Servicio de Información Comunitario sobre Investigación y Desarrollo - CORDIS

Periodic Report Summary 3 - NANODETECTOR (Ultrasensitive plasmonic detection of single nanoparticles)

Project Context and Objectives:
The project was based on the new experimental phenomenon discovered recently by one of our project partners: single subwavelength size objects give rise to optical signals in surface plasmon resonance microscopy. This provides a unique possibility for ultrasensitive on-line detection of engineered nanoparticles treating the detection of each adsorbed to the sensor surface single nanoparticle separately. Within the project a development of the device for detection of nanoparticles and its application for a range of practically important engineered nanoparticles wss performed. This work included theoretical analysis of the new effect, development and optimization of main components of plasmonic microscope as well as of sophisticated software for effective image analyses and isolation of nanoparticle signals from background noise. Measurements were performed in aqueous media as well as in air. Several types of inorganic, plastic and protein nanoparticles were examined. At the final step of the project monitoring of nanoparticles in simple and complicated samples as well as for monitoring of workplaces and waste during production of inorganic and protein nanoparticles was perfomed.

Project Results:
It is characteristic for the work described in PR3 that by the beginning of this stage the development of main components of NANODETECTOR technology and software was completed, the final prototypes of the device were delivered to the project partners, and a training of coworkers of industrial partners of the project was performed.

Potential Impact:
This period was focused on extensive applications of the developed technology for different analytical tasks, on analysis of its limits and application potential. Numerous presentations of this technology in scientific meetings were performed not as a successfully developing scientific project but as a well working, novel and extremely powerful analytical technology which can be immediately applied for a number of practical purposes. The project was selected to the best ten projects for presentation in NanoForum2015 in Riga. The performed life demonstration of measurements of nanoparticles in real samples has led to a strong interest of the congress audience. Other dissemination events include a co-organization and active participation in the common public workshop in Brussel which was organized together with two other FP7 projects - SMARTNANO and INSTANT. During the reporting period, the project results were reported in 9 scientific conferences and in 7 papers, a number of further papers are in preparation and will be submitted within few month after the end of the project.
Development of theory of plasmonic detection of single nanoparticles was completed. A good agreement between the shapes of the images calculated images and experimentally observed images of single nanoparticles were obtained. The theoretical dependence of signal intensity on the refractive index of nanoparticles and on the size of nanoparticles were demonstrated to be very close to the obtained experimental data. The theory was extended to ensembles of nanoparticles.
Analysis of the performance of NANODETECTOR technology in gaseous phase was performed using: (i) direct application of the specially developed NANODETECTOR instrument for the measurements in gaseous phases; (ii) extraction of nanoparticles from air to water and subsequent application of the usual NANODECTOR instrument developed for aqueous media. Both techniques provide fast analysis of aerosols. In the case of direct measurements of nanoparticles in gaseous phase, an accumulation of nanoparticles on the sensor surface by application of electric field was used. An agreement between the measured value of the adsorption rate and theoretical prediction allows one to apply this technology for nanoparticles of known sizes without calibration. The technology can be used for quantitative analysis of number concentration of nanoparticles in gaseous media while the extraction technique provides semi-quantitative data with high sensitivity due to accumulation of extracted nanoparticles.
Influence of surface coating, pH and ionic strength on binding of nanoparticles to different surfaces was studied. Binding to smooth and rough surfaces was compared. Correlation between literature data on nanotoxicity of nanoparticles and their adsorption to biomimetic surfaces was analyzed.
Software for analysis of patterns of nanoparticles was developed. It was demonstrated that SPR images of nanoparticles form characteristic libraries which can be used for identification of size and material of nanoparticles, but also to distinguish adsorption and desorption of nanoparticles. Based on this idea, a number of new applications were developed. Recognition of characteristic images of nanoparticles was applied to improve analytical performance of NANODETECTOR technology in analysis of complex media. For example, within RoundRobin it was demonstrated, that the technique can be used in such complex media as wine, non-transparent fruit juice or diluted sunscreen. Tracking and mapping of single nanoparticles was developed, it allowed us to follow the fate of each single nanoparticle on the sensor surface (from totally) up to a million) and to visualize their movement, adsorption/desorption or electrochemically induced optical conversions. A combination of tracking with electrochemical dissolution of nanoparticles allowed us to distinguish materials of nanoparticles.
The technology was been transferred to industrial partners and was successfully applied in real industrial environment.
In conclusion, the results obtained by the consortium during the final project period have demonstrated that the NANODETECTOR-technology (high resolution SPR-microscopy in combination with an advanced image analysis) is a powerful analytical technique for real-time quantitative detection of nanoparticles in liquids as well as in gas media. The technology provides real-time and pretreatment free detection of nanoparticles in liquids at number concentration below 1000 nanoparticles per microliter for 10 seconds measurement time. This value is limited by the number of nanoparticles adsorbed to the sensor surface and therefore can be further improved by increase of the sensor area or detection time. The analysis can be performed also in very complex media, such as wine, juice or diluted sunscreen. The shape of the detected images provides information on the size and refractive index of nanoparticles. The technology can be combined with other analytical techniques. The developed combination of NANODETECTOR with electrochemical methods provides a possibility for electrochemical analysis of nanomaterials.
The results of the project have surpassed initial plans and expectations of the project participants. Already at the current stage of the development of NANODETECTOR technology, it is difficult to find another technique for detection and analysis of nanoparticles in complex media that provides a comparable analytical performance and so wide application possibilities. Themselves, the NANODETECTOR technology has also a strong potential for further development.

List of Websites:

Información relacionada

Documentos y publicaciones

Reported by

Síganos en: RSS Facebook Twitter YouTube Gestionado por la Oficina de Publicaciones de la UE Arriba