A New Highly Selective Colorimetric and Fluorometric Coumarin-based Chemosensor for Hg2+


A novel colorimetric and fluorometric method based on coumarin as signalling unit was developed for Hg2+ recognition and quantification. Initially, the alkyne functionality was incorporated into a coumarin system and the resulting molecule showed higher specificity and sensitivity for Hg2+ over other cations in both absorption and emission sensing assays. The Hg2+ recognition was detected as visible colour change from colourless to yellow and as fluorescence quenching. The colour change was assigned to the increased intramolecular charge transfer (ICT) in the signalling unit upon Hg2+ binding whereas a decline in the fluorescence intensity was ascribed to the heavy atom effect from Hg2+. In order to generate a material with high sensing performance level, alkyne-functionalized molecule was hosted into a polymeric material. The resulting functionalized polymer showed higher sensitivity and selectivity for Hg2+ over its corresponding coumarin molecule. The investigation of the possible binding modes for Hg2+ suggested both alkyne and triazole functionalities as potential binding sites for Hg2+. The limit of detection (LOD) and limit of quantification (LOQ) of the proposed method were evaluated and values less than a recommended maximum level of Hg2+contaminant in drinking water (2.00 μg/L) were obtained (LOD = 0.44 μg/L and LOQ = 1.33μg/L). The real-life application of the method was investigated using natural water samples containing Hg2+ levels equivalent to the maximum tolerable concentration of Hg2+ in drinking water. The outcomes suggested that the method could be used in the sensing and determination of Hg2+ level of contaminant in the environment.

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  1. 1.

    Pacyna EG, Pacyna JM (2002) Global emission of mercury from anthropogenic sources in 1995. Water Air Soil Pollut 137:149–165

  2. 2.

    Lee JS, Han MS, Mirkin CA (2007) Colorimetric detection of mercuric ion (Hg2+) in aqueous media using DNA‐functionalized gold nanoparticles. Angew Chem Int Ed 46:4093–4096

  3. 3.

    Onyido I, Norris AR, Buncel E (2004) Biomolecule-mercury interactions: Modalities of DNA base-mercury binding mechanisms. remediation strategies. Chem Rev 104:5911–5930

  4. 4.

    Harris HH, Pickering IJ, George GN (2003) The chemical form of mercury in fish. Science 301:1203–1203

  5. 5.

    Yoon S, Albers AE, Wong AP, Chang CJ (2005) Screening mercury levels in fish with a selective fluorescent chemosensor. J Am Chem Soc 127:16030–16031

  6. 6.

    Nolan EM, Lippard SJ (2008) Tools and tactics for the optical detection of mercuric ion. Chem Rev 108:3443–3480

  7. 7.

    Zahir F, Rizwi SJ, Haq SK, Khan RH (2005) Low dose mercury toxicity and human health. Environ Toxicol Pharmacol 20:351–360

  8. 8.

    Li P, Feng X, Qiu G (2010) Methylmercury exposure and health effects from rice and fish consumption: a review. Int. J Environ Res Public Health 7:2666–2691

  9. 9.

    Khdary NH, Howard AG (2011) New solid-phase-nanoscavenger for the analytical enrichment of mercury from water. Analyst 136:3004–3009

  10. 10.

    Chandio ZA, Talpur FN, Khan H, Afridi HI, Khaskheli GQ, Mughal MA (2014) On-line preconcentration and determination of ultra trace amounts of mercury using surfactant coated alumina modified by dithizone with cold vapor atomic absorption spectrometry. RSC Adv 4:3326–3331

  11. 11.

    Gao Z, Ma X (2011) Speciation analysis of mercury in water samples using dispersive liquid–liquid microextraction combined with high-performance liquid chromatography. Anal Chim Acta 702:50–55

  12. 12.

    Gao Y, Shi Z, Long Z, Wu P, Zhen C, Hou X (2012) Determination and speciation of mercury in environmental and biological samples by analytical atomic spectrometry. Microchem J 103:1–14

  13. 13.

    Leopold K, Foulkes M, Worsfold P (2010)  Methods for the determination and speciation of mercury in natural waters—a review. Anal Chim Acta 663:127–138

  14. 14.

    Zhang Z, Li J, Song X, Ma J, Chen L (2014)  Hg2+ ion-imprinted polymers sorbents based on dithizone–Hg2+ chelation for mercury speciation analysis in environmental and biological samples. RSC Adv 4:46444–46453

  15. 15.

    Yordanova T, Vasileva P, Karadjovaand I, Nihtianova D (2014) Submicron silica spheres decorated with silver nanoparticles as a new effective sorbent for inorganic mercury in surface waters. Analyst 139:1532–1540

  16. 16.

    Ma S, Chen Q, Li H, Wang P, Islam SM, Gu Q, Yang X, Kanatzidis MG (2014) Highly selective and efficient heavy metal capture with polysulfide intercalated layered double hydroxides. J Mater Chem A 2:10280–10289

  17. 17.

    Ai X, Wang Y, Hou X, Yang L, Zheng C, Wu L (2013) Advanced oxidation using Fe3O4 magnetic nanoparticles and its application in mercury speciation analysis by high performance liquid chromatography-cold vapor generation atomic fluorescence spectrometry.  Analyst 138:3494–3501

  18. 18.

    da Silva MJ, Paim APS, Pimentel MF, Cervera ML, de la Guardia M (2010) Determination of mercury in rice by cold vapor atomic fluorescence spectrometry after microwave-assisted digestion. Anal Chim Acta 66:743–748

  19. 19.

    Yu JC, Lo JM, Wai KM (1983) Extraction of gold and mercury from sea water with bismuth diethyldithiocarbamate prior to neutron activation-γ-spectrometry. Anal Chim Acta 154307–312

  20. 20.

    Ugo P, Mortto L, Bertoneell P, Wang J (1998)Determination of Trace Mercury in Saltwaters at Screen‐Printed Electrodes Modified with Sumichelate Q10R.  Electroanalysis 10:1017–1021

  21. 21.

    Lee SJ, Moskovits M (2011) Visualizing chromatographic separation of metal ions on a surface-enhanced Raman active medium. Nano Lett 11:145–150

  22. 22.

    Du Y, Liu R, Liu B, Wang S, Han M-Y, Zhang Z (2013) Surface-enhanced Raman scattering chip for femtomolar detection of mercuric ion (II) by ligand exchange. Anal Chem 85:3160–3165

  23. 23.

    Zhou Y, Yoon J (2012) Recent progress in fluorescent and colorimetric chemosensors for detection of amino acids. Chem Soc Rev 41:52–67

  24. 24.

    Kaur B, Kaur N, Kumar S (2018) Colorimetric metal ion sensors–a comprehensive review of the years 2011–2016. Coord Chem Rev 358:13–69

  25. 25.

    Jeong Y, Yoon J (2012) Recent progress on fluorescent chemosensors for metal ions. Inorganica Chim Acta 381:2–14

  26. 26.

    Chae M-Y, Czarnik AW (1992) Fluorometric chemodosimetry. Mercury (II) and silver (I) indication in water via enhanced fluorescence signaling. J Am Chem Soc 114:9704–9705

  27. 27.

    El-Shekheby HA, Mangood AH, Hamza SM, Al‐Kady AS, Ebeid EZM (2014)  A highly efficient and selective turn‐on fluorescent sensor for Hg2+, Ag+ and Ag nanoparticles based on a coumarin dithioate derivative. Luminescence 29158–167

  28. 28.

    Ngororabanga JMV, Tshentu ZR, Mama N (2019) A highly selective and sensitive ESIPT-based coumarin–triazole polymer for the ratiometric detection of Hg2+. New J Chem 43:12168–12177

  29. 29.

    Ko S-K, Yang Y-K, Tae J, Shin I (2006) In vivo monitoring of mercury ions using a rhodamine-based molecular probe.  J Am Chem Soc 128:14150–14155

  30. 30.

    Luo J, Jiang S, Qin S, Wu H, Wang Y, Jiang J, Liu X (2011) Highly sensitive and selective turn-on fluorescent chemosensor for Hg2+ in pure water based on a rhodamine containing water-soluble copolymer. Sens Actuators B-Chem 160:1191–1197

  31. 31.

    Nolan EM, Lippard SJ (2007) Turn-on and ratiometric mercury sensing in water with a red-emitting probe. J Am Chem Soc 129:5910–5918

  32. 32.

    Sivaraman G, Anand T, Chellappa D (2012) Development of a pyrene based “turn on” fluorescent chemosensor for Hg2+. RSC Adv 2:10605–10609

  33. 33.

    Gao Y, Ma T, Ou Z, Cai W, Yang G, Li Y, Xu M, Li Q (2018) Highly sensitive and selective turn-on fluorescent chemosensors for Hg2+ based on thioacetal modified pyrene. Talanta 178:663–669

  34. 34.

    Zhou S, Zhou ZQ, Zhao XX, Xiao YH, Xi G, Liu JT, Zhao BX (2015) A dansyl based fluorescence chemosensor for Hg2+ and its application in the complicated environment samples. Spectrochim Acta Part A 148:348–354

  35. 35.

    Zhao Y, Zhong Z (2006) Detection of Hg2+ in aqueous solutions with a foldamer-based fluorescent sensor modulated by surfactant micelles. Org lett 8:4715–4717

  36. 36.

    Bhalla V, Tejpal R, Kumar M, Puri RK, Mahajan RK (2009) Terphenyl based ‘Turn On’fluorescent sensor for mercury. Tetrahedron Lett 50:2649–2652

  37. 37.

    Fang Y, Zhou Y, Li JY, Rui QQ, Yao C (2015) Naphthalimide–Rhodamine based chemosensors for colorimetric and fluorescent sensing Hg2+ through different signaling mechanisms in corresponding solvent systems. Sens Actuators B-Chem 215:350–359

  38. 38.

    Lin Q, Mao PP, Fan YQ, Liu L, Liu J, Zhang YM, Yao H, Wei TB (2017) A novel supramolecular polymer gel based on naphthalimide functionalized-pillar [5] arene for the fluorescence detection of Hg2+ and I− and recyclable removal of Hg2+ via cation–π interactions. Soft matter 13:7085–7089

  39. 39.

    Yan Y, Zhang Y, Xu H (2013) A Selective “Turn‐On” Fluorescent Probe for Recognition of Mercury (II) Ions in Aqueous Solution Based on a Desulfurization Reaction. ChemPlusChem 78:628–631

  40. 40.

    Chen X, Pradhan T, Wang F, Kim JS, Yoon J (2011) Fluorescent chemosensors based on spiroring-opening of xanthenes and related derivatives. Chem Rev 112:1910–1956

  41. 41.

    Jiang W, Wang W (2009) A selective and sensitive “turn-on” fluorescent chemodosimeter for Hg2+ in aqueous media via Hg2+ promoted facile desulfurization–lactonization reaction. Chem Commun 26:3913–3915

  42. 42.

    Liu B, Tian H (2005) A selective fluorescent ratiometric chemodosimeter for mercury ion. Chem Commun 25:3156–3158

  43. 43.

    Lv F, Feng X, Tang H, Liu L, Yang Q, Wang S (2011) Development of film sensors based on conjugated polymers for copper (II) ion detection. Adv Funct Mat 21:845–850

  44. 44.

    García JM, García FC, Serna F, de la Peña JL (2010) High-performance aromatic polyamides. Prog Polym Sci 35:623–686

  45. 45.

    Anzenbacher Jr P, Liuand Y, Kozelkova ME (2010) Hydrophilic polymer matrices in optical array sensing. Curr Opin Chem Biol 14:693–704

  46. 46.

    Rotello V, Thayumanavan S (2008). In: Thayumanavan V (ed) Molecular Recognition and Polymers: Control of Polymer Structure and Self-Assembly, Rotello. Wiley, Hoboken

  47. 47.

    Gu C, Huang N, Wu Y, Xu H, Jiang D (2015) Design of highly photofunctional porous polymer films with controlled thickness and prominent microporosity. Angew Chem Int Ed 54:11540–11544

  48. 48.

    Lee DN, Kim GJ, Kim HJ (2009) A fluorescent coumarinylalkyne probe for the selective detection of mercury (II) ion in water. Tetrahedron Lett 50:4766–4768

  49. 49.

    Kutscheroff MG (1909) On the hydration of the hydrocarbons of the acetylene series by cadmium, zinc and magnesium salts. Reports of the German Chemical Society 42(2):2759–2762

  50. 50.

    Budde WL, Dessy RE (1963) The homogeneously catalyzed hydration of acetylenes by mercuric perchlorate-perchloric acid: Evidence for a bis-(acetylene)-mercuric ion complex as an intermediate. J Am Chem Soc 85:3964–3970

  51. 51.

    Song F, Watanabe S, Floreancig PE, Koide K (2008) Oxidation-resistant fluorogenic probe for mercury based on alkyne oxymercuration. J Am Chem Soc 130:16460–16461

  52. 52.

    Hintermann L (2007) Catalytic hydration of alkynes and its application in synthesis. Labonne A 8:1121–1150

  53. 53.

    RostovtsevL VV. Green G, Fokin VV, Sharpless KB (2002) A stepwise huisgen cycloaddition process: copper (I)‐catalyzed regioselective “ligation” of azides and terminal alkynes. Angew Chem Int Ed 41:2596–2599

  54. 54.

    Meldal M, Tornøe CW (2008) Cu-catalyzed azide− alkyne cycloaddition. Chem Rev 108:2952–3015

  55. 55.

    Wu JS, Liu WM, Zhuang XQ, Wang F, Wang PF, Tao SL, Zhang XH, Wu SK, Lee ST (2007)  Fluorescence turn on of coumarin derivatives by metal cations: a new signaling mechanism based on C= N isomerization. Org lett 9:33–36

  56. 56.

    Jõgi A, Mäeorg U (2001) Zn mediated regioselective Barbier reaction of propargylic bromides in THF/aq. NH4Cl solution. Molecules 6:964–968

  57. 57.

    Adapa PK, Schonenau LG, Canam T, Dumonceaux T (2011) Quantitative analysis of lignocellulosic components of non-treated and steam exploded barley, canola, oat and wheat straw using Fourier transform infrared spectroscopy. J Agric Sci Technol 1:177–188

  58. 58.

    Roy R, Rakshit S, Bhar S, Bhattacharya SC (2015) A colorimetric and turn-on fluorescent chemosensor for selective detection of Hg2+: theoretical studies and intracellular applications. RSC Adv 5:67833–67840

  59. 59.

    McClure DS (1952) Spin‐orbit interaction in aromatic molecules. J Chem Phys 20:682–686

  60. 60.

    Masuhara H, Shioyama H, Saito T, Hamada K, Yasoshima S, Mataga N (1984) Fluorescence quenching mechanism of aromatic hydrocarbons by closed-shell heavy metal ions in aqueous and organic solutions. J Phys Chem 88:5868–5873

  61. 61.

    Bassetti M, Floris B, Spadafora G (1986) Metalation of alkynes. 1. Effect of alkyne structure on the rate of acetoxymercuration. J Org Chem 51:4140–4143

  62. 62.

    Larock RC, Burns LD, Varaprath S, Russell CE (1987) Mercury in organic chemistry. 34. Synthesis of vinylmercurials via mercuration of propargylic amines. Organometallics 6:1780–1789

  63. 63.

    Nishizawa M, Imagawa H, Yamamoto H (2010) A new catalyst for organic synthesis: mercuric triflate. Org Biomol Chem 8:511–521

  64. 64.

    Renny JS, Tomasevich LL, Tallmadge EH, Collum DB (2013) Method of continuous variations: applications of job plots to the study of molecular associations in organometallic chemistry. Angew Chem Int Ed 52:11998–12013

  65. 65.

    Dong M, Ma T, Zhang A, Dong Y, Wang Y, Peng Y (2010) A series of highly sensitive and selective fluorescent and colorimetric “off-on” chemosensors for Cu (II) based on rhodamine derivatives. Dyes Pigm 87:164–172

  66. 66.

    Jana A, Kim JS, Jung HS, Bharadwaj PK (2009) A cryptand based chemodosimetric probe for naked-eye detection of mercury(ii) ion in aqueous medium and its application in live cell imaging. Chem Commun 29:4417–4419

  67. 67.

    Dong Z, Tian X, Chen Y, Hou J, Guo Y, Sun J, Ma J (2013) A highly selective fluorescent chemosensor for Hg2+ based on rhodamine B and its application as a molecular logic gate. Dyes Pigm 97:324–329

  68. 68.

    Benesi HA, Hildebrand JH (1949)  A spectrophotometric investigation of the interaction of iodine with aromatic hydrocarbons. J Am Chem Soc 71:2703–2707

  69. 69.

    Wang L, Ye D, Cao D (2012)  A novel coumarin Schiff-base as a Ni (II) ion colorimetric sensor. Spectrochim Acta Part A 90:40–44

  70. 70.

    Ho IT, Lai TL, Wu RT, Tsai MT, Wu CM, Lee GH, Chung WS (2012) Design and synthesis of triazolyl coumarins as Hg2+ selective fluorescent chemosensors. Analyst 137:5770–5776

  71. 71.

    Hande PE, Samui AB, Kulkarni PS (2017) Selective nanomolar detection of mercury using coumarin based fluorescent Hg (II)-Ion imprinted polymer. Sens Actuator B-Chem 246:597–605

  72. 72.

    Roy R, Rakshit S, Bhar S, Bhattacharya SC (2015) A colorimetric and turn-on fluorescent chemosensor for selective detection of Hg2+: theoretical studies and intracellular applications. RSC Adv 5:67833–67840

  73. 73.

    Gu B, Huang L, Mi N, Yin P, Zhang Y, Tu X, Luo X, Luo S, Yaoa S (2015) An ESIPT-based fluorescent probe for highly selective and ratiometric detection of mercury (II) in solution and in cells. Analyst 140:2778–2784

  74. 74.

    Hu J, Hu Z, Liu S, Zhang Q, H.-W.Gao and Uvdal K (2016) A new ratiometric fluorescent chemodosimeter based on an ICT modulation for the detection of Hg2+. Sens Actuators B-Chem 230:639–644

  75. 75.

    Feng L, Sha J, He Y, Chen S, Liu B, Zhang H, Lü C (2015) Conjugated polymer and spirolactam rhodamine-B derivative co-functionalized mesoporous silica nanoparticles as the scaffold for the FRET-based ratiometric sensing of mercury (II) ions. Microporous Mesoporous Mater 208:113–119

  76. 76.

    Sie YW, Li CL, Wan CF, Chen JH, Hu CH, Wu AT (2018) 1, 10-Phenanthroline based colorimetric and fluorescent sensor for Hg2+ in water: Experimental and DFT study. Inorganica Chim Acta 469:397–401

  77. 77.

    Cheng X, Qu S, Xiao L, Li W, He P (2018) Thioacetalized coumarin-based fluorescent probe for mercury (II): ratiometric response, high selectivity and successful bioimaging application. J Photochem Photobiol A: Chem 364:503–509

  78. 78.

    Jiao Y, Liu X, Zhou L, He H, Zhou P, Duan C (2017) A schiff-base dual emission ratiometric fluorescent chemosensor for Hg2+ ions and its application in cellular imaging. Sens Actuators B-Chem 247:950–956

  79. 79.

    Ondigo DA, Tshentu ZR, Torto N (2013) Electrospun nanofiber based colorimetric probe for rapid detection of Fe2+ in water. Anal Chim Acta 804:228–234

  80. 80.

    Fernández-Ramos MD, Cuadros-Rodríguez L, Arroyo-Guerrero E, Capitán-Vallvey LF (2011) An IUPAC-based approach to estimate the detection limit in co-extraction-based optical sensors for anions with sigmoidal response calibration curves. Anal Bioanal Chem 401:2881–2889

  81. 81.

    World Health Organization (2003) Background document for development of WHO Guidelines for Drinking-water Quality. World Health Organization

  82. 82.

    García JM, García FC, Serna F, de la Peña JL (2011) Fluorogenic and chromogenic polymer chemosensors. Poly Rev 51:341–390

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For this work, we acknowledge the Nelson Mandela University (NMU) for funding and facilities to carry out this research.

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Ngororabanga, J.M.V., Tshentu, Z.R. & Mama, N. A New Highly Selective Colorimetric and Fluorometric Coumarin-based Chemosensor for Hg2+. J Fluoresc (2020). https://doi.org/10.1007/s10895-020-02542-x

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  • Recognition events
  • ICT
  • Functional linkage
  • Fluorescence quenching
  • Post-polymerization functionalization