Microchimica Acta

, 186:404 | Cite as

3D-printed CuO nanoparticlefunctionalized flow reactor enables online fluorometric monitoring of glucose

  • Cheng-Kuan SuEmail author
  • Hsin-Heng Tseng
Original Paper


An online flow reactor was fabricated by using a fused deposition modeling three-dimensional printing (3DP) technology along with thermoplastic poly(lactic acid) filaments incorporating copper oxide nanoparticles (CuO NPs). In the presence of glucose, the flow reactor displays multi-catalytic activities because accelerates the oxidation of 2′,7′-dichlorodihydrofluorescein to form fluorescein which displays green fluorescence under 480 nm excitation (emission wavelength: 530 nm). The CuO NPs exert two functions to mediate electron transfer at a basic reaction condition, viz. direct oxidation of glucose to generate reactive oxygen species (ROS), and prompting the ROS to oxidize 2′,7′-dichlorofluorescin diacetate. The flow reactor coupled to a microdialysis sampler and a fluorometer was applied for online fluorometric monitoring of brain extracellular glucose levels in living rats based on scanning of time-resolved fluorescence intensities. After optimization of (a) the manufacture of the flow reactor, (b) the reaction conditions (pH 10; 50 °C), and (c) the online analytical system, the detection limit of the method (when using 10-μL samples of microdialysate) is as low as 6.1 μM (linear range: 0.05–5 mM) with a sampling frequency of 7.5 h−1. To illustrate the method’s applicability, analyses of spiked off-line-collected rat brain microdialysates were conducted. In addition, rat brain extracellular glucose levels were monitored in-vivo and online upon neuronal depolarization triggered by perfusing a high-K+ medium. The results demonstrate that functionalizing raw 3DP materials with appropriate nanomaterials can simplify the manufacturing of analytical devices and related analytical procedures. This will extend the diversity and adaptability of current 3DP-enabling analytical strategies.

Graphical abstract

Schematic presentation of an online flow reactor fabricated using a fused deposition modeling 3D printer along with poly(lactic acid) (PLA) filaments incorporating CuO NPs. The manufactured flow reactor displays multi-catalytic activities and simplifies online fluorometric monitoring of living rat brain extracellular glucose.


Additive manufacturing Brain extracellular fluid CuO nanoparticles DCFH-DA Enzyme mimic In vivo monitoring Incorporation Reactive oxygen species 



We thank Professor Yuh-Chang Sun for providing helpful advice, and the Ministry of Science and Technology of the Republic of China for financial support (grant MOST 106-2113-M-019-002-MY2).

Compliance with ethical standards

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

Supplementary material

604_2019_3512_MOESM1_ESM.doc (6.9 mb)
ESM 1 (DOC 7068 kb)


  1. 1.
    Dienel GA, Hertz L (2001) Glucose and lactate metabolism during brain activation. J Neurosci Res 66:824–838CrossRefGoogle Scholar
  2. 2.
    Abi-Saab WM, Maggs DG, Jones T, Jacob R, Srihari V, Thompson J, Kerr D, Leone P, Krystal JH, Spencer DD, During MJ, Sherwin RS (2002) Striking differences in glucose and lactate levels between brain extracellular fluid and plasma in conscious human subjects: effects of hyperglycemia and hypoglycemia. J Cereb Blood Flow Metab 22:271–279CrossRefGoogle Scholar
  3. 3.
    Parkin MC, Hopwood SE, Strong AJ, Boutelle MG (2003) Resolving dynamic changes in brain metabolism using biosensors and on-line microdialysis. TrAC—Trends Anal Chem 22:487–497CrossRefGoogle Scholar
  4. 4.
    Zhang M, Mao L (2005) Enzyme-based amperometric biosensors for continuous and on-line monitoring of cerebral extracellular microdialysate. Front Biosci 10:345–352CrossRefGoogle Scholar
  5. 5.
    Bélanger M, Allaman I, Magistretti PJ (2011) Brain energy metabolism: focus on astrocyte-neuron metabolic cooperation. Cell Metab 14:724–738CrossRefGoogle Scholar
  6. 6.
    De la Monte SM, Tong M (2014) Brain metabolic dysfunction at the core of Alzheimer’s disease. Biochem Pharmacol 88:548–559CrossRefGoogle Scholar
  7. 7.
    Hao J, Xiao T, Wu F, Yu P, Mao L (2016) High antifouling property of ion-selective membrane: toward in vivo monitoring of pH change in live brain of rats with membrane-coated carbon fiber electrodes. Anal Chem 88:11238–11243CrossRefGoogle Scholar
  8. 8.
    Singh YS, Sawarynski LE, Dabiri PD, Choi WR, Andrews AM (2011) Comparisons of carbon fiber microelectrode coatings for sensitive and selective neurotransmitter detection by voltammetry. Anal Chem 83:6658–6666CrossRefGoogle Scholar
  9. 9.
    Watson CJ, Venton BJ, Kennedy RT (2006) In vivo measurements of neurotransmitters by microdialysis sampling. Anal Chem 78:1391–1399CrossRefGoogle Scholar
  10. 10.
    Moon BU, de Vries MG, Cordeiro CA, Westerink BHC, Verpoorte E (2013) Microdialysis-coupled enzymatic microreactor for in vivo glucose monitoring in rats. Anal Chem 85:10949–10955CrossRefGoogle Scholar
  11. 11.
    Mross S, Pierrat S, Zimmermann T, Kraft M (2015) Microfluidic enzymatic biosensing systems: a review. Biosens Bioelectron 70:376–391CrossRefGoogle Scholar
  12. 12.
    Gross B, Lockwood SY, Spence DM (2017) Recent advances in analytical chemistry by 3D printing. Anal Chem 89:57–70CrossRefGoogle Scholar
  13. 13.
    Palenzuela CLM, Pumera M (2018) (Bio)analytical chemistry enabled by 3D printing: sensors and biosensors. TrAC—Trends Anal Chem 103:110–118CrossRefGoogle Scholar
  14. 14.
    Kalsoom U, Nesterenko PN, Paull B (2018) Current and future impact of 3D printing on the separation sciences. TrAC—Trends Anal Chem 105:429–502CrossRefGoogle Scholar
  15. 15.
    Symes MD, Kitson PJ, Yan J, Richmond CJ, Cooper GJT, Bowman RW, Vilbrandt T, Cronin L (2012) Integrated 3D-printed reactionware for chemical synthesis and analysis. Nat Chem 4:349–354CrossRefGoogle Scholar
  16. 16.
    Su CK, Chen JC (2017) Reusable, 3D-printed, peroxidase mimic–incorporating multi-well plate for high-throughput glucose determination. Sens Actuators B—Chem 247:641–647CrossRefGoogle Scholar
  17. 17.
    Nadgorny M, Ameli A (2018) Functional polymers and nanocomposites for 3D printing of smart structures and devices. ACS Appl Mater Interfaces 10:17489–17507CrossRefGoogle Scholar
  18. 18.
    Wei H, Wang E (2013) Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes. Chem Soc Rev 42:6060–6093CrossRefGoogle Scholar
  19. 19.
    Wang X, Hu Y, Wei H (2016) Nanozymes in bionanotechnology: from sensing to therapeutics and beyond. Inorg Chem Front 3:41–60CrossRefGoogle Scholar
  20. 20.
    Hua AL, Deng HH, Zheng XQ, Wu YY, Lin XL, Liu AL, Xia XH, Peng HP, Chen W, Hong GL (2017) Self-cascade reaction catalyzed by CuO nanoparticle-based dual-functional enzyme mimics. Biosens Bioelectron 97:21–25CrossRefGoogle Scholar
  21. 21.
    Qiao F, Wang F, Xu K, Ai S (2015) Double enzymatic cascade reactions within FeSe–Pt@SiO2 nnanospheres: synthesis and application toward colorimetric biosensing of H2O2 and glucose. Analyst 140:6684–6691CrossRefGoogle Scholar
  22. 22.
    Li H, Wang T, Wang Y, Wang S, Su P, Yang Y (2018) Intrinsic triple-enzyme mimetic activity of V6O13 nanotextiles: mechanism investigation and colorimetric and fluorescent detections. Ind Eng Chem Res 57:2416–2425CrossRefGoogle Scholar
  23. 23.
    Rahman MM, Ahammad AJS, Jin JH, Ahn SJ, Lee JJ (2016) A comprehensive review of glucose biosensors based on nanostructured metal-oxides. Sensors 10:4855–4886CrossRefGoogle Scholar
  24. 24.
    Fee C, Nawada S, Dimartino S (2014) 3D printed porous media columns with fine control of column packing morphology. J Chromatogr A 1333:18–24CrossRefGoogle Scholar
  25. 25.
    Paxinos G, Watson C (2007) The rat brain in stereotaxic coordinates, 6th edn. Elsevier, AmsterdamGoogle Scholar
  26. 26.
    Kalyanaraman B, Darley-Usmar V, Davies KJA, Dennery PA, Forman HJ, Grisham MB, Mann GE, Moore K, Roberts LJ, Ischiropoulos H (2012) Measuring reactive oxygen and nitrogen species with fluorescent probes: challenges and limitations. Free Radic Biol Med 52:1–6CrossRefGoogle Scholar
  27. 27.
    Su CK, Peng PJ, Sun YC (2015) Fully 3D-printed preconcentrator for selective extraction of trace elements in seawater. Anal Chem 87:6945–6950CrossRefGoogle Scholar
  28. 28.
    Bokare AD, Choi W (2014) Review of iron-free Fenton-like systems for activating H2O2 in advanced oxidation processes. J Hazard Mater 275:121–135CrossRefGoogle Scholar
  29. 29.
    Fang Q, Shi XT, Sun YQ, Fang ZL (1997) A flow injection microdialysis sampling chemiluminescence system for in vivo on-line monitoring of glucose in intravenous and subcutaneous tissue fluid microdialysates. Anal Chem 69:3570–3577CrossRefGoogle Scholar
  30. 30.
    Li B, Zhang Z, Jin Y (2001) Chemiluminescence flow sensor for in vivo on-line monitoring of glucose in awake rabbit by microdialysis sampling. Anal Chim Acta 432:95–100CrossRefGoogle Scholar
  31. 31.
    Liu W, Zhang Z, Liu H (2005) Droplet-based micro-flow chemiluminescence system for in vivo glucose determination by microdialysis sampling. Anal Sci 21:413–416CrossRefGoogle Scholar
  32. 32.
    Wang M, Roman GT, Schultz K, Jennings C, Kennedy RT (2008) Improved temporal resolution for in vivo microdialysis by using segmented flow. Anal Chem 80:5607–5615CrossRefGoogle Scholar
  33. 33.
    Su CK, Chen CY, Tseng PJ, Sun YC (2015) Using copper ions to amplify ROS-mediated fluorescence for continuous online monitoring of extracellular glucose in living rat brain. Biosens Bioelectron 64:535–541CrossRefGoogle Scholar
  34. 34.
    Su CK, Yen SC, Li TW, Sun YC (2016) Enzyme-immobilized 3D-printed reactors for online monitoring of rat brain extracellular glucose and lactate. Anal Chem 88:6265–6273CrossRefGoogle Scholar
  35. 35.
    Hopwood SE, Parkin MC, Bezzina EL, Boutelle MG, Strong AJ (2005) Transient changes in cortical glucose and lactate levels associated with peri-infarct depolarisations, studied with rapid-sampling microdialysis. J Cereb Blood Flow Metab 25:391–401CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Bioscience and BiotechnologyNational Taiwan Ocean UniversityKeelungTaiwan

Personalised recommendations