DEONoS Project

Title: Development of Dual Electrical/Optical NanoSensors on Flexible Substrates by Colloidal Self-Assembly

Code: PN-II-RU-TE-2011-3-0134

Contract. no. 36/ 05.10.2011

Value: 900000 Lei

Duration: 01.11.2011 - 31.10.2014

Acknowledgement: This work was supported by a grant of the Romanian National Authority for Scientifc Research, CNCS –UEFISCDI, project number PN-II-RU-TE-2011-3-0134.

Members: Dr. Cosmin Farcau (Project Director), Prof. Dr. Simion Astilean, Dr. Monica Potara, Dr. Sanda Boca-Farcau (Boca), PhD Cosmin Leordean.

Summary: The project titled Development of Dual Electrical/Optical NanoSensors on Flexible Substrates by Colloidal Self-Assembly proposes to develop highly efficient nanoparticle-based (bio)chemo-sensors with simultaneous optical and electrical readout. Colloidal gold nanoparticles (<100 nm) will be synthesized and imparted with specific chemical function. Nanoparticle films of controlled morphology (2D or 3D, planar or wire-like) and compact packing will be obtained by Convective Self-Assembly (CSA) on flexible/stretchable substrates. The optical/plasmonic and electrical properties, the surface enhanced Raman Scattering (SERS) efficiency, and their inter-dependence will be investigated in order to optimize these nanoparticle assemblies as dual electric/optical sensors (DEOS) for bio-chemo-detection. The flexible substrate will allow to modify interparticle plasmon couplings and electron tunneling barriers and optimize the sensor's sensitivity. The electric, chemiresistor 'half' of the DEOS will transduce molecular adsorbtion events in a resistance change, while by simultaneous SERS analyses the adsorbed species will be identified based on its vibrational fingerprint. This will make the DEOS an innovative sensor that will outperform both electrical and optical existing sensors. This project will also contribute to multiply the skills and knowledge of their young members by their involvement in a challenging endeavour of scientific actuality within the broader field of nanotechnology.

Main results:

- gold and silver nanoparticles (NPs) were synthesized and functionalized with Bis(p-sulfonatophenyl)phenilphosphine dihydrate dipotasium;

- a computer-controlled home-made Convective Self-Assembly (CSA) setup was realized, which is fully functional and was used for the preparation of nanoparticle films;

- Au NPs were assembled by CSA into films on both rigid glass and flexible polycarbonate substrates;

- we demonstrated that these NP films make efficient and uniform SERS substrates for biomolecular sensing;

- electrically conductive nanoparticle film strips on Si substrate were realized;

- periodically patterned Au NP films were realized by Binary CSA of nano- and micro- colloids; these exhibit an additional SERS enhancement due to photonic/ diffractive coupling;

- Au NP films were self-assembled on commercially available interdigitated electrodes (IDE), showing the compatibility of the technique with commercial products

- the NP films on IDEs were demonstrated to be efficient dual electric and optical (SERS-based) sensors

Details on these results, in correlation with the proposed objectives, can be found in the activity report attached below.


1. C. Farcau, N. M. Sangeetha, N. Decorde, S. Astilean, L. Ressier, Microarrays of gold nanoparticle clusters fabricated by Stop&Go convective self-assembly for SERS-based sensor chips, Nanoscale 2012, 4, 7870. (IF 6.23)

2. C. Farcau, M. Potara, C. Leordean, S. Boca, S. Astilean, Reliable plasmonic substrates for bioanalytical SERS applications easily prepared by colloidal assembly of gold nanocolloids, Analyst 2013, 138, 546. (IF 3.90)

3. V. Saracut, M. Giloan, M. Gabor, S. Astilean, C. Farcau, Polarization-sensitive linear plasmonic nanostructures via colloidal lithography with uniaxial colloidal arrays, ACS Applied Materials & Interfaces 2013, 5, 1362. highlighted on the journal cover (IF 5.90)

4. C. Leordean, M. Potara, S. Boca-Farcau, A. Vulpoi, S. Astilean, C. Farcau, Multiscale Electromagnetic SERS Enhancement on Self-Assembled Micro-Patterned Gold Nanoparticle Films, J. Raman Spectr. 2014, 45, 627. (IF 2.51)

5. C. Farcau, S. Astilean, Periodically Nanostructured Substrates for Surface Enhanced Raman Spectroscopy, J. Mol. Struct. 2014, 1073, 102 (IF 1.59)

6. S. Boca, C. Leordean, S. Astilean, C. Farcau, Chemiresistive / SERS Dual Sensor Based on Densely-Packed Gold Nanoparticles, Beilstein J. Nanotechnol. 2015, 6, 2498.


C. Farcau, S. Boca, C. Leordean, M. Potara, V. Saracut, L. Ressier, S. Astilean, Substrates for plasmon-enhanced optical spectroscopies via convective assembly of nano- and micro-particles, 31st European Congress on Molecular Spectroscopy EUCMOS 26-31 August 2012, Cluj-Napoca, Romania.

C. Farcau, C. Leordean, M. Potara, S. Boca-Farcau, S. Astilean, Multiscale Electromagnetic Enhancement in Colloidal Gold Nanoparticle Films with Periodic Hole Array Made by Binary Convective Self-Assembly, 10th International Conference on Nanosciences & Nanotechnologies (NN13), 9-12 July 2013, Thessaloniki, Greece.

A. Sabau, C. Leordean, M. Potara, S. Boca-Farcau, C. Farcau, S. Astilean, Fabrication of electrically conductive plasmonic stripe arrays through Stop&Go Convective Self-Assembly of gold nanoparticles, 5th Conference on Advanced Spectroscopies on Biomedical and Nanostructured Systems (BioNanoSpec), September 7-10, 2014, Cluj-Napoca, Romania.

C. Farcau, S. Boca-Farcau, R. Vallee, S. Astilean, Polarized SERS on Ag Film over Nanosphere Linear Arrays, Surface Enhanced Spectroscopies 2014, Chemnitz Germany, 7-10 Aug.

C. Leordean, M. Potara, S. Boca-Farcau, S. Astilean, C. Farcau. Self-assembled micro-patterned colloidal gold nanoparticle films as reliable SERS substrates, Surface Enhanced Spectroscopies 2014, Chemnitz Germany, 7-10 Aug.

last update: 24.11.2014