sensing sensitivity.

  Recently, chemoexitation has demonstrated to be promising for the excitation of fluorophore [23,24], quantum dots [25], etc., since CL excitation can avoid light background and improve the signal-to-noise ratio during detection [2]. In recent years, REE ions especially Tb³⁺ and Eu³⁺ were also successfully chemoexcited by reaction system such as oxalate-hydrogen peroxide (H₂O₂), SO₃²⁻-Eu/CeO₂, periodate (IO₄⁻)-H₂O₂ [26-29]. Among them, IO₄⁻ was the mostly used as the oxidant since it is water-soluble and colourless which evades the emission absorption problems [30,31]. Nevertheless, the simultaneous extation of Tb³⁺ and Eu³⁺ by the CL reaction system has not been studied. Additionaly, the relatively weak CL emission from Tb³⁺/Eu³⁺-based CL systems limits their applications in chemo/bio-sensing.

  Hence, in this work, we demonstrate the simultaneous excitation of Tb³⁺ and Eu³⁺ by IO₄⁻-H₂O₂ CL reaction, and the analytical procedure is shown in Fig. S1 (Supporting information). The reactive oxygen species (ROSs) especically singlet oxygen (¹O₂) that generated by IO₄⁻-H₂O₂ system can transfer its energy to the complex of Tb³⁺/Eu³⁺-ethylenediaminetetraacetic acid disodium salt (EDTA), then producing the CL emissions of Tb³⁺ and Eu³⁺. More importantly, the emissions can be further enhanced by the catalysis of gold nanoparticles (AuNPs). The resulted strong characteristic CL emissions of Tb³⁺ at 490 nm and Eu³⁺ at 620 nm allow sensitive and simultaneous detection of Tb³⁺ and Eu³⁺. This AuNPs-catalyzed rare earth complexes CL system provides a new CL technique for multiplex sensing with simplicity and high sensitivity.

  As shown in Fig. 1A, Tb³⁺ cannot yield CL emission in the presence of NaIO₄, H₂O₂ or EDTA alone, and even in the CL reaction between NaIO₄ and H₂O₂; the characteristic CL emissions of Tb³⁺ appear only in the presence of NaIO₄, H₂O₂ and EDTA. It indicates that EDTA plays an important role in the luminescence of Tb³⁺, which can be attributed to the antenna effect of ligands [32,33].

  Figure 1

  

  Figure 1.  (A) Sensitization CL of Tb³⁺. (B) CL of various rare earth ions. (C) CL of different ligands in Tb³⁺ and Eu³⁺ system. Experimental conditions: NaIO₄, 24 mmol/L; H₂O₂, 18 mmol/L; EDTA, 35 mmol/L; all the ion are 5 mmol/L in (A and B), except for Tb³⁺, 1 mmol/L. In (C), NaIO₄, 8–18 mmol/L; H₂O₂, 10.67–48 mmol/L; Tb³⁺, 1 µmol/L; ligands, 0.2–13 mmol/L in Tb³⁺; NaIO₄, 10–16 mmol/L; H₂O₂, 8–30 mmol/L; Eu³⁺, 20 µmol/L; ligands, 0.2–6.67 mmol/L in Eu³⁺.

  DownLoad: Full-Size Img PowerPoint

  Luminescence is an important property of rare earth ions, so we further verify whether other rare earth ions could also produce CL in this investigated system. The investigated ions include La³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Dy³⁺, Er³⁺, Eu³⁺ and Gd³⁺. It can be seen in Fig. 1B, only Tb³⁺, Eu³⁺ and Dy³⁺ produce obvious CL emissions with Tb³⁺ being the strongest, Eu³⁺ the second strongest and Dy³⁺ the smallest. This may be attributed to the difference in energy transfer efficiency between EDTA and these investigated ions, because only Tb³⁺, Eu³⁺ and Dy³⁺ also produce characteristic emissions in the fluorescence experiments (Fig. S2 in Supporting information). Although the emission peaks of Tb³⁺ and Dy³⁺ overlap at 490 nm, the intensity of 1 mmol/L Tb³⁺ is much higher than that of 5 mmol/L Dy³⁺. Since the high CL eimissions of Tb³⁺ and Eu³⁺-EDTA complexes, so we use the CL system for multiplex detection of Tb³⁺ and Eu³⁺.

  The results in Fig. 1A show that ligand is critically important for the CL process of Tb³⁺. Therefore, we studied the sensitisation role of a variety of ligands in Tb³⁺ and Eu³⁺ CL emissions, including EDTA, 2′-deoxyadenosine 5′-triphosphate trisodium salt (ATP), diethylenetriamine-pentaacetic acid (DTPA), sulfosalicylic acid dehydrate (SAD), l-cysteine hydrochloride monohydrate (Cys), 2, 6-pyridinedicarboxylic acid (DPA) and enrofloxacin (ENX). As depicted in Fig. 1C, the three ligands (EDTA, ATP and DTPA) can produce strong CL emissions from the NaIO₄-H₂O₂-Tb³⁺/Eu³⁺ systems under their optimal conditions, the CL curves of Tb³⁺ and Eu³⁺ with a variety of ligands were shown in Fig. S3 (Supporting information). And EDTA was selected for subsequent experiments by considering the stability of the complexes as well as the cost effectiveness.

  In recent years, the enhancement of CL by the catalysis of Au NPs has been studied [34-36], hence we also intend to explore whether AuNPs can contribute to the CL emissions of Tb³⁺ and Eu³⁺. The synthetic AuNPs were characterized by transmission electron microscopy (TEM), ultravioletvisible (UV–vis) spectrophotometer and X-ray Photoelectron Spectroscopy (XPS). The data in Fig. 2A revealed that they are spherical particles with an average diameter of about 13 nm and the UV absorption peak at 520 nm was illustrated in Fig. S4 (Supporting information). The overall XPS survey shows the presence of strong C 1s, O 1s and Au 4f core levels of citrate capped AuNPs (Fig. S5 in Supporting information). In Fig. 2B, we found that the presence of AuNPs in the NaIO₄-H₂O₂-EDTA-Tb³⁺ solution caused an obvious enhancement in the CL emission. And AuNPs also has a catalysis effect on Eu³⁺ CL emission (Fig. S6 in Supporting information).

  Figure 2

  

  Figure 2.  (A) TEM of synthetic AuNPs. (B) The effect of AuNPs on the reaction of NaIO₄-H₂O₂-EDTA-Tb³⁺. (C) DMPO/^•OH adduct in NaIO₄-H₂O₂ system in the absence or presence of AuNPs. (D) DMPO/^•O₂^- adduct in NaIO₄-H₂O₂ system in the absence or presence of AuNPs. (E) DMPO/¹O₂ adduct in NaIO₄-H₂O₂ system in the absence or presence of AuNPs. (F) DPBF detection of ¹O₂ in presence of AuNPs. Experimental conditions: TbCl₃, 1 mmol/L; EDTA, 35 mmol/L; H₂O₂, 18 mmol/L; NaIO₄, 24 mmol/L; AuNPs, 2 nmol/L and DPBF, 200 µmol/L.

  DownLoad: Full-Size Img PowerPoint

  The reaction of IO₄⁻ with H₂O₂ may involve the generation of ROSs, such as hydroxyl radicals (^•OH) and superoxide anion (^•O₂⁻) [31,37,38] which are important for the CL. This was confirmed by free radical scavenging experiments (Fig. S7 in Supporting information) and room temperature electron paramagnetic resonance (EPR) analysis (Figs. 2C-E), which indicated that three free radicals (^•OH, ^•O₂⁻ and ¹O₂) are indeed generated in the NaIO₄-H₂O₂ system. Furthermore, it found that the addition of AuNPs to the NaIO₄-H₂O₂ system resulted in significantly increasing signals for 2, 2, 6, 6-tetramethylpiperidinooxy (TEMPO) adduct (Fig. 2E), suggesting that AuNPs could promote the production of ¹O₂. It is generally believed that oxidation of H₂O₂ by IO₄⁻ generates excited singlet oxygen molecular pair [(¹O₂)₂*], which then produces a CL emission [31,39]. So we have further explored the effect of AuNPs on the production of ¹O₂ using 1, 3-diphenylisobenzofuran (DPBF) as an indicator. From Fig. 2F, it can be concluded that AuNPs indeed contribute to the production of ¹O₂ because UV absorption of DPBF is reduced more seriously in the presence of AuNPs. These results indicated the good catalytic activity of AuNPs for enhanced generation of ¹O₂ in the investigated CL system.

  For the catalytic effect of AuNPs, it is generally believed that the O−O bond of H₂O₂ might be broken up into double ^•OH radicals and these radicals were further stabilized by AuNPs via partial electron exchange interactions [40]. And the generated ^•OH reacted with H₂O₂ to facilitate the formation of HO₂^•, which immediately dissociated into ^•O₂⁻ at high pH values [41]. Additionally, ^•OH and ^•O₂⁻ radicals could also be generated from the reaction of IO₄⁻ with dissolved O₂. ¹O₂ could be produced from the reaction of H₂O₂ or ROSs (e.g. ^•O₂⁻ or ^•OH) with IO₄⁻ [42].

  It has been reported that ¹O₂ can transfer its energy to fluorescent substances by the intermolecular energy transfer process [43,44]. However, lanthanide 4f^N–4f^N transitions are Laporte forbidden, and the direct excitation of electrons in tripositive lanthanide ions is inefficient. Hence, a sensitizing chromophore is usually used as a ligand to chelate to the emissive lanthanide center [18,19]. In such case, the rare earth ion can be excited by the antenna effect. So in this work, the fluorescence quantum yield of Tb³⁺ is greatly enhanced through an intramolecular energy transfer when it forms complexes with EDTA (Fig. 1A).

  Hence, the AuNPs-catalzyed CL mechanism of the rare earth complex can be concluded as in Fig. 3: (i) AuNPs catalyzed the production of ¹O₂ from NaIO₄-H₂O₂ system; (ii) the generated ¹O₂ transfered its energy to the ligand (i.e., EDTA) to reach the excited state via intermolecular energy transfer effect and (iii) the rare earth ion was excited via the antenna effect from ligand, being followed by ⁵D₄ emission of Tb³⁺ in the [Tb(EDTA)]⁻ complex (Fig. 1C). The catalytic activity of AuNPs was quite stable with a decline about 5.3% in a week.

  Figure 3

  

  Figure 3.  Possible chemiluminescence reaction mechanism. (A) Reaction bwtween NaIO₄ and H₂O₂ to produce ROSs, (B) intermolecular energy transfer processes between ¹O₂ and rare earth complexes, and (C) Antenna effect between ligands and rare earth ions.

  DownLoad: Full-Size Img PowerPoint

  We verified the feasibility of simultaneous detection of Tb³⁺ and Eu³⁺ by the constructed CL systems. The characteristic peaks of Tb³⁺ and Eu³⁺ are mainly at 490 nm and 540 nm, 595 nm and 610 nm (Fig. 4A), respectively. And Dy³⁺ in concentrations equal to Tb³⁺ (0.5 mmol/L) produces nearly no luminescence. More importantly, these characteristic peaks (490 nm for Tb³⁺ and 610 nm for Eu³⁺) do not mutually interfere in the mixed CL system of NaIO₄-H₂O₂-Tb³⁺-Eu³⁺-EDTA. Hence, the CL system enables multiplex detection of Tb³⁺ and Eu³⁺.

  Figure 4

  

  Figure 4.  (A) Construction of a multi-component luminescent system. (B) The standard curves and detection limits of Tb³⁺. (C) The standard curves and detection limits of Eu³⁺. Experimental conditions: (A) Tb³⁺, 0.5 mmol/L; Dy³⁺, 0.5 mmol/L; Eu³⁺, 4 mmol/L; EDTA, 35 mmol/L; H₂O₂, 18 mmol/L and NaIO₄, 24 mmol/L. (B) EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L and 480 nm filter. (C) EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L and 620 nm filter.

  DownLoad: Full-Size Img PowerPoint

  Some parameters that affect the CL emission were examined, including the concentrations of CL reagents and the pH of solutions (Figs. S8–S12 in Supporting information). Under optimal conditions, the linear response range of NaIO₄-H₂O₂-EDTA-AuNPs for Tb³⁺ and Eu³⁺ were depicted in Figs. 4B and C. It revealed that the CL intensity of NaIO₄-H₂O₂-EDTA-AuNPs was gradually enhanced with the increase of the Tb³⁺ concentration, and the linear response is ranging from 2.0 × 10⁻⁸ mol/L to 1.0 × 10⁻⁶ mol/L (R² = 0.9941). And the CL intensity is also enhanced linearly with increasing Eu³⁺ concentration in the range of 1.0 × 10⁻⁶ mol/L to 5.0 × 10⁻⁵ mol/L (R² = 0.9967). The limits of detection (LOD) were calculated to be 5.0 × 10⁻⁹ mol/L and 8.0 × 10⁻⁷ mol/L for Tb³⁺ and Eu³⁺ respectively (3σ). Notably, the NaIO₄-H₂O₂-EDTA-AuNPs CL system is much more sensitive than the corresponding fluorescence detection shown in Fig. S13 (Supporting information), in which the LODs for Tb³⁺ and Eu³⁺ were 6.7 × 10⁻⁶ mol/L and 2.1 × 10⁻⁵ mol/L, respectively. The results of comparing with other methods for the detection of Tb³⁺ and Eu³⁺ are summarized in Table S1 (Supporting information). These results showed that the NaIO₄-H₂O₂-EDTA-AuNPs system had good linearity, high sensitivity and reproducibility.

  To estimate the selectivity of the sensing system, we measured a variety of potentially interfering metal ions on the effect of the system, including Sm³⁺, Dy³⁺, Gd³⁺, Ce³⁺, Nd³⁺, La³⁺, Fe³⁺, Al³⁺, Zn²⁺, Ni²⁺, Co²⁺, Mg²⁺ and Cu²⁺. Fig. S14 (Supporting information) demonstrated that only Tb³⁺ and Eu³⁺ can produce strong CL emission, negligible CL intensities were observed for other metal ions at the same concentrations. And the typical metal ions were further used to investigate the anti-interference ability of the system. As shown in Figs. 5A and B, the CL signals for 0.5 µmol/L Tb³⁺ and 20 µmol/L Eu³⁺ were affected weakly by the examined ions. And for the determination of Tb³⁺, the tolerable concentration ratios for interference at the 10% level were over 1000 for K⁺, Na⁺ and NH₄⁺; 200 for La³⁺, 100 for Al³⁺ and Gd³⁺, 50 for Ce³⁺ and Eu³⁺, 10 for Mg²⁺, Fe³⁺, Ni²⁺, Cu²⁺ and Sm³⁺, 5 for Co²⁺ and Dy³⁺. With respect to Eu³⁺, the tolerable limit could reach more than 330 times for K⁺, Na⁺ and NH₄⁺, 20 for Mg²⁺, La³⁺, 13 for Al³⁺, 6 for Ni²⁺, Fe³⁺, Ce³⁺ and Gd³⁺, 3 for Co²⁺, Cu²⁺ and Dy³⁺. And the same concentration of Sm³⁺ and Tb³⁺ has no effect on CL of Eu³⁺. Hence, the CL system has good selectivity and anti-interference ability.

  Figure 5

  

  Figure 5.  Anti interference experiment. (A) NaIO₄-H₂O₂-EDTA-Tb³⁺. (B) NaIO₄-H₂O₂-EDTA-Eu³⁺. Experimental conditions: EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L; Tb³⁺, 0.5 µmol/L, interference ions, 0.5–33 µmol/L and 480 nm filter in (A). EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L; Eu³⁺, 20 µmol/L, interference ions, 20–3000 µmol/L, 620 nm filter in (B).

  DownLoad: Full-Size Img PowerPoint

  The applicability for real sample analysis was verified by determination of Tb³⁺ and Eu³⁺ in leaching solution of mine sample. Also, the Tb³⁺ and Eu³⁺ contents in Metal-organic frameworks (MOFs) materials were assessed by this sensing system. In Table 1, the measured values of Tb³⁺ and Eu³⁺ in the samples were in good agreement with those obtained by inductively coupled plasma mass spectrometry (ICP-MS). Hence, the system was practical for real sample analysis.

  Table 1

  

  Table 1.  Determination of Tb³⁺ and Eu³⁺ in samples.

  DownLoad: CSV

  In summary, rare earth complexes CL system that can catalyzed by AuNPs was developed for fast sensing of Tb³⁺ and Eu³⁺. The ¹O₂ generated from NaIO₄-H₂O₂ system can transfer its energy to the complex of Tb³⁺/Eu³⁺-EDTA complex, following by the characteristic emissions of Tb³⁺ and Eu³⁺. The AuNPs can act as a catalyst for boosting the generation of ¹O₂ in NaIO₄-H₂O₂ system. Thanking to their narrow band emission of rare earth ions, simultaneous determination of Tb³⁺ and Eu³⁺ can be easily achieved at 490 nm and 620 nm, respectively. This sensing system with the merits of high sensitivity, selectivity as well as simplicity for the determination of Tb³⁺ and Eu³⁺, provides a new avenue for multi-component CL analysis.

  Declaration of competing interest

  The authors declare no conflict of interest.

  Acknowledgments

  The authors gratefully acknowledge the financial support from the Sichuan Science and Technology Project (No. 2022NSFSC1087) and the Project of State Key Laboratory of Supramolecular Structure and Materials (No. sklssm2022034).

  Supplementary materials

  Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.cclet.2023.108155.

  
  
• 1. [1]

     B. Li, Y. He, Luminescence 22 (2007) 317–325. doi: 10.1002/bio.965

  2. [2]

     M. Liu, Z. Lin, J.M. Lin, Anal. Chim. Acta 670 (2010) 1–10. doi: 10.1016/j.aca.2010.04.039

  3. [3]

     L. Li, T. Yang, J. Yang, X. Zhang, Sens. Actuator B Chem. 353 (2022) 131038. doi: 10.1016/j.snb.2021.131038

  4. [4]

     S.N.A. Shah, X. Dou, M. Khan, K. Uchiyama, J.M. Lin, Talanta 196 (2019) 370–375. doi: 10.1016/j.talanta.2018.12.091

  5. [5]

     Y. Sun, J. Lu, Luminescence 33 (2018) 1298–1305. doi: 10.1002/bio.3557

  6. [6]

     C. Wang, M.I. Halawa, B. Lou, et al., Analyst 146 (2021) 1981–1985. doi: 10.1039/d0an02280b

  7. [7]

     Z. Li, Y. Xi, A. Zhao, et al., Anal. Bioanal. Chem. 413 (2021) 3541–3550. doi: 10.1007/s00216-021-03305-8

  8. [8]

     C. Zhang, J. Jin, K. Liu, X. Ma, X. Zhang, Chin. Chem. Lett. 32 (2021) 3931–3935. doi: 10.3390/su13073931

  9. [9]

     L. Li, D. Lin, F. Yang, et al., ACS Appl. Nano Mater. 4 (2021) 3932–3939. doi: 10.1021/acsanm.1c00305

  10. [10]

      W. Fan, L. Li, J. Yuan, et al., Anal. Chem. 93 (2021) 17043–17050. doi: 10.1021/acs.analchem.1c03798

  11. [11]

      J. Du, W. Liu, J. Lu, Luminescence 18 (2003) 341–345. doi: 10.1002/bio.746

  12. [12]

      Q. Hu, S. Chen, F. Chen, Spectroc. Acta Part. A-Molec. Biomolec. Spectr. 264 (2022) 120332. doi: 10.1016/j.saa.2021.120332

  13. [13]

      C. Pang, S. Han, Y. Li, J. Zhang, J. Chin. Chem. Soc. 65 (2018) 1504–1509. doi: 10.1002/jccs.201800141

  14. [14]

      C. Zhu, L. Wei, P. Yuan, L. Xiong, X. Cheng, Instrum. Sci. Technol. 45 (2016) 219–231. doi: 10.1007/978-3-319-31676-5_16

  15. [15]

      Y. Li, Y.Z. Zheng, D.K. Zhang, et al., Chin. Chem. Lett. 28 (2017) 184–188. doi: 10.1016/j.cclet.2016.07.020

  16. [16]

      S.N.A. Shah, A.H. Shah, X. Dou, et al., ACS Omega 4 (2019) 15004–15011. doi: 10.1021/acsomega.9b01785

  17. [17]

      P. Escribano, B. Julián-López, J. Planelles-Aragó, et al., J. Mater. Chem. 18 (2008) 23–40. doi: 10.1039/B710800A

  18. [18]

      L.D. Carlos, R.A.S. Ferreira, V. d. Z. Bermudez, S.J.L. Ribeiro, Adv. Mater. 21 (2009) 509–534. doi: 10.1002/adma.200801635

  19. [19]

      K. Binnemans, Chem. Rev. 109 (2009) 4283–4374. doi: 10.1021/cr8003983

  20. [20]

      X. Chen, Y. Xu, H. Li, Dyes Pigment. 178 (2020) 108386. doi: 10.1016/j.dyepig.2020.108386

  21. [21]

      Y. Su, J. Yu, Y. Li, et al., Commun. Chem. 1 (2018) 1–13. doi: 10.1038/s42004-018-0011-5

  22. [22]

      X. Zhou, T. Wang, M. Zhao, et al., Sens. Actuator B Chem. 343 (2021) 130107. doi: 10.1016/j.snb.2021.130107

  23. [23]

      H. Chen, W. Xue, C. Lu, et al., Spectroc. Acta Part. A-Molec. Biomolec. Spectr. 116 (2013) 355–360. doi: 10.1016/j.saa.2013.07.057

  24. [24]

      S. Cai, Y. Zhou, J. Ye, et al., Microchim. Acta 186 (2019) 463–475. doi: 10.1007/s00604-019-3509-3

  25. [25]

      H. Song, Y. Su, L. Zhang, Y. Lv, Luminescence 34 (2019) 530–543. doi: 10.1002/bio.3633

  26. [26]

      H. Li, Y. Sun, Y. Li, J. Du, Microchem J. 160 (2021) 105665. doi: 10.1016/j.microc.2020.105665

  27. [27]

      Q. Li, M. Sun, Y. Su, K. Zhang, Y. Lv, Sens. Actuator B Chem. 339 (2021) 129876. doi: 10.1016/j.snb.2021.129876

  28. [28]

      X. Wang, H. Zhao, X. Li, S. Chen, Chin. J. Anal. Chem. 33 (2005) 647–649.

  29. [29]

      S. Chen, H. Zhao, X. Wang, X. Li, L. Jin, Anal. Chim. Acta 506 (2004) 25–29. doi: 10.1016/j.aca.2003.11.040

  30. [30]

      Y. Li, J. Wang, Y. Yang, S. Han, Luminescence 35 (2020) 773–780. doi: 10.1002/bio.3783

  31. [31]

      S.N. Shah, H. Li, J.M. Lin, Talanta 153 (2016) 23–30. doi: 10.1016/j.talanta.2016.02.056

  32. [32]

      N. Sabbatini, M. Guardigli, J.M. Lehn, Coord. Chem. Rev. 123 (1993) 201–228. doi: 10.1016/0010-8545(93)85056-A

  33. [33]

      G.F. de Sá, O.L. Malta, C. de Mello Donegá, et al., Coord. Chem. Rev. 196 (2000) 165–195. doi: 10.1016/S0010-8545(99)00054-5

  34. [34]

      Z.F. Zhang, H. Cui, C.Z. Lai, L.J. Liu, Anal. Chem. 77 (2005) 3324–3329. doi: 10.1021/ac050036f

  35. [35]

      S. Cai, K. Lao, C. Lau, J. Lu, Anal. Chem. 83 (2011) 9702–9708. doi: 10.1021/ac202789q

  36. [36]

      Y. Qi, B. Li, Spectroc. Acta Part. A-Molec. Biomolec. Spectr. 111 (2013) 1–6. doi: 10.1109/VCIP.2013.6706384

  37. [37]

      C. Huang, Y. Wang, Y. Wang, et al., Appl. Surf. Sci. 579 (2022) 151860. doi: 10.1016/j.apsusc.2021.151860

  38. [38]

      J. Liu, H. Chen, L. Lin, C. Lu, J. Lin, Chin. Sci. Bull. 55 (2010) 3479–3484. doi: 10.1007/s11434-010-4059-6

  39. [39]

      M. Zhang, D. Han, C. Lu, J.M. Lin, J. Phys. Chem. C 116 (2012) 6371–6375. doi: 10.1021/jp300879c

  40. [40]

      Z. Zhang, A. Berg, H. Levanon, R.W. Fessenden, D. Meisel, J. Am. Chem. Soc. 125 (2003) 7959–7963. doi: 10.1021/ja034830z

  41. [41]

      J. Rabani, S.O. Nielsen, J. Am. Chem. Soc. 73 (2002) 3736–3744.

  42. [42]

      T.Y. Huang, W.Y. Lin, Luminescence 26 (2011) 118–124. doi: 10.1002/bio.1193

  43. [43]

      J. Liu, H. Chen, Z. Lin, J.M. Lin, Anal. Chem. 82 (2010) 7380–7386. doi: 10.1021/ac101510b

  44. [44]

      Y. Zheng, D. Zhang, S.N.A. Shah, H. Li, J.M. Lin, Chem. Commun. 53 (2017) 5657–5660. doi: 10.1039/C7CC02041D

• 

  Figure 1  (A) Sensitization CL of Tb³⁺. (B) CL of various rare earth ions. (C) CL of different ligands in Tb³⁺ and Eu³⁺ system. Experimental conditions: NaIO₄, 24 mmol/L; H₂O₂, 18 mmol/L; EDTA, 35 mmol/L; all the ion are 5 mmol/L in (A and B), except for Tb³⁺, 1 mmol/L. In (C), NaIO₄, 8–18 mmol/L; H₂O₂, 10.67–48 mmol/L; Tb³⁺, 1 µmol/L; ligands, 0.2–13 mmol/L in Tb³⁺; NaIO₄, 10–16 mmol/L; H₂O₂, 8–30 mmol/L; Eu³⁺, 20 µmol/L; ligands, 0.2–6.67 mmol/L in Eu³⁺.

  下载: 全尺寸图片 幻灯片
  

  Figure 2  (A) TEM of synthetic AuNPs. (B) The effect of AuNPs on the reaction of NaIO₄-H₂O₂-EDTA-Tb³⁺. (C) DMPO/^•OH adduct in NaIO₄-H₂O₂ system in the absence or presence of AuNPs. (D) DMPO/^•O₂^- adduct in NaIO₄-H₂O₂ system in the absence or presence of AuNPs. (E) DMPO/¹O₂ adduct in NaIO₄-H₂O₂ system in the absence or presence of AuNPs. (F) DPBF detection of ¹O₂ in presence of AuNPs. Experimental conditions: TbCl₃, 1 mmol/L; EDTA, 35 mmol/L; H₂O₂, 18 mmol/L; NaIO₄, 24 mmol/L; AuNPs, 2 nmol/L and DPBF, 200 µmol/L.

  下载: 全尺寸图片 幻灯片
  

  Figure 3  Possible chemiluminescence reaction mechanism. (A) Reaction bwtween NaIO₄ and H₂O₂ to produce ROSs, (B) intermolecular energy transfer processes between ¹O₂ and rare earth complexes, and (C) Antenna effect between ligands and rare earth ions.

  下载: 全尺寸图片 幻灯片
  

  Figure 4  (A) Construction of a multi-component luminescent system. (B) The standard curves and detection limits of Tb³⁺. (C) The standard curves and detection limits of Eu³⁺. Experimental conditions: (A) Tb³⁺, 0.5 mmol/L; Dy³⁺, 0.5 mmol/L; Eu³⁺, 4 mmol/L; EDTA, 35 mmol/L; H₂O₂, 18 mmol/L and NaIO₄, 24 mmol/L. (B) EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L and 480 nm filter. (C) EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L and 620 nm filter.

  下载: 全尺寸图片 幻灯片
  

  Figure 5  Anti interference experiment. (A) NaIO₄-H₂O₂-EDTA-Tb³⁺. (B) NaIO₄-H₂O₂-EDTA-Eu³⁺. Experimental conditions: EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L; Tb³⁺, 0.5 µmol/L, interference ions, 0.5–33 µmol/L and 480 nm filter in (A). EDTA, 13 mmol/L; H₂O₂, 10.67 mmol/L; NaIO₄, 13 mmol/L; AuNPs, 2 nmol/L; Eu³⁺, 20 µmol/L, interference ions, 20–3000 µmol/L, 620 nm filter in (B).

  下载: 全尺寸图片 幻灯片

  Table 1.  Determination of Tb³⁺ and Eu³⁺ in samples.

  下载: 导出CSV
•