A sensor system for nanoparticles' safety assessment
The EU-funded project INSTANT (Innovative sensor for the fast analysis of nanoparticles in selected target products) changed this status quo with a cost-effective, point-of-need, integrated device for the detection and quantification of ENPs in complex samples such as food and cosmetics. Scientists selected and produced different ENP species with varied properties for analysis: silver, gold, zinc oxide and titanium oxide. Samples tested included foods, juices and sunscreens containing these ENPs. INSTANT researchers optimised and standardised sample preparation techniques to enable good ENP extraction, detection and identification. A major success is the development of a generalised extraction protocol. The consortium developed and tested the utility of molecularly imprinted polymers (MIPs) and tailored carbon nanotubes (tCNTs) as sensing material. These were incorporated into recognition elements to create robust sensor arrays that are capable of label-free optical and electrochemical sensing for physicochemical characterisation of ENPs. Their sensing unit also combines advanced fluidics with a modular and easy to use flow-cell, facilitating parallel read-out with both optical and electrochemical detection strategies on one transducer. This innovative set-up permits the simultaneous detection of different ENP species. Scientists incorporated the sample preparation, sensing and electronic supply units into two prototypes for on-site and in-lab operation. Only functionalised tCNTs were selected for prototype performance assessment using real samples. MIP integration proved too laborious during the project period. Prototypes also incorporated process software for chemometric evaluation as well as communications and graphical user interfaces. Results were validated in a round-robin approach and researchers upgraded the INSTANT demonstrator components to further optimise performance. Project outcomes were widely disseminated via several publications, conferences, press releases, fairs and exhibitions as well as audio/video materials. At first, the INSTANT team has successfully delivered a fully integrated and validated cost-effective device to monitor and analyse ENPs that are present in cosmetic products, food and drinks. Such devices can be used for developing evidence-based safety regulations to ensure explicit labelling of products. Other applications include sensors for detecting toxic particles or pathogens in the environment. Besides increasing the competitiveness of the consortium, end users will also benefit by increased consumer confidence in the safety of products with ENPs.
Keywords
Sensor, safety, engineered nanoparticle, INSTANT, extraction protocol, molecularly imprinted polymers, tailored carbon nanotubes, prototype
