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Microfluidic-based ion-selective thermoplastic electrode array for point-of-care detection of potassium and sodium ions

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Abstract

A microfluidic paper-based thermoplastic electrode (TPE) array has been developed for point-of-care detection of Na+ and K+ ions using a custom-made portable potentiometer. TPEs were fabricated using polystyrene as the binder and two different types of graphite to compare the electrode performance. The newly designed TPE array embedded in a polymethyl methacrylate chip consists of two working electrodes modified with carbon black nanomaterial and an ion-selective membrane, and an all-solid-state reference electrode modified with Ag/AgCl ink and poly(butyl methacrylate-co-methyl methacrylate) membrane via drop-casting. Ion-selective membrane compositions and conditioning steps were optimized. Under optimized conditions, ion-selective TPEs demonstrated fast response time (4 s) and good stability. The TPE array demonstrated a Nernstian behavior for K+ with a sensitivity of 59.2 ± 0.2 mV decade−1 and near-Nernstian response for Na+ with a sensitivity of 54.0 ± 1.1 mV decade−1 in the range 10−1 – 10−4 M and 1 –  10−3 M, respectively. The detection limits were 1 × 10−5 M and 1 × 10−4 M for K+ and Na+, respectively. In addition, a K+ and Na+ selective microfluidic paper-based analytical device (µPAD) was applied to artificial serum analysis and found in good agreement with average recoveries of 101.3% and 99.7%, respectively, suggesting that the developed ISE array is suitable for detection of sodium and potassium in complex matrix.

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References

  1. Reddy KS, Katan MB (2004) Diet, nutrition and the prevention of hypertension and cardiovascular diseases. Public Health Nutr 7(1a):167–186

    Article  Google Scholar 

  2. Kopito L et al (1965) Studies in cystic fibrosis: analysis of nail clippings for sodium and potassium. N Engl J Med 272(10):504–509

    Article  CAS  PubMed  Google Scholar 

  3. Kelly JT et al (2017) Beyond sodium, phosphate and potassium: potential dietary interventions in kidney disease. Semin Dialysis30(3):197–202

  4. Gao X-P et al (2019) Admission serum sodium and potassium levels predict survival among critically ill patients with acute kidney injury: a cohort study. BMC Nephrol 20(1):1–10

    Article  Google Scholar 

  5. Pohl HR, Wheeler JS, Murray HE (2013) Sodium and potassium in health and disease. Interrelations between essential metal ions and human diseases 13(2013):29–47

  6. Pirovano P et al (2020) A wearable sensor for the detection of sodium and potassium in human sweat during exercise. Talanta 219:121145

    Article  CAS  PubMed  Google Scholar 

  7. El Otmani IS et al (2015) Correlation study between two analytical techniques used to measure serum potassium: an automated potentiometric method and flame photometry reference method. J Chem Pharmaceutical Res 7(8):862–867

    Google Scholar 

  8. Yu B-S, Nie L-H, Yao S-Z (1997) Ion chromatographic study of sodium, potassium and ammonium in human body fluids with bulk acoustic wave detection. J Chromatogr B Biomed Sci Appl 693(1):43–49

    Article  CAS  PubMed  Google Scholar 

  9. Chen H et al (2008) Potassium ion sensing using a self-assembled calix [4] crown monolayer by surface plasmon resonance. Sens Actuators, B Chem 133(2):577–581

    Article  CAS  Google Scholar 

  10. Dai H et al (2021) A new method for detecting Na+, K+‐ATPase activity by ICP‐MS: quantitative analysis on the inhibitory effect of rhein on Na+, K+‐ATPase activity by ICP‐MS in HCT116 cells. Biomed Chromatogr 35(12):5199

  11. Nayak S et al (2017) Point-of-care diagnostics: recent developments in a connected age. Anal Chem 89(1):102–123

    Article  CAS  PubMed  Google Scholar 

  12. Lynch A, Diamond D, Leader M (2000) Point-of-need diagnosis of cystic fibrosis using a potentiometric ion-selective electrode array. Analyst 125(12):2264–2267

    Article  CAS  PubMed  Google Scholar 

  13. Diamond D et al (2008) Wireless sensor networks and chemo-/biosensing. Chem Rev 108(2):652–679

    Article  CAS  PubMed  Google Scholar 

  14. Schazmann B et al (2010) A wearable electrochemical sensor for the real-time measurement of sweat sodium concentration. Anal Methods 2(4):342–348

    Article  CAS  Google Scholar 

  15. Glennon T et al (2016) ‘SWEATCH’: A wearable platform for harvesting and analysing sweat sodium content. Electroanalysis 28(6):1283–1289

    Article  CAS  Google Scholar 

  16. Bobacka J, Ivaska A, Lewenstam A (2008) Potentiometric ion sensors. Chem Rev 108(2):329–351

    Article  CAS  PubMed  Google Scholar 

  17. Roy S, David-Pur M, Hanein Y (2017) Carbon nanotube-based ion selective sensors for wearable applications. ACS Appl Mater Interfaces 9(40):35169–35177

    Article  CAS  PubMed  Google Scholar 

  18. Fibbioli M et al (2000) Potential drifts of solid-contacted ion-selective electrodes due to zero-current ion fluxes through the sensor membrane. Electroanalysis: An International Journal Devoted to Fundamental and Practical Aspects of Electroanalysis 12(16):1286–1292

    Article  CAS  Google Scholar 

  19. Jaramillo EA, Noell AC (2020) Development of miniature solid contact ion selective electrodes for in situ instrumentation. Electroanalysis 32(9):1896–1904

    Article  CAS  Google Scholar 

  20. Hu J, Stein A, Bühlmann P (2016) Rational design of all-solid-state ion-selective electrodes and reference electrodes. TrAC, Trends Anal Chem 76:102–114

    Article  CAS  Google Scholar 

  21. Khripoun GA et al (2006) Nitrate-selective solid contact electrodes with poly (3-octylthiophene) and poly (aniline) as ion-to-electron transducers buffered with electron-ion-exchanging resin. Electroanalysis An International Journal Devoted to Fundamental and Practical Aspects of Electroanalysis 18(13–14):1322–1328

    CAS  Google Scholar 

  22. Lai C-Z et al (2007) Ion-selective electrodes with three-dimensionally ordered macroporous carbon as the solid contact. Anal Chem 79(12):4621–4626

    Article  CAS  PubMed  Google Scholar 

  23. Paczosa-Bator B (2012) All-solid-state selective electrodes using carbon black. Talanta 93:424–427

    Article  CAS  PubMed  Google Scholar 

  24. Hu J et al (2015) All-solid-state reference electrodes based on colloid-imprinted mesoporous carbon and their application in disposable paper-based potentiometric sensing devices. Anal Chem 87(5):2981–2987

    Article  CAS  PubMed  Google Scholar 

  25. Lim H-R et al (2020) Ultrathin, long-term stable solid-state reference electrode enabled by enhanced interfacial adhesion and conformal coating of AgCl. Sensors and Actuators B: Chemical 309:127761

    Article  CAS  Google Scholar 

  26. Shinwari MW et al (2010) Microfabricated reference electrodes and their biosensing applications. Sensors 10(3):1679–1715

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Klunder KJ et al (2019) Polycaprolactone-enabled sealing and carbon composite electrode integration into electrochemical microfluidics. Lab Chip 19(15):2589–2597

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Ozer T et al (2021) Thermoplastic electrodes for detection of Escherichia coli. Journal of The Electrochemical Society 168(4):047509

    Article  CAS  Google Scholar 

  29. McCord C, Ozer T, Henry C (2021) Synthesis and grafting of diazonium tosylates for thermoplastic electrode immunosensors. Anal Methods 13:5056–5064

  30. Ozer T, Henry CS (2022) All-solid-state potassium-selective sensor based on carbon black modified thermoplastic electrode. Electrochimica Acta 404:139762

  31. Ozer T, McMahon C, Henry CS (2020) Advances in paper-based analytical devices. Annu Rev Anal Chem 13:85–109

    Article  Google Scholar 

  32. Kudo H et al (2020) Microfluidic paper-based analytical devices for colorimetric detection of lactoferrin. SLAS TECHNOLOGY: Translating Life Sciences Innovation 25(1):47–57

    Article  CAS  Google Scholar 

  33. Katoh A et al (2020) All-printed semiquantitative paper-based analytical devices relying on QR code array readout. Analyst 145(18):6071–6078

    Article  CAS  PubMed  Google Scholar 

  34. Soda Y et al (2018) Selective detection of K+ by ion-selective optode nanoparticles on cellulosic filter paper substrates. ACS Applied Nano Materials 1(4):1792–1800

    Article  CAS  Google Scholar 

  35. Ozer T, Henry CS (2021) Based analytical devices for virus detection: recent strategies for current and future pandemics. TrAC Trends Anal Chem 144:116424

  36. Noviana E et al (2021) Microfluidic paper-based analytical devices: from design to applications. Chem Rev 121(19):11835–11885

  37. Rasmi Y et al (2021) Emerging point-of-care biosensors for rapid diagnosis of COVID-19: current progress, challenges, and future prospects. Anal Bioanal Chem 413(16):4137–4159

  38. Ozer T, Henry CS (2021) Recent advances in sensor arrays for the simultaneous electrochemical detection of multiple analytes. J Electrochem Soc 168(5):057507

  39. McCord CP, Summers B, Henry CS (2021) Redox behavior and surface morphology of polystyrene thermoplastic electrodes. Electrochimica Acta 393:139069

    Article  CAS  Google Scholar 

  40. Cinti S et al (2018) Low-cost and reagent-free paper-based device to detect chloride ions in serum and sweat. Talanta 179:186–192

    Article  CAS  PubMed  Google Scholar 

  41. Pradela-Filho LA et al (2020) Rapid analysis in continuous-flow electrochemical paper-based analytical devices. ACS sensors 5(1):274–281

    Article  CAS  PubMed  Google Scholar 

  42. Ding J et al (2016) A Three-dimensional origami paper-based device for potentiometric biosensing. Angew Chem Int Ed 55(42):13033–13037

    Article  CAS  Google Scholar 

  43. Gao W et al (2020) A Solid-state reference electrode based on a self-referencing pulstrode. Angew Chem Int Ed 59(6):2294–2298

    Article  CAS  Google Scholar 

  44. Bakker E, Pretsch E, Bühlmann P (2000) Selectivity of potentiometric ion sensors. Anal Chem 72(6):1127–1133

    Article  CAS  PubMed  Google Scholar 

  45. Mazzaracchio V et al (2021) All-solid state ion-selective carbon black-modified printed electrode for sodium detection in sweat. Electrochimica Acta 394:139050

    Article  CAS  Google Scholar 

  46. Bobacka J (1999) Potential stability of all-solid-state ion-selective electrodes using conducting polymers as ion-to-electron transducers. Anal Chem 71(21):4932–4937

    Article  CAS  PubMed  Google Scholar 

  47. Ocaña C et al (2018) Calcium-selective electrodes based on photo-cured polyurethane-acrylate membranes covalently attached to methacrylate functionalized poly (3, 4-ethylenedioxythiophene) as solid-contact. Talanta 186:279–285

    Article  PubMed  CAS  Google Scholar 

  48. Portet C, Yushin G, Gogotsi Y (2008) Effect of carbon particle size on electrochemical performance of EDLC. J Electrochem Soc 155(7):A531

    Article  CAS  Google Scholar 

  49. Arduini F et al (2020) Carbon black as an outstanding and affordable nanomaterial for electrochemical (bio) sensor design. Biosensors and Bioelectronics 156:112033

    Article  CAS  PubMed  Google Scholar 

  50. Bandodkar AJ et al (2014) Epidermal tattoo potentiometric sodium sensors with wireless signal transduction for continuous non-invasive sweat monitoring. Biosens Bioelectron 54:603–609

    Article  CAS  PubMed  Google Scholar 

  51. Ali TA, Abd-Elaal AA, Mohamed GG (2021) Screen printed ion selective electrodes based on self-assembled thiol surfactant-gold-nanoparticles for determination of Cu (II) in different water samples. Microchemical Journal 160:105693

    Article  CAS  Google Scholar 

  52. Nägele M et al (1998) Influence of lipophilic inert electrolytes on the selectivity of polymer membrane electrodes. Anal Chem 70(9):1686–1691

    Article  PubMed  Google Scholar 

  53. McNaught AD, Wilkinson A (1997) Compendium of chemical terminology. Blackwell Science Oxford 1669

  54. Harvey CJ, LeBouf RF, Stefaniak AB (2010) Formulation and stability of a novel artificial human sweat under conditions of storage and use. Toxicol In Vitro 24(6):1790–1796

    Article  CAS  PubMed  Google Scholar 

  55. Rose DP et al (2014) Adhesive RFID sensor patch for monitoring of sweat electrolytes. IEEE Trans Biomed Eng 62(6):1457–1465

    Article  PubMed  Google Scholar 

  56. da Silva ETSGN et al (2014) Simple on-plastic/paper inkjet-printed solid-state Ag/AgCl pseudoreference electrode. Anal Chem 86(21):10531–10534

    Article  PubMed  CAS  Google Scholar 

  57. Guinovart T et al (2014) A reference electrode based on polyvinyl butyral (PVB) polymer for decentralized chemical measurements. Anal Chim Acta 821:72–80

    Article  CAS  PubMed  Google Scholar 

  58. Mousavi Z et al (2013) An analytical quality solid-state composite reference electrode. Analyst 138(18):5216–5220

    Article  CAS  PubMed  Google Scholar 

  59. Mazzaracchio V et al (2021) All-solid state ion-selective carbon black-modified printed electrode for sodium detection in sweat. Electrochimica Acta 394:139050

  60. Ping J et al (2013) High-performance flexible potentiometric sensing devices using free-standing graphene paper. Journal of Materials Chemistry B 1(37):4781–4791

    Article  CAS  PubMed  Google Scholar 

  61. Miguel-Hidalgo JJ et al (2010) Glial and glutamatergic markers in depression, alcoholism, and their comorbidity. J Affect Disord 127(1–3):230–240

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Bieg C, Fuchsberger K, Stelzle M (2017) Introduction to polymer-based solid-contact ion-selective electrodes—basic concepts, practical considerations, and current research topics. Anal Bioanal Chem 409(1):45–61

    Article  CAS  PubMed  Google Scholar 

  63. Pięk M et al (2018) Molecular organic materials intermediate layers modified with carbon black in potentiometric sensors for chloride determination. Electrochim Acta 283:1753–1762

    Article  CAS  Google Scholar 

  64. Howard G (1988) Measurement of sodium and potassium in clinical chemistry. A review Analyst 113(3):373–384

    Article  Google Scholar 

  65. Byrne C et al (2021) Serum potassium and mortality in high-risk patients: SPRINT. Hypertension, HYPERTENSIONAHA 78(5):1586–1594

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Acknowledgements

The authors would like to thank Dr. Ismail Agir for providing the custom-made potentiometer with its software for potentiometric measurements.

Funding

This work was financially supported by the National Science Foundation (CHE-1710222). Additional support was provided by Colorado State University.

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Correspondence to Charles S. Henry.

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Ozer, T., Henry, C.S. Microfluidic-based ion-selective thermoplastic electrode array for point-of-care detection of potassium and sodium ions. Microchim Acta 189, 152 (2022). https://doi.org/10.1007/s00604-022-05264-y

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