Struktūra

Nanotechnologijų skyrius

Skyrius vadovas prof., habil.. dr. Arūnas Ramanavičius  
tel. +370 5 2619532
 

Nanotechnologijų skyriuje vykdomi plataus spektro tyrimai biologinių jutiklių srityje. 

Viena iš šių sričių tai optinių biologinių jutiklių kūrimas. Šiam tikslui naudojamos spektrinės elipsometrijos, paviršiaus plazmonų rezonanso, taip pat spektrinės elipsometrijos sustiprintos paviršiaus plazmonų rezonansu metodikos. Tyrimų metu nustatomos įvairių padėklų, skirtų naudoti biologiniams jutikliams optinės savybės. Šiam tikslui naudojami skirtingi padėklai tokie kaip nanolaminatai, sudaryti iš pasikartojančių metalų oksidų bisluoksnių, turinčių skirtingą storį. Parenkant reikiamą bisluoksnių skaičių ir atskirų sluoksnių storius galima gauti optiniams jutikliams reikalingas dangas, pasižyminčias konkrečiomis optinėmis savybėmis. Nanolaminatuose yra naudojamos tokios medžiagos kaip Al2O3/ZnO, Al2O3/TiO2, ZnO/GOx bisluoksniai. Taip pat optiniams biologiniams jutikliams kurti naudojamos nanovielų, suformuotų iš ZnO ir TiO2 dangos, ar metalų sluoksniai, skirti sužadinti paviršines plazmonines bangas. Atlikus reikiamus padėklų tyrimus toliau jie yra modifikuojami biologiniais sluoksniais, suformuojamais iš skirtingų baltymų ar fermentų. Naudojant spektrinės elipsometrijos metodiką realiu laiku galima analizuoti šių sluoksnių formavimosi kinetiką. Išmatavus kinetiką toliau yra taikomi įvairūs analitiniai ir skaitmeniniai modeliavimo metodai, skirti suskaičiuoti kinetinius parametrus ir atskleisti molekulinių sluoksnių formavimosi mechanizmus bei jų sąveikas su kitais baltymais. 

Kita Nanotechnologijų skyriuje atliekamų tyrimų tema yra elektrocheminiai tyrimai kaip tyrimo objektus taikant elektrai laidžius polimerus. Tyrimams yra naudojami tokie elektrai laidūs polimerai kaip polipirolas (Ppy) ir jo dariniai, polianilinas (PANI) ir jo dariniai, poli(3, 4-etilenodioksitiofenas) (PEDOT). Taip pat tiriami kopolimerai gauti elektrochemiškai polimerizuojant minėtus monomerus. Pagrindinės šių polimerų tyrimų kryptys yra elektrochrominių savybių tyrimai, molekulių įspaudų polimerų pritaikymas gaminant jutiklius mažamolekulinių junginių nustatymui tirpaluose ir t.t. 

Nanotechnologijų skyriuje kuriamos ir analizuojamos kelių skirtingų tipų biokuro elementų sistemos. Daugiausia dėmesio skiriame fermentinėms (gliukozės oksidazės, krienų peroksidazės pagrindu) ir mikroorganizmų (mielių, aerobinių ir anaerobinių bakterijų pagrindu) biokuro elementų sistemoms, veikiančiomis vienos arba kelių kamerų konfigūracijose. Su tikslu panaudoti energijos produkcijai ir atliekų valymui. 


SKYRIAUS DARBUOTOJŲ PASIEKIMAI, APDOVANOJIMAI
  • Dr Ieva Plikusiene, Biosensors 2021 Early-career Women award, MDPI, Basel 2022.
  • Dr Ieva Plikusiene has been recognized as 2022 L‘Oréal-Unesco international rising talent (https://www.unesco.org/en/prizes/women-science/)
  • 2022 m. spalio 14, įvyko tarptautinė mokslinė konferencija Chemistry and Chemical Technologies 2022, kurioje Vincento Mindaugo Mačiulio žodinis pranešimas „Study of SARS-CoV-2 nucleocapsid protein and specific antibodies interaction by combined optical and acoustic methods” buvo apdovanotas kaip geriausias žodinis pranešimas (Best oral presentation (Biochemistry and enviromental chemistry) (https://cct-conference.ktu.edu).
  • 2022 m. spalio 19 – 20 d. įvyko 12-ji Fizinių ir technologijos mokslų centro (FTMC) doktorantų ir jaunųjų mokslininkų konferencija FizTech2022, kurioje Raimondos Bogužaitės „Electrochemical Deposition and Modifications of Polypyrrole with Methylene Blue“ ir Vincento Mindaugo Mačiulio „SARS-CoV-2 nucleocapsid protein immune complex investigation by combined acoustic and optical methods“ žodiniai pranešimai Geriausių žodinių pranešimų nugalėtojais (https://www.ftmc.lt/news/1192/69/Doktorantu-ir-jaunuju-mokslininku-konferencija-FizTech2022).
Svarbiausios publikacijos
  1. Ramanavičius, Simonas; Samukaitė-Bubnienė, Urtė; Ratautaitė, Vilma; Bechelany, Mikhael; Ramanavičius, Arūnas. Electrochemical molecularly imprinted polymer based sensors for pharmaceutical and biomedical applications (review) // Journal of pharmaceutical and biomedical analysis. ISSN 0731-7085. 2022, vol. 215, art. no. 114739, p. 1-12.
  2. Drobysh, Maryia; Liustrovaitė, Viktorija; Baradokė, Aušra; Viter, Roman; Chen, Chien-Fu; Ramanavičius, Arūnas; Ramanavičienė, Almira. Determination of rSpike protein by specific antibodies with screen-printed carbon electrode modified by electrodeposited gold nanostructures // Biosensors. eISSN 2079-6374. 2022, vol. 12, no. 8, art. no. 593, p. 1-16.
  3. Šlekienė, Nora; Snitka, Valentinas; Bružaitė, Ingrida; Ramanavičius, Arūnas. Influence of TiO2 and ZnO nanoparticles on α-Synuclein and β-Amyloid aggregation and formation of protein fibrils // Materials. ISSN 1996-1944. 2022, vol. 15, iss. 21, art. no. 7664, p. 1-18.
  4. Andriukonis, Eivydas; Reinikovaitė, Viktorija; Ramanavičius, Arūnas. Comparative study of polydopamine and polypyrrole modified yeast cells applied in biofuel cell design // Sustainable energy and fuels. ISSN 2398-4902. 2022, vol. 6, iss. 18, p. 4209-4217.
  5. Dronina, Julija; Plaušinaitis, Deivis; Samukaitė-Bubnienė, Urtė; Ramanavičius, Arūnas. Real-time label-free assessment of T7 DNA polymerase immobilization // Materials today nano. ISSN 2588-8420. 2022, vol. 19, art. no. 100232, p. 1-8.
  6. Ratautaitė, Vilma; Brazys, Ernestas; Ramanavičienė, Almira; Ramanavičius, Arūnas. Electrochemical sensors based on l-tryptophan molecularly imprinted polypyrrole and polyaniline // Journal of electroanalytical chemistry. ISSN 1572-6657. 2022, vol. 917, art. no. 116389, p. 1-10.
  7. Poderytė, Margarita; Valiūnienė, Aušra; Ramanavičius, Arūnas. Scanning electrochemical microscope as a tool for the electroporation of living yeast cells // Biosensors and bioelectronics. ISSN 0956-5663.  2022, vol. 205, art. no. 114096, p. 1-8.
  8. Plikusienė, Ieva; Mačiulis, Vincentas Mindaugas; Ramanavičius, Arūnas; Ramanavičienė, Almira. Spectroscopic ellipsometry and quartz crystal microbalance with dissipation for the assessment of polymer layers and for the application in biosensing // Polymers. eISSN 2073-4360. 2022, vol. 14, no. 5, art. no. 1056, p. 1-21.
  9. Dronina, Julija; Samukaitė-Bubnienė, Urtė; Ramanavičius, Arūnas. Towards application of CRISPR-Cas12a in the design of modern viral DNA detection tools (Review) // Journal of nanobiotechnology. ISSN 1477-3155. 2022, vol. 20, art. no. 41, p. 1-15.
  10. Balčiūnas, Domas; Plaušinaitis, Deivis; Ratautaitė, Vilma; Ramanavičienė, Almira; Ramanavičius, Arūnas. Towards electrochemical surface plasmon resonance sensor based on the molecularly imprinted polypyrrole for glyphosate sensing // Talanta. ISSN 0039-9140. 2022, vol. 241, art. no. 123252, p. 1-11.
  11. Samukaitė-Bubnienė, Urtė; Ratautaitė, Vilma; Ramanavičius, Arūnas; Bučinskas, Vytautas. Conducting polymers for the design of tactile sens // Polymers. eISSN 2073-4360. 2022, vol. 14, iss. 15, art. no. 2984, p. 1-20.
  12. Plikusienė, Ieva; Mačiulis, Vincentas; Juciutė, Silvija; Maciulevičienė, Rūta; Balevičius, Saulius; Ramanavičius, Arūnas; Ramanavičienė, Almira. Investigation and comparison of specific antibodies' affinity interaction with SARS-CoV-2 wild-type, B.1.1.7, and B.1.351 spike protein by total internal reflection ellipsometry // Biosensors. ISSN 2079-6374. 2022, vol. 12, iss. 5, art. no. 351, p. 1-12.
  13. Batiuskaite, Danute; Bruzaite, Ingrida; Snitka, Valentinas; Ramanavicius, Arunas. Assessment of TiO2 nanoparticle impact on surface morphology of Chinese hamster ovary cells // Materials. ISSN 1996-1944. 2022, vol. 15, iss. 13, art. no. 4570, p. 1-13.
  14. Liustrovaitė, Viktorija; Drobysh, Maryia; Ručinskienė, Alma; Baradokė, Aušra; Ramanavičienė, Almira; Plikusienė, Ieva; Samukaitė-Bubnienė, Urtė; Viter, Roman; Chen, Chien-Fu; Ramanavičius, Arūnas. Towards an electrochemical immunosensor for the detection of antibodies against SARS-CoV-2 spike protein // Journal of The Electrochemical Society. ISSN 0013-4651. 2022, vol. 169, iss. 3, art. no. 037523, p. 1-7.
  15. Plikusienė, Ieva; Mačiulis, Vincentas Mindaugas; Juciutė, Silvija; Ramanavičius, Arūnas; Balevičius, Zigmas; Slibinskas, Rimantas; Kučinskaitė-Kodzė, Indrė; Simanavičius, Martynas; Balevičius, Saulius; Ramanavičienė, Almira. Investigation of SARS-CoV-2 nucleocapsid protein interaction with a specific antibody by combined spectroscopic ellipsometry and quartz crystal microbalance with dissipation // Journal of colloid and interface science. ISSN 0021-9797. 2022, vol. 626, p. 113-122.
  16. Bužavaitė-Vertelienė, Ernesta; Mačiulis, Vincentas Mindaugas; Anulytė, Justina; Tolenis, Tomas; Baškys, Algirdas; Plikusienė, Ieva; Balevičius, Zigmas. Total internal reflection ellipsometry approach for bloch surface waves biosensing applications // Biosensors. ISSN 2079-6374. 2022, vol. 12, iss. 8, art. no. 584.
  17. Žalnėravičius, Rokas; Ramanavičius, Arūnas. Enhancement of glucose oxidase-based bioanode performance by comprising Spirulina platensis microalgae lysate // Journal of the electrochemical society. ISSN 0013-4651. 2022, vol. 169, iss. 5, art. no. 053510, p. 1-9.
  18. Žalnėravičius, Rokas; Klimas, Vaclovas; Naujokaitis, Arnas; Jagminas, Arūnas; Ramanavičius, Arūnas. Development of biofuel cell based on anode modified by glucose oxidase, Spirulina platensis-based lysate and multi-walled carbon nanotubes // Electrochimica acta. ISSN 0013-4686. 2022, vol. 426, art. no. 140689, p. 1-11.
  19. Drobysh, Maryia; Liustrovaitė, Viktorija; Baradokė, Aušra; Ručinskienė, Alma; Ramanavičienė, Almira; Ratautaitė, Vilma; Viter, Roman; Chen, Chien-Fu; Plikusienė, Ieva; Samukaitė-Bubnienė, Urtė; Slibinskas, Rimantas; Čiplys, Evaldas; Simanavičius, Martynas; Žvirblienė, Aurelija; Kučinskaitė-Kodzė, Indrė; Ramanavičius, Arūnas. Electrochemical determination of interaction between SARS-CoV-2 spike protein and specific antibodies // International Journal of Molecular Sciences. ISSN 1661-6596. 2022, vol. 23, iss. 12, art. no. 6768, p. 1-10.
  20. Badokas, Kazimieras; Kadys, Arūnas; Augulis, Dominykas; Mickevičius, Jūras; Ignatjev, Ilja; Skapas, Martynas; Šebeka, Benjaminas; Juška, Giedrius; Malinauskas, Tadas. MOVPE growth of GaN via graphene layers on GaN/sapphire templates // Nanomaterials. ISSN 2079-4991. 2022, vol. 12, iss. 5, art. no. 785, p. 1-10.
  21. Drobysh, Maryia; Ramanavičienė, Almira; Viter, Roman; Chen, Chien-Fu; Samukaitė-Bubnienė, Urtė; Ratautaitė, Vilma; Ramanavičius, Arūnas. Biosensors for the determination of SARS-CoV-2 virus and diagnosis of COVID-19 infection // International journal of molecular sciences. ISSN 1422-0067. 2022, vol. 23, iss. 2, art. no. 666, p. 1-28.
  22. Ratautaitė, Vilma; Bogužaitė, Raimonda; Brazys, Ernestas; Ramanavičienė, Almira; Čiplys, Evaldas; Juozapaitis, Mindaugas; Slibinskas, Rimantas; Bechelany, Mikhael; Ramanavičius, Arūnas. Molecularly imprinted polypyrrole based sensor for the detection of SARS-CoV-2 spike glycoprotein // Electrochimica acta. ISSN 0013-4686. 2022, vol. 403, art. no. 139581, p. 1-7.
  23. Ramanavičius, Simonas; Morkvėnaitė-Vilkončienė, Inga; Samukaitė-Bubnienė, Urtė; Ratautaitė, Vilma; Plikusienė, Ieva; Viter, Roman; Ramanavičius, Arūnas. Electrochemically deposited molecularly imprinted polymer-based sensors // Sensors. ISSN 1424-8220. 2022, vol. 22, iss. 3, art. no. 1282, p. 1-22.
  24. Zinovičius, Antanas; Rožėnė, Justė; Merkelis, Timas; Bružaitė, Ingrida; Ramanavičius, Arūnas; Morkvėnaitė-Vilkončienė, Inga. Evaluation of a yeast–polypyrrole biocomposite used in microbial fuel cells. Sensors // eISSN 1424-8220. 2022, vol. 22, iss.1, art. no. 327, p. 1-12.
  25. Žalnėravičius, Rokas; Paškevičius, Algimantas; Samukaitė-Bubnienė, Urtė; Ramanavičius, Simonas; Vilkienė, Monika; Mockevičienė, Ieva; Ramanavičius, Arūnas. Microbial fuel cell based on nitrogen-fixing Rhizobium anhuiense bacteria // Biosensors. eISSN 2079-6374. 2022, vol. 12, iss. 2, art. no. 113, p. 1-15.
  26. Petrulevičienė, Milda; Juodkazytė, Jurga; Savickaja, Irena; Karpič, Renata; Morkvėnaitė-Vilkončienė, Inga; Ramanavičius, Arūnas. BiVO4-based coatings for non-enzymatic photoelectrochemical glucose determination // Journal of electroanalytical chemistry. ISSN 1572-6657. 2022, vol. 918, art. no. 116446, p. 1-28.
2022 M. STRAIPSNIŲ APŽVALGA
Spectroscopic Ellipsometry and Quartz Crystal Microbalance with Dissipation for the Assessment of Polymer Layers and for the Application in the Biosensing

I. Plikusiene, V. Maciulis, A. Ramanavicius, A. Ramanaviciene, Spectroscopic Ellipsometry and Quartz Crystal Microbalance with Dissipation for the Assessment of Polymer Layers and for the Application in Biosensing, Polymers, 14 (2022) 1056. https://doi.org/10.3390/polym14051056

Polymers represent materials that are applied in almost all areas of modern life, therefore, the characterization of polymer layers using different methods is of great importance. In this review, the main attention is dedicated to the non-invasive and label-free optical and acoustic methods, namely spectroscopic ellipsometry (SE) and quartz crystal microbalance with dissipation (QCM-D). The specific advantages of these techniques applied for in situ monitoring of polymer layer formation and characterization, biomolecule immobilization, and registration of specific interactions were summarized and discussed.


Figure 1. Scheme of optical Spectroscopic Ellipsometry and acoustic Quartz Crystal Microbalance with Dissipation signals detection in presence of a thin polymer layer on top of the sensor.

 
Real-time label-free assessment of T7 DNA polymerase immobilization
J. Dronina, D. Plausinaitis, U. Samukaite-Bubniene, A. Ramanavicius, Real-time label-free assessment of T7 DNA polymerase immobilization, Materials Today Nano, 19 (2022) 100232. https://doi.org/10.1016/j.mtnano.2022.100232
Immobilization of DNA-modifying enzymes on any surface is still a complex and challenging task in biotechnology and biosensorics. Therefore, this task very often is crucial, especially in biosensors dedicated to the continuous monitoring of DNA. The novelty and the importance of this study are related to the development of continuously operating biosensors based on DNA-modifying enzymes. In this research, we focused on the real-time monitoring of T7 DNA polymerase immobilization. Quartz crystal microbalance (QCM) was applied for the monitoring of immobilization of T7 DNA polymerase and assessment of analytical signals generated during the action of this enzyme.



Figure 2. Scheme of the time-resolved simultaneous measurement of changes in frequency, energy dissipation, and surface saturation by T7 DNA polymerase during the immobilization process on the Quartz Crystal Microbalance sensor.

 
Determination of rSpike Protein by Specific Antibodies with Screen-Printed Carbon Electrode Modified by Electrodeposited Gold Nanostructures

M. Drobysh, V. Liustrovaite, A. Baradoke, R. Viter, C.-F. Chen, A. Ramanavicius, A. Ramanaviciene, Determination of rSpike Protein by Specific Antibodies with Screen-Printed Carbon Electrode Modified by Electrodeposited Gold Nanostructures, Biosensors, 12 (2022) 593. https://doi.org/10.3390/bios12080593
The applicability of electrochemical sensing techniques for detecting specific antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins in the blood serum of patient samples following coronavirus disease 2019 (COVID-19) was assessed. Herein, screen-printed carbon electrodes (SPCE) with electrodeposited gold nanostructures (AuNS) were modified with L-Cysteine for further covalent immobilization of recombinant SARS-CoV-2 spike proteins (rSpike). The affinity interactions of the rSpike protein with specific antibodies against this protein (anti-rSpike) were assessed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods.

 

Figure 3. Scheme of experimental stages occurring on the SPCE. (1): The formation of SPCE/AuNS by electrodeposition; (2): SPCE/AuNS/SAM formation; (3): the activation of the SPCE/AuNS/SAM by EDC-NHS mixture following SPCE/AuNS/SAM/rSpike formation; (4): ethanolamine blocking of remaining active functional groups and SPCE/AuNS/SAM/rSpike/anti-rSpike immunocomplex formation via the interaction between immobilized rSpike protein and the anti-rSpike antibodies present in the aliquot. 

 
Towards an Electrochemical Immunosensor for the Detection of Antibodies against SARS-CoV-2 Spike Protein

V. Liustrovaite, M. Drobysh, A. Rucinskiene, A. Baradoke, A. Ramanaviciene, I. Plikusiene, U. Samukaite-Bubniene, R. Viter, C.-F. Chen, A. Ramanavicius, Towards an Electrochemical Immunosensor for the Detection of Antibodies against SARS-CoV-2 Spike Protein, Journal of The Electrochemical Society, 169 (2022) 037523. https://doi.org/10.1149/1945-7111/ac5d91
The electrochemical system for the detection of specific antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins in blood serum patient samples after coronavirus disease 2019 (COVID-19). For this purpose, the recombinant SARS-CoV-2 spike protein (SCoV2-rS) was covalently immobilized on the surface of the gold electrode pre-modified with the mixed self-assembled monolayer (SAMmix) consisting of 11-mercaptoundecanoic acid and 6-mercapto-1-hexanol. The affinity interaction of SCoV2-rS with specific antibodies against this protein (anti-rS) was detected using two electrochemical methods: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).



Figure 4. Scheme of experimental stages: (1) SAMmix layer formation on Au electrode (Au/SAMmix); (2) SAMmix activation by EDC-NHS mixture (Au/SAMmix/EDC-NHS); (3) SCoV2-rS immobilisation and formation of Au/SAMmix/SCoV2-rS sensing structure; (4) BSA binding of remaining activated carboxyl groups; (5) affinity interaction of anti-rS with immobilised SCoV2-rS (Au/SAMmix/SCoV2-rS/anti-rS).

 
Molecularly Imprinted Polypyrrole-based Sensor for the Detection of SARS-CoV-2 Spike Glycoprotein

V. Ratautaite, R. Boguzaite, E. Brazys, A. Ramanaviciene, E. Ciplys, M. Juozapaitis, R. Slibinskas, M. Bechelany, A. Ramanavicius, Molecularly Imprinted Polypyrrole based Sensor for the Detection of SARS-CoV-2 Spike Glycoprotein, Electrochimica Acta, 403 (2022) 139581. https://doi.org/10.1016/j.electacta.2021.139581
The application of a polypyrrole-based sensor for the determination of SARS-CoV-2-S spike glycoprotein is described. The electrochemical sensor was designed by molecular imprinting of polypyrrole (Ppy) with SARS-CoV-2-S spike glycoprotein (MIP-Ppy). The electrochemical sensors with MIP-Ppy and with polypyrrole without imprints (NIP-Ppy) layers were electrochemically deposited on a platinum electrode surface by a sequence of potential pulses. The performance of polymer layers was evaluated by pulsed amperometric detection.


Figure 5. Scheme of evaluation by chronoamperometry of Pt electrode modified with non-imprinted polypyrrole (NIP-Ppy) and with molecularly imprinted polypyrrole (MIP-Ppy) with SARS-CoV-2-S glycoprotein imprints. Electrochemical measurements were performed in phosphate-buffered saline (PBS) solution, pH 7.4.

 
Electrochemical sensors based on L-tryptophan molecularly imprinted polypyrrole and polyaniline

V. Ratautaite, E. Brazys, A. Ramanaviciene, A. Ramanavicius, Electrochemical Sensors based on L-Tryptophan Molecularly Imprinted Polypyrrole and Polyaniline, Journal of Electroanalytical Chemistry, 917 (2022) 116389. https://doi.org/10.1016/j.jelechem.2022.116389
The aim of this work was to compare two different conducting polymers (polypyrrole and polyaniline) in the design of the molecularly imprinted polymer (MIP). An l-tryptophan was selected as a template molecule in such MIP-based layers deposited on the graphite electrodes. Further, the MIPs with l-tryptophan imprints were applied in the design of electrochemical sensors for the detection of l-tryptophan. All polymer layers were electrochemically deposited on the electrode surface by the application of potential cycling. The characteristics of all modified electrodes were evaluated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The results demonstrate that the molecularly imprinted polypyrrole MIPpy layer has a greater affinity toward l-tryptophan molecules in comparison with other layers evaluated in this study.

Figure 6. Scheme of evaluation of graphite electrode modified with non-imprinted polypyrrole (NIP-Ppy) and with molecularly imprinted polypyrrole (MIP-Ppy) with l-tryptophan imprints. Electrochemical measurements were performed by differential pulse voltammetry in 40 mM BR buffer solution with 0.1 M of KCl, pH 2.5.

 
Evaluation of Electrochromic Properties of Polypyrrole/Poly(Methylene Blue) Layer Doped by Polysaccharides

V. Ratautaite, R. Boguzaite, M.B. Mickeviciute, L. Mikoliunaite, U. Samukaite-Bubniene, A. Ramanavicius, A. Ramanaviciene, Evaluation of Electrochromic Properties of Polypyrrole/Poly(Methylene Blue) Layer Doped by Polysaccharides, Sensors, 22 (2022) 232. https://doi.org/10.3390/s22010232
Polypyrrole (Ppy) and poly(methylene blue) (PMB) heterostructure (Ppy-PMB) was electrochemically formed on the indium tin oxide (ITO) coated glass slides, which served as working electrodes. For electropolymerization, a solution containing pyrrole, methylene blue, and a saccharide (lactose, sucrose, or heparin) that served as a dopant. The aim of this study was to compare the effect of the saccharides (lactose, sucrose, and heparin) on the electrochromic properties of the Ppy-PMB layer. Electrochromic properties were analyzed with respect to the changes in absorbance of the layer at two wavelengths (668 nm and 750 nm) by changing the pH of the surrounding solution and the potential between +0.8 V and −0.8 V.

 
Comparative study of polydopamine and polypyrrole modified yeast cells applied in biofuel cell design

E. Andriukonis, V. Reinikovaite, A. Ramanavicius, Comparative study of polydopamine and polypyrrole modified yeast cells applied in biofuel cell design, Sustainable Energy & Fuels, 6 (2022) 4209-4217. https://doi.org/10.1039/D2SE00634K
Due to high global energy requirements, the research for green-renewable energy has skyrocketed in the past few years. Yeast-based microbial fuel cells (MFC) could serve as a potential alternative energy source.

Redox-active polymers are currently featured as a promising new class of electron mediators with lower cytotoxicity compared to other conventional electron mediators. In this study, we tested two electroconductive polymers, polypyrrole (Ppy) and polydopamine (PDA), which possess good electrical properties and are biocompatible with microorganisms.

Both PDA and Ppy modifications are deemed successful, which is indicated by an increase in the charge transfer from the yeast cells to the electrodes. Overall, our modifications applied shorter incubation times in the polymerization bulk solution and generated a greater electric current of approximately a 5-fold power increase compared to the regular yeast MFCs.



Figure 7. Scheme of the assessment of polydopamine and polypyrrole-modified yeast cells used in the development of biofuel cells.

 
Development of biofuel cells based on anode modified by glucose oxidase, Spirulina platensis-based lysate and multi-walled carbon nanotubes

R. Žalnėravičius, V. Klimas, A. Naujokaitis, A. Jagminas, A. Ramanavičius, Development of biofuel cell based on anode modified by glucose oxidase, Spirulina platensis-based lysate and multi-walled carbon nanotubes, Electrochimica Acta, 426 (2022) 140689. https://doi.org/10.1016/j.electacta.2022.140689
Bioanode was successfully designed using the chemical oxidized multi-walled carbon nanotubes (CNT) and Spirulina platensis-based lysates that facilitate the electron transfer and reduce the open circuit potential (OCP) drop along the electron transfer pathway. Composition, morphology and chemical modification efficiency of CNT was examined using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and simultaneous thermal analysis (STA) coupled with mass spectrometric (MS) analysis of evolving gaseous species (TG/DTA–MS). The results of this study indicate that glucose oxidase (GOx) immobilized on CNT functionalized with S. platensis-based lysates possess superior electron transfer and reduce the OCP drop along the electron transfer pathway.



Figure 8. Scheme of the bioanode consisting of glassy carbon with polyethyleneimine, multi-walled carbon nanotubes (CNT) and Spirulina platensis-based lysates and used for the development of biofuel cells.