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


National Research & Development Institute for Chemistry and Petrochemistry-ICECHIM, Bucharest, Romania (

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,


Politehnica University of Bucharest,·        

EPI-SISTEM S.R.L. Brasov,      

National Funding Agencies

Unitatea executiva pentru finantarea invatamantului superior, a cercetarii, dezvoltarii  si inovarii (UEFISCDI) contract no. 255PED/2020;

UEFISCDI Contract budget: 600 000 RON

EPI-SISTEM Brasov Romania, 36 000 RON

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


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).


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.


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 PERIOD: 03.08-31.12.2020


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


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.


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).


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 where the summary of the 2020 stage will be presented.