- 25 April 2016
The proposed solution is a device consisting in a sensing chip and an optical reader. The sensing chip consists in an optically reflective substrate composed of areas with different surface properties. Each area is characterised by given values of the surface free energy components. Each area is composed of different smaller areas (sub-areas) characterised by an array of sub-micrometric holes. Each subarea is characterized by holes with different aperture size, S. Each sub-area is characterised by a particular optical response, when shined by a beam of visible light at a certain angle of incidence and polarization. As a results of the nano-grating, the incident light is diffracted at a given wavelength as a function depends of the refractive index of the hole containing or not the NMs. The presence of NMs in the holes can be thus monitored by measuring the wavelength of the diffracted light.
NMs in suspension or in a colloidal solution are characterised by the same triplet of values of the surface energy according to their surface properties. NMs flowed onto to the sensing chip by means of a liquid cell will be attracted by the respective areas. By this method the triplet of the NMs will be reconstructed according to the affinity of the NMs to the different areas with the corresponding surface properties.
THE MAIN APPLICATION AREAS
The constant increase of NMs present in consumer products and the high number of new nanomedicines based on NMs make urgent the need to develop new tools enabling rapid characterisation of NMs properties such as particular size, surface chemistry and hydrophobicity.
THE MAIN INNOVATIVE ASPECTS AND ADVANTAGES
The commercial/state-of-art characterization techniques enabling the NMs characterisation are multiple but there is no single method enabling the determination of the surface properties and the size distribution in one step. This new solution enables the rapid screening of a sample containing NMs. The sensor will enable the detection in a few seconds. Together with the minimum size, the device will characterise the surface property of the NMs, determining their acidic, basic o dispersive components.