Microchimica Acta

, 186:27 | Cite as

A liquid crystal based method for detection of urease activity and heavy metal ions by using stimulus-responsive surfactant-encapsulated phosphotungstate clusters

  • Lubin Qi
  • Qiongzheng Hu
  • Qi Kang
  • Li Yu
Original Paper


A liquid crystal (LC) based method is described for the sensitive determination of the activity of urease and of heavy metal ions which acts as inhibitors. Stimulus-responsive surfactant-encapsulated phosphotungstate clusters (SECs) were fabricated and deposited onto octadecyltrichlorosilane-coated glass. A copper TEM grid filled with LCs was placed on the substrate to construct the LC optical cell. Upon addition of water to the LC interface, the optical appearance of LCs on the glass undergoes a bright-to-dark shift due to an orientational transition of the LCs from a planar to a homeotropic state. However, the LCs display a bright appearance if they are pretreated with an aqueous solution containing urea and urease. This is caused by the disassemby of the SECs from the glass surface due to an increase of the pH value that is induced by the enzymatic hydrolysis of urea by urease. The method is highly sensitive and can detect urease activities as low as 0.03 mU/mL. It can also be applied to the determination of heavy metal ions which exert an inhibitory effect on the activity of urease. For example, Cu(II) can be quantified via urease inhibition in 1 nM concentration.

Graphical abstract

Schematic presentation of a liquid crystal-based sensor for detection of urease and heavy metal ions by using stimulus-responsive surfactant-encapsulated phosphotungstate clusters.


Liquid crystal Sensor layer Urease Stimulus-responsive material Nanocomposites Ionic liquid Surfactant Polyoxometalates Ionic self-assembly 



This work was supported by the National Natural Science Foundation of China (No. 21373128), Scientific and Technological Projects of Shandong Province of China (No. 2018GSF121024).

Compliance with ethical standards

The author(s) declare that they have no competing interests.

Supplementary material

604_2018_3132_MOESM1_ESM.doc (13.7 mb)
ESM 1 (DOC 14074 kb)


  1. 1.
    Siddiq D, Darouiche R (2012) New strategies to prevent catheter-associated urinary tract infections. Nat Rev Urol 9:305–314. CrossRefPubMedGoogle Scholar
  2. 2.
    Lan J, Li L, Liu Y, Yan L, Li C, Chen J, Chen X (2016) Upconversion luminescence assay for the detection of the vascular endothelial growth factor, a biomarker for breast cancer. Microchim Acta 183:3201–3208. CrossRefGoogle Scholar
  3. 3.
    Hun X, Liu B, Meng Y (2017) Ultrasensitive chemiluminescence assay for the lung cancer biomarker cytokeratin 21-1 via a dual amplification scheme based on the use of encoded gold nanoparticles and a toehold-mediated strand displacement reaction. Microchim Acta 184:3953–3959. CrossRefGoogle Scholar
  4. 4.
    Karimi M, Hosseini M, Faridbod F, Ganjali M (2017) Highly sensitive label-free electrochemiluminescence aptasensor for early detection of myoglobin, a biomarker for myocardial infarction. Microchim Acta 184:3529–3537. CrossRefGoogle Scholar
  5. 5.
    Martínez G, Sánchez E, González A, Yáñez P, Pingarrón J (2018) Amperometric immunoassay for the obesity biomarker amylin using a screen printed carbon electrode functionalized with an electropolymerized carboxylated polypyrrole. Microchim Acta 185:323. CrossRefGoogle Scholar
  6. 6.
    Wang H, Ma Z (2017) Ultrasensitive amperometric detection of the tumor biomarker cytokeratin antigen using a hydrogel composite consisting of phytic acid, Pb(II) ions and gold nanoparticles. Microchim Acta 184:1045–1050. CrossRefGoogle Scholar
  7. 7.
    Stickler D, Jones S, Adusei G, Waters M, Cloete J, Mathur S, Feneley R (2006) A clinical assessment of the performance of a sensor to detect crystalline biofilm formation on indwelling bladder catheters. BJU Int 98:1244–1249. CrossRefPubMedGoogle Scholar
  8. 8.
    Gong Y, Hu Q, Wang C, Zang L, Yu L (2016) Stimuli-responsive Polyoxometalate/ionic liquid supramolecular spheres: fabrication, characterization, and biological applications. Langmuir 32:421–427. CrossRefPubMedGoogle Scholar
  9. 9.
    Surender E, Bradberry S, Bright S, McCoy C, Williams D, Gunnlaugsson T (2017) Luminescent lanthanide Cyclen-based enzymatic assay capable of diagnosing the onset of catheter-associated urinary tract infections both in solution and within polymeric hydrogels. J Am Chem Soc 139:381–388. CrossRefPubMedGoogle Scholar
  10. 10.
    Lonsdale W, Maurya D, Wajrak M, Tay C, Marshall B, Alameh K (2017) Rapid measurement of urease activity using a potentiometric RuO 2 pH sensor for detection of helicobacter pylori. Sensors Actuators B Chem 242:1305–1308. CrossRefGoogle Scholar
  11. 11.
    Hussain Z, Qazi F, Ahmed M, Usman A, Riaz A, Abbasi A (2016) Liquid crystals based sensing platform-technological aspects. Biosens Bioelectron 85:110–127. CrossRefPubMedGoogle Scholar
  12. 12.
    Brake J, Daschner M, Luk Y, Abbott N (2003) Biomolecular interactions at phospholipid-decorated surfaces of liquid crystals. Science 302:2094–2097. CrossRefPubMedGoogle Scholar
  13. 13.
    Chang C, Chen C (2014) Oligopeptide-decorated liquid crystal droplets for detecting proteases. Chem Commun 50:12162–12165. CrossRefGoogle Scholar
  14. 14.
    Zhao D, Peng Y, Xu L, Zhou W, Wang Q, Guo L (2015) Liquid-crystal biosensor based on nickel-Nanosphere-induced Homeotropic alignment for the amplified detection of thrombin. ACS Appl Mater Interfaces 7:23418–23422. CrossRefPubMedGoogle Scholar
  15. 15.
    Sadati M, Apik A, Armas-Perez J, Martinez-Gonzalez J, Hernandez-Ortiz J, Abbott N, de Pablo J (2015) Liquid crystal enabled early stage detection of Beta amyloid formation on lipid monolayers. Adv Funct Mater 25:6050–6060. CrossRefGoogle Scholar
  16. 16.
    Ding X, Yang K (2013) Antibody-free detection of human chorionic gonadotropin by use of liquid crystals. Anal Chem 85:10710–10716. CrossRefPubMedGoogle Scholar
  17. 17.
    Tan H, Yang S, Shen G, Yu R, Wu Z (2010) Signal-enhanced liquid-crystal DNA biosensors based on enzymatic metal deposition. Angew Chem Int Ed 49:8608–8611. CrossRefGoogle Scholar
  18. 18.
    Price A, Schwartz D (2008) DNA hybridization-induced reorientation of liquid crystal anchoring at the nematic liquid crystal/aqueous interface. J Am Chem Soc 130:8188–8194. CrossRefPubMedGoogle Scholar
  19. 19.
    Shen J, He F, Chen L, Ding L, Liu H, Wang Y, Xiong X (2017) Liquid crystal-based detection of DNA hybridization using surface immobilized single-stranded DNA. Microchim Acta 184:3137–3144. CrossRefGoogle Scholar
  20. 20.
    Hu Q, Jang C (2011) Liquid crystal-based sensors for the detection of heavy metals using surface-immobilized urease. Colloid surface B 88:622–626. CrossRefGoogle Scholar
  21. 21.
    Chen C, Lin Y, Chang H, Lee A (2015) Ligand-doped liquid crystal sensor system for detecting mercuric ion in aqueous solutions. Anal Chem 87:4546–4551. CrossRefPubMedGoogle Scholar
  22. 22.
    Sivakumar S, Wark K, Gupta J, Abbott N, Caruso F (2009) Liquid crystal emulsions as the basis of biological sensors for the optical detection of Bacteria and viruses. Adv Funct Mater 19:2260–2265. CrossRefGoogle Scholar
  23. 23.
    Li X, Li G, Yang M, Chen L, Xiong X (2015) Gold nanoparticle based signal enhancement liquid crystal biosensors for tyrosine assays. Sensors Actuators B Chem 215:152–158. CrossRefGoogle Scholar
  24. 24.
    Wang Y, Wang B, Shen J, Xiong X, Deng S (2017) Aptamer based bare eye detection of kanamycin by using a liquid crystal film on a glass support. Microchim Acta 184:3765–3771. CrossRefGoogle Scholar
  25. 25.
    Bi X, Hartono D, Yang K (2009) Real-time liquid crystal pH sensor for monitoring enzymatic activities of penicillinase. Adv Funct Mater 19:3760–3765. CrossRefGoogle Scholar
  26. 26.
    Zhong S, Jang C (2014) Highly sensitive and selective glucose sensor based on ultraviolet-treated nematic liquid crystals. Biosens Bioelectron 59:293–299. CrossRefPubMedGoogle Scholar
  27. 27.
    Khan M, Park S (2014) Liquid crystal-based proton sensitive glucose biosensor. Anal Chem 86:1493–1501. CrossRefPubMedGoogle Scholar
  28. 28.
    He Z, Yan Y, Li B, Ai H, Wang H, Li H, Wu L (2012) Thermal-induced dynamic self-assembly of adenine-grafted polyoxometalate complexes. Dalton Trans 41:10043. CrossRefPubMedGoogle Scholar
  29. 29.
    Song Y, Tsunashima R (2012) Recent advances on polyoxometalate-based molecular and composite materials. Chem Soc Rev 41:7384–7403. CrossRefPubMedGoogle Scholar
  30. 30.
    Volkmer D, Chesne A, Kurth D, Schnablegger H, Lehmann P, Koop M, Muller A (2000) Toward nanodevices: synthesis and characterization of the nanoporous surfactant-encapsulated keplerate (DODA)40(NH4)2[(H2O)n⊂Mo132O372(CH3COO)30(H2O)72]. J Am Chem Soc 122:1995–1998. CrossRefGoogle Scholar
  31. 31.
    Wang S, Yang G (2015) Recent advances in polyoxometalate-catalyzed reactions. Chem Rev 115:4893–4962. CrossRefPubMedGoogle Scholar
  32. 32.
    Wang X, Liu J, Yu L, Jiao J, Wang R, Sun L (2013) Surface adsorption and micelle formation of imidazolium-based zwitterionic surface active ionic liquids in aqueous solution. J Colloid Interface Sci 391:103–110. CrossRefPubMedGoogle Scholar
  33. 33.
    Hu Q, Jang C (2012) Imaging trypsin activity through changes in the orientation of liquid crystals coupled to the interactions between a polyelectrolyte and a phospholipid layer. ACS Appl Mater Interfaces 4:1791–1795. CrossRefPubMedGoogle Scholar
  34. 34.
    Zhang T, Liu S, Kurth D, Faul C (2009) Organized Nanostructured Complexes of Polyoxometalates and Surfactants that Exhibit Photoluminescence and Electrochromism. Adv Funct Mater 19:642–652. CrossRefGoogle Scholar
  35. 35.
    Zhao M, Zhao Y, Zheng L, Dai C (2013) Construction of supramolecular self-assembled microfibers with fluorescent properties through a modified ionic self-assembly (ISA) strategy. Chem Eur J 19:1076–1081. CrossRefPubMedGoogle Scholar
  36. 36.
    Leng Y, Wang J, Zhu D, Zhang M, Zhao P, Long Z, Huang J (2011) Polyoxometalate-based amino-functionalized ionic solid catalysts lead to highly efficient heterogeneous epoxidation of alkenes with H2O2. Green Chem 13:1636. CrossRefGoogle Scholar
  37. 37.
    Preininger C, Wolfbeis O (1996) Disposable cuvette test with integrated sensor layer for enzymatic determination of heavy metals. Biosens Bioelectron 11:981–990. CrossRefGoogle Scholar
  38. 38.
    Deng H, Wu G, Zou Z, Peng H, Liu A, Lin X, Xia X, Chen W (2015) pH-sensitive gold nanoclusters: preparation and analytical applications for urea, urease, and urease inhibitor detection. Chem Commun 51:7847–7850. CrossRefGoogle Scholar
  39. 39.
    Liu D, Jang C (2014) A new strategy for imaging urease activity using liquid crystal droplet patterns formed on solid surfaces. Sensors Actuators B Chem 193:770–773. CrossRefGoogle Scholar
  40. 40.
    Hu Q, Jang C (2011) Using liquid crystals for the real-time detection of urease at aqueous/liquid crystal interfaces. J Mater Sci 47:969–975. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Key Laboratory of Colloid and Interface Chemistry, Ministry of EducationShandong UniversityJinanPeople’s Republic of China
  2. 2.Department of ChemistryUniversity of WashingtonSeattleUSA
  3. 3.College of Chemistry, Chemical Engineering and Materials ScienceShandong Normal UniversityJinanPeople’s Republic of China

Personalised recommendations