Bimodal instrumentation for Biomolecular Detection and Identification by Nano-Enhanced Plasmonic Imaging and Raman Analysis – PIRANEX

This project addresses the issue of investigating, both theoretically and experimentally, and taking advantage of the unique optical properties of gold nanostructures for the design of new photonics and more precisely plasmonics devices. Indeed, such nanostructures, after proper biofunctionalization into biochips, will be inserted into an optical instrument for the purpose of enhanced sensor systems. In order to increase the performances of such a platform and make a breakthrough in this technology, the project proposes to demonstrate that it is possible to take advantage simultaneously, in a bimodal optical instrument, of both the sensitivity enhancement than can be obtained for surface plasmonic resonance imaging (SPRI) as well as surface enhanced Raman scattering (SERS) systems. In such an instrument, the biochip would be analysed both:
-by SPRI whose parallel imaging capability will provide label-free detection and quantification of bio-target binding in real-time and with high throughput,
-by SERS which will be used to analyse only those areas of interest as directed by the SPRI data and whose spectral signatures will provide unambiguous identification of the captured bio-targets.
Modelling of the electromagnetic field in the complex metallo-dielectric structures will be performed using efficient in-laboratory made codes, providing accurate and optimized nanostructures, while being reasonable in calculation time and computer requirements. These calculations will be conducted in order to optimize the SPRI sensing capabilities as well as the SERS spectroscopic analysis by modelling the electromagnetic field enhancement provided by the nanostructures, taking progressively into account the details of the real structures. Using optimised optical properties and geometrical parameters (size, shape and in-plane arrangement) of the nanostructures, we will be able to design a highly sensitive nanosensor.
The real structures will be produced firstly through e-beam lithography, to experimentally demonstrate the structural properties on micronic to millimetric scales, and secondly using nano-imprint techniques, to demonstrate the feasibility of the production of these nanostructures on a large surface, from millimetric to centimetric scales, and at low cost and yet reasonable quality as required for routine usage.
Chemical functionalization will address the issue of transforming these structured substrates into biochips. Taking advantage of the efficient structures in terms of sensing will require precise localization of the biomolecular probes, in particular either using orthogonal chemistries onto SiO2 masked Au substrates or using self-assembled monolayer density changes around the structure angular areas.
A bimodal instrument prototype including SPRI and SERS detection will be industrially developed. Demonstration of the capability of this new nano-enhanced bimodal optical instrument will be done on important societal and market applications ranging from medical diagnosis to food safety. Model cases will include protein biochips for cancer early diagnosis and biological and environmental food contaminants.
To achieve such objectives, a well-balanced academic, industrial and end-users consortium has been brought together. It is composed of the (Nano-)BioPhotonics groups from Institut d’Optique, Palaiseau, and from the “Chemistry Structures and Properties of Biomaterials and Therapeutic Agents” of “University Paris Nord”, as well as the Institut d’Electronique Fondamentale of Université Paris Sud and Institut des NanoTechnologies de Lyon – all four academics being CNRS laboratories. The industrial partner, Horiba Jobin Yvon, is a world key player in analytical systems. The validation of the envisioned bimodal instrumental system, providing both plasmon imaging and Raman analysis, will be demonstrated by an end-user club, involving many public hospitals (APHPs and CHUs) as well as French agri-food pole of excellence AgroParisTech.