Screen-Printed Hybrid Electrodes for Detecting and Monitoring Lipopolysaccharides TOXINSENS-255PED/2020

Project Partners and Institutions:

Project Director:

CS I. Dr. eng. Tanta-Verona IORDACHE, Leader of Team 1, Advanced Polymer Materials and Polymer Recycling Group, Polymers Department, INCDCP-ICECHIM

Coordinator:

National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Bucharest, Romania (www.icechim.ro)

Project Responsible:

Professor Dr. eng. Catalin ZAHARIA, Director of Department of Bioresources and Polymer Science, Faculty of Applied Chemistry and Material Science, Politehnica University of Bucharest,

Eng. Petru EPURE, Administrator at EPI-SISTEM S.R.L. Brasov,

Partners:·        

Politehnica University of Bucharest, www.upb.ro·        

EPI-SISTEM S.R.L. Brasov, www.epi.ro      

National Funding Agencies

Unitatea executiva pentru finantarea invatamantului superior, a cercetarii, dezvoltarii  si inovarii (UEFISCDI)

https://www.uefiscdi.ro/UEFISCDI contract no. 255PED/2020;

UEFISCDI Contract budget: 600 000 RON

EPI-SISTEM Brasov Romania, www.epi.ro: 36 000 RON

Duration of project: 24 months (start date:03 August 2020)

Abstract

The project TOXINSENS refers to dsigning innovative, versatile and re-usable biosensors for the fast,qualitative and quantitative detection and monitoring of popolysaccharides(LPS- endotoxin derived from Gram-negative bacteria, GNB) in various biological, food or water samples. For this matter, a medium consortium was created taking into account the project interdisciplinary and complexity, which includes the Project Coordinator ICECHIM that owns the background of the Concept approached in this project proposal, a Partner with state-of-the art facilities for characterisation i.e. UPB and a SME Partner-EPI SISTEM SRL capable of testing the project prototypes, adsorbing the know-how of manufacturing and commercialise the resulted LPS-biosensors. The project on-set refers to the following bioinspired concept: Methodology for the preparation of LPS-sensitive films-TRL 2. The concept was originally proposed by the Project Leader and developed within the Advanced Polymer Materials & Polymer Recycling Group from ICECHIM on project TE123/2018 BACTERIOSENS. Starting from this point, TOXINSENS targets first the upgrade of this former concept by addition of electro-active nanoparticles to the precursor films solution. In this way, an electro-active hybrid paste will be generated and used to print LPS-hybrid films directly on blank ceramic electrodes (TRL 3). The prepared LPS-Screen-printed hybrid electrodes will be further tested in laboratory -relevant environments and the innovative technologies will be thus validated (TRL 4). The specific output of the project will lead to several outcomes during project implementation (short-term scenario: at least 3 publications, 3 communications at prestigious Symposia or Congresses and 1 patent claim), and also after project end long-term scenario: research and development roadmaps, performance data, transferable knowledge).

Objective

The project general objective targets the use of the scientific fundamental background generated on Project TE123/2018 (which is the only knowledge available at this moment at national and international level) to move to a higher level of technological maturity (demonstrator and laboratory validated technology). In this way, the capacity to generate validated solutions in the laboratory for significantly improved products (i.e. the LPS-Screen-printed hybrid electrodes), know-how (for the LPS electro-active hybrid paste and for the adjusted 3D printing methodologies) and preparation technologies (for the LPS-Screen-printed hybrid electrodes) of the involved RT&D Organizations (ICECHIM and UPB) will be enhanced and the SME partner (EPI SISTEM) will be the first to benefit of these solutions.

Estimated Results

(1) Precursor solutions for LPS-hybrid films and Preparation Methodologies; (2) Intermediary Product Sheet; (3) LPS-hybrid films and Preparation Methodologies; (4) adapted 3D Printing Methodologies; (5)Test Performance Report of LPS-hybrid films; (6) Product Sheet; (7) LPS-Hybrid Biosensor Prototypes and Preparation Methodologies; (8) Test Performance Report for the LPS-Hybrid Biosensor Prototypes; (9) LPS-Hybrid Biosensors; (10) Preparation Laboratory Technology for the LPS-Hybrid Biosensors; (11)DEMO Report for the functionality of LPS-Hybrid Biosensors; (12)Three conference paper communications; (13) Scientific papers, 3 ISI papers sent for publication; (14) Specific Website of the project “TOXINSENS”; (15) Patent Application on the design and preparation of LPS-screen printed hybrid electrodes.

Acknowledgement:

Project Partners would like to thank UEFISCDI for sustaining and funding the research activity performed in TOXINSENS project.

Project Staff

Team Staff from INCDCP-ICECHIM

Team Staff from Politehnica University of Bucharest (P1)

Team Staff from EPI-SISTEM S.R.L. (P2)

PHASE I: THE OBTAINING OF PRECURSOR SOLUTIONS FOR HYBRID FILMS PRYNTING

PHASE PERIOD: 03.08-31.12.2020

OBJECTIVE

Activity 1.1 Preparation of the precursor solutions for hybrid films (Responsible: EPI SISTEM, ICECHIM)

Activity 1.1.1 Studies on the required specifications for the preparation of the electroactive precusor paste (viscosity and thermal stability) and on the establishment of a commercial reference

Activity1.1.2 Preparation of precursor solutions for hybrid films with electroactive nanoparticles (carbon or metal oxides) to obtain a printable paste

Activity 1.2 Physico-chemical characterizations of the precursors (Responsabili: UPB, ICECHIM)

Activity 1.2.1 Morphological and structural characterization of the raw materials by SEM/microCT, XPS/DLS and the determination of thermal stability (TGA/DTG, DSC) of the precursor solutions.

Activity 1.2.2 FTIR structural characterization and determination of viscosity (Rheometry) of precursor solutions

Activity 1.3 Communication and dissemination of results at national or international conferences and publication of papers in journals indexed by the web of science

Activity 1.3.1 Communication and dissemination activities of the results

Activity 1.3.2 Communication and dissemination activities of the results

SUMMARY

In Stage I/2020 the partner EPI-SISTEM S.R.L. presents the studies regarding the necessary specifications for the preparation of precursor electroactive paste (viscosity and thermal stability) and the establishment of a commercial reference. In this regard, in order to make a small serie of screen printed electrodes, 3 procedures will be approached: classic screen printing, inkjet printing and 3D printing. A screen-printed electrode model (screen-printed masks on A5 formats) was made and high-temperature-resistant substrate types such as polyimide, Kapton, fiberglass-reinforced silicone were prepared. A commercial reference and the technical specifications that the electroactive material must fulfill in order to be printed in optimal conditions, for preparing the screen-printed electrodes for detecting lipopolyssacharides, was established.

ICECHIM coordinator successfully prepared several series of molecularly imprinted particles with LPS and the control non-imprinted ones by sol-gel technique, using several stabilizers. The precursor solutions for hybrid films with electroactive nanoparticles in the form of printable paste were prepared using in this first stage both particle types, imprinted with LPS and non-imprinted. The recipe for preparing the precursor solutions was in good accordance with the properties that the electroactive material must fulfill in order to be printed on the screen-printed electrodes by EPI-SISTEM Partner.

ICECHIM together with UPB Partner performed physico-chemical characterizations of the precursors by FTIR spectroscopic analyzes, BET porosimetry, morphological-dimensional DLS, thermal TGA / DTG, UV-Vis spectrometric and determination of the viscosity of the precursor solutions. The FTIR spectra of all synthesized particles and electroactive precursors confirmed the presence of the LPS template in the matrix, by characteristic vibrations of OH (ν-OH) bonds belonging to phosphate groups and glucosamine molecules recorded in the region 3450-3200 cm-1 (intense wide band). The dynamic light diffusion (DLS) analysis revealed a narrow polydispersity and a monomodal distribution in the range of 500-600 nm for the LPS imprinted polymer particles. For the reference samples (without LPS template) unstable dispersions could be observed, with formation of aggregates and bimodal distributions. N2 adsorption-desorption isotherms have shown to be type IV according to IUPAC, with a hysteresis curve characteristic of mesoporous structures. BET analysis showed that both the specific surfaces and the surface areas and volumes of pores are significantly larger for the MIP imprinted particles compared to those of the control particles. The thermal decomposition mechanism of the

imprinted polymers differs from that of the non-imprinted polymers due to the presence of LPS, with higher mass losses in the case of MIP. MIP particles are slightly more stable (due to LPS-matrix interactions) and more homogeneous than NIP homologous.

The electroactive precursor solutions with LPS imprinted particles and non-imprinted particles showed a pseudo-plastic flow in the range of low shear gradients (0-100 s-1) and a quasi-Newtonian at higher shear gradients (100-1300 s-1). The most appropriate rheological behavior for a reference solution for printing hybrid pastes on electrodes was concluded to be the closest to Newtonian.

DISSEMINATION

Scientific communications:

1. Elena-Bianca Stoica, Ana-Mihaela Gavrila, Andrei Sarbu, Andreea Miron, Marius Ghiurea, Bogdan Trica, Valentin Raditoiu, Razvan Botez, Iulia Elena Neblea, Tanta-Verona Iordache, Electrochemical sensor based on molecularly imprinted polymers for lipopolisaccharides detection, PRIOCHEM XVI, 28-30 Octomber 2020, Bucharest, Romania (oral communication).

Articles:

1. Bianca Elena Stoica, Ana-Mihaela Gavrila, Andrei Sarbu, Horia Iovu, Hugues Brisset, Andreea Miron, Tanta-Verona Iordache, Uncovering the behaviour of carbon screen printed electrodes modified with lipopolysaccharide-molecularly imprinted polymers, trimis spre publicare Electrochemistry Communication, revizie majora (IF = 4.333)


2. Ana-Mihaela Gavrila, Simona Nedelcu-Flor, Andrei Sarbu, Teodor Sandu, Andreea Olaru, Gheorghe Hubca, Dan Donescu, Tanta-Verona Iordache, Synthesis and properties of organosilica particles with quaternary ammonium bearings as bacteriostatic interfaces, trimis spre publicare U.P.B. Scientific Bulletin 2020, ISSN 1223-7027.

In order to support the activity of dissemination, EPI SISTEM Partner has created a web page http://www.tehnoadvice.ro/toxinsens.html where the summary of the 2020 stage will be presented.


PHASE

II: 3D PRINTING OF HYBRID FILMS AND THEIR TRANSPOSITION ON

SCREEN PRINTED ELECTRODES

PHASE

PERIOD: 01.01-31.12.2021

OBJECTIVE

Activity

2.1 Hybrid film printing by 3D technique on plain plastic or ceramic (Responsible: EPI SISTEM, ICECHIM)

Activity 2.1.1 Printing films based on electroactive nanoparticles by 3D technique on plastic or ceramic support

Activity 2.1.2 Study of the adhesion, time and maturation temperature of hybrid films deposited on plastic/ ceramic support

Activity 2.2 Physico-chemical characterizations of the hybrid films (Responsible: UPB, ICECHIM)

Activity 2.2.1 Morphological (SEM / microCT), structural (XPS, FTIR) characterization, contact angle measurements and thermal analysis (TGA / DTG, DSC) of hybrid films

Activity 2.2.2 Determination of LPS specificity of hybrid films (static adsorption via UV-vis)

Activity 2.3 Hybrid films printing by 3D technique on electrodes to obtain Hybrid Biosensors (Responsible: EPI SISTEM, ICECHIM)

Activity 2.3.1 Printing films based on electroactive nanoparticles by 3D technique on electrodes

Activity 2.3.2 Hybrid film optimization in terms of electrode sensitivity for LPS (cyclic voltammetry)


Activity 2.4 Physico-chemical characterizations of hybrid biosensor (Responsible: UPB, ICECHIM)

Activity 2.4.1 Study of films reproducibility by morphological (SEM / microCT), structural (XPS / FTIR) characterization and contact angle measurements of hybrid films deposited on electrodes

Activity 2.4.2 Study of films reproducibility by specificity measurements for LPS (cyclic voltammetry) of hybrid films deposited on electrodes


Activity 2.5 Communication and dissemination of results through national or international conferences (Responsible: ICECHIM, EPI SISTEM)

Activity 2.5.1 Communication and dissemination activities of the results

Activity 2.5.2 Communication and dissemination activities of the results

SUMMARY

           In Stage II/2021, the 3D printing of hybrid films and their transposition on screen-printed electrodes is described. This main objective includes (i) Reproducibility of hybrid film preparation containing electroactive nanoparticles with printable paste and physico-chemical characterization (ii) Hybrid films printing by 3D technique on plain plastic or ceramic support and morpho-structural and thermal characterization (iii) Determination of specificity for LPS of hybrid films (static adsorption via UV-vis) (iv) Hybrid films printing by 3D technique on electrodes to obtain Hybrid Biosensors and physico-chemical characterization (v) electrochemical characterization of hybrid films for reproducibility by specificity measurements for LPS (cyclic voltammetry) of hybrid films deposited on electrodes.

ICECHIM coordinator has successfully prepared the precursor solutions for electroactive nanoparticle hybrid films (MIP-NPs) in printable paste form using as non-imprinted particles NIP VBTAC, NIP SDS, NIP CTAB and NIP BTAC and respectively imprinted particles with LPS, MIP VBTAC, MIP SDS, MIP

CTAB and MIP BTAC. Micro and nanoparticles were synthesized by sol-gel technique, using several stabilizers: benzyl triethylammonium chloride (BTAC), vinyl benzyl-trimethylammonium chloride (VBTAC), cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). The electroactive hybrid pastes were subsequently printed by EPI-SISTEM partner on the working electrode surface of a screen-printed sensor (SPCE), thus obtaining the molecularly imprinted hybrid sensors with LPS, noted MIP-NPs-SPCE.

EPI-SISTEM S.R.L. Partner presents the tests regarding the hybrid films printing by 3D technique on plain plastic support. The films made by ICECHIM can be printed in good condition on various types of substrates and retain their electroactive properties after drying. The printing is done with nozzles with an inner diameter of 0.4 mm in conditions in which the shape quality of the electrodes is kept in good shape. Basic functionality is maintained and LPS detection is not affected. EPI SISTEM Partner prepared several sets of functionalized electrodes for LPS detection, namely it printed 40-50 electrodes,

10-15 pieces of each functionalization variant: MIP BTAC, MIP CTAB, NIP BTAC and NIP CTAB.

ICECHIM coordinator together with UPB Partner performed physico-chemical characterizations of hybrid films by FTIR spectroscopic analysis, contact angle measurements, BET porosimetry, morphological-dimensional SEM and DLS, thermal TGA / DTG, determination of LPS specificity of hybrid films by UV-Vis spectroscopy. Scanning electron microscopy (SEM) for sol-gel particles revealed relatively porous spherical particles, less regular, grouped in micro / nanosphere aggregates, ranging in size from a few hundred nanometers to a few microns, for both MIPs and NIPs. The variation of the contact angle depending on the time for the imprinted MIP BTAC and MIP CTAB hybrid pastes and the non-imprinted ones NIP BTAC and NIP CTAB, respectively, on plastic support, demonstrated a hydrophilic character. Dimensional characterization trough dynamic light diffusion analysis (DLS) technique of imprinted particles with LPS MIP and non-imprinted NIP, respectively, led to relatively stable dispersions, with the formation of aggregates and mostly single-mode distributions. The N2 adsorption-desorption isotherms of the imprinted, non-imprinted and extracted particle systems have been shown to be type II with a type IV allure according to IUPAC, with a hysteresis curve characteristic of mesoporous structures. The thermal decomposition mechanisms of the imprinted polymers differ from those of the non-imprinted polymers due to the LPS presence, with higher mass losses in the case of MIPs. Re-adsorption tests were performed to investigate the specificity of MIP particles for LPS by static adsorption via UV-vis. In the case of CTAB and BTAC polymers, the highest adsorption values ​​were observed.

For the reproducibility of hybrid films, ICECHIM Coordinator together with UPB Partner performed physico-chemical characterizations of the hybrid films deposited on electrodes (biosensors) by FTIR spectroscopic analyzes, hybrid films contact angle measurements, SEM morphology of particles and biosensors, rheological characterization of hybrid films. FTIR analysis of the hybrid films deposited on the electrodes (MIP imprinted paste and NIP non-imprinted reference paste) confirmed the incorporation of MIP and NIP particles and zinc oxide in the polymer matrix as well as the presence of carbon paste. Rheological testing of MIP CTAB / NIP CTAB, MIP SDS / NIP SDS, MIP BTAC / NIP BTAC, MIP VBTAC / NIP VBTAC hybrid pastes and the reference paste led to a pseudo-plastic behavior with a Newtonian tendency to higher shear gradients of the reference paste similar to hybrid pastes with electroactive nanoparticles, which confirms the reproducibility of their optimal printing properties. The most efficient hybrid biosensors MIP/NIP BTAC-NPs-SPCE and MIP/NIP CTAB-NPs-SPCE were tested and characterized electrochemically by cyclic voltammetry to optimize the sensitivity for LPS. The electrochemical behavior of the MIP BTAC-NPs-SPCE and NIP BTAC-NPs-SPCE biosensors before and after the LPS addition, revealed that with the addition of LPS on the surface of the functionalized working electrode, the intensity of the oxidation current increases considerably due to a positive offset of the anodic peak potential.

In conclusion, hybrid biosensors both on ceramic substrate and printed on plastic support MIP/ NIP-NPs-SPCE electrochemically tested in the presence and absence of LPS template, proved to be reproducible, good results being obtained for both sensor systems based on of BTAC and CTAB.


DISSEMINATION

Scientific communications:

    

1.     Ana-Lorena Ciurlică, Ana-Mihaela Gavrilă, Catalin Zaharia, Ionut Cristian Radu, Bianca-Elena Stoica, Iulia Neblea, Andrei Sarbu, Horia Iovu, Tanta-Verona Iordache, Molecularly imprinted polymers for lipopolysaccharides recognition, Bucharest Polymer Conference (BPC), 2nd Edition, 9-11 June 2021, Bucharest, Romania (short oral communication)

2.     Ana-Lorena NEAGU, Ana-Mihaela GAVRILA, Petru EPURE, Bianca-Elena STOICA, Iulia Elena NEBLEA, Catalin ZAHARIA, Horia IOVU, Tanta-Verona IORDACHE, Hybrid Inkjet-Pritable Paste for Screen-Printed Electrodes, Simpozion international Prioritatile Chimiei pentru o Dezvoltare Durabila PRIOCHEM – editia XVII, 27- 29 Octombrie 2021, Bucuresti, Romania (Poster)

3.   Elena-Bianca STOICA, Iulia Elena NEBLEA, Elvira ALEXANDRESCU, Sabina Georgiana BURLACU, Catalin Ionut MIHAESCU, Andrei SARBU, Tanta-Verona IORDACHE, Ana-Mihaela GAVRILA, The development of a MIP-based sensor for electrochemical detection, International Scientific Conference “Applications of Chemistry in Nanosciences and Biomaterials Engineering -NanoBioMat 2021” for young researchers, 25-27 November 2021, Bucharest, Romania(oral communication)

4. 1st (June) and 2nd (December) Doctoral Reports, Ana-Lorena Ciurlica (Neagu) with the thesis title: BIOMIMETIC SENSORS OBTAINING BASED ON MOLECULAR IMPRINTED POLYMERS. Doctoral coordinator: Prof. Dr. Ing. Horia IOVU.


Articles :

1. B.E. Stoica, A.M. Gavrila, A. Sarbu, H. Iovu, H. Brisset, A. Miron, T.V. Iordachec, Uncovering the behavior of screen-printed carbon electrodes modified with polymers molecularly imprinted with lipopolysaccharide, Electrochemistry Communications 124, 106965, 2021; https://doi.org/10.1016/j.elecom.2021.106965 Sended 2020, Published 2021

2. A.M. Gavrila, S. Nedelcu-Flor, A. Sarbu, T. Sandu, A. Olaru, G. Hubca, D. Donescu, T.V. Iordachec, Synthesis and properties of organosilica particles with quaternary ammonium bearings as bacteriostatic interfaces, Scientific Bulletin of UPB Series B, vol 3, 2021, Sended 2020, Published 2021

3. A.M. Gavrila , I.C. Radu, H. Stroescu, A. Zaharia, B.E. Stoica, A.L. Ciurlica, T.V. Iordachec, A. Sarbu, Role of functional monomers upon the properties of bisphenol A molecularly imprinted silica films, Applied Sciences 2021, 11(7), 2956; https://doi.org/10.3390/app11072956 Sended 2020, Published 2021



To support the activity of dissemination results, EPI SISTEM Partner has created a web page http://www.tehnoadvice.ro/toxinsens.htm where the summary of the 2021 stage will be presented.