Ricerc@Sapienza

The many fundamental roto-vibrational resonances of chemical compounds result in strong absorption lines in the mid-infrared region (λ ∼ 2–20 μm). For this reason, mid-infrared spectroscopy plays a key role in label-free sensing, in particular, for chemical recognition, but often lacks the required sensitivity to probe small numbers of molecules. In this work, we propose a vibrational sensing scheme based on Bloch surface waves (BSWs) on 1D photonic crystals to increase the sensitivity of mid-infrared sensors. We report on the design and deposition of CaF2/ZnS 1D photonic crystals.

Optical biosensors based on one-dimensional photonic crystals sustaining Bloch surface waves are proposed to study antibody interactions and perform affinity studies. The presented approach utilizes two types of different antibodies anchored at the sensitive area of a photonic crystal-based biosensor. Such a strategy allows for creating two or more on-chip regions with different biochemical features as well as studying the binding kinetics of biomolecules in real time.

A combined label-free and fluorescence surface optical technique was used to quantify the mass deposited in binary biomolecular coatings. These coatings were constituted by fibronectin (FN), to stimulate endothelialization, and phosphorylcholine (PRC), for its hemocompatibility, which are two properties of relevance for cardiovascular applications. One-dimensional photonic crystals sustaining a Bloch surface wave were used to characterize different FN/PRC coatings deposited by a combination of adsorption and grafting processes.

We report on hybrid inorganic/organic one-dimensional photonic crystal biochips sustaining Bloch surface waves. The biochips were used, together with an optical platform operating in a label-free and fluorescence configuration simultaneously, to detect the cancer biomarker Angiopoietin 2 in a protein base buffer. The hybrid photonic crystals embed in their geometry a thin functionalization poly-acrylic acid layer deposited by plasma polymerization, which is used to immobilize a monoclonal antibody for highly specific biological recognition.

We report on the detection of an angiogenic molecule Vascular Endothelial Growth Factor (VEGF) in different biological matrices by means of a new integrated biosensing platform exploiting the properties of Bloch surface waves. The new platform takes advantage of a tandem configuration, in which both label-free and enhanced fluorescence detection are implemented. Specifically designed one dimensional photonic crystals were deposited directly on disposable and low cost plastic biochips.

Photonic crystal (PC)-enhanced fluorescence has been proposed as a novel tool for early disease detection in liquid biopsy. Photobleaching of the emitters has never been deeply investigated, although its cross section is expected to increase because of the large field intensity enhancement in PC. Herein, we report on the experimental investigation of the anisotropic effects arising when fluorescence excitation and emission are coupled to differently polarized modes of the same PC structure.

We report on the development of a biosensing platform that combines label-free and fluorescence based detection on
disposable Bloch surface wave biochips. This system is applied to the detection of the HER2-neu/ErbB2 clinical
biomarker related to breast cancer development. We first describe the design and fabrication of the BSW biochips as
well as the principle of operation of the optical reading instrument. Then, the approaches for surface functionalization

Understanding how a fluid flows at the boundaries when it is confined at the microscale/nanoscale is crucial for a broad range of engineering and biology applications. We propose an experimental technique based on Bloch surface waves sustained by a one-dimensional photonic crystal to evaluate the speed of the contact line, i.e., the triple junction separating three phases, in the low Reynold’s number regime, and with a nanometric resolution.

We report on the combined label-free/fluorescence use of one-dimensional photonic crystals to optimize cancer biomarker detection in complex biological media. The optimization of the assay working parameters permits us to maximize the final response of the biosensor. The detection approach utilizes a sandwich assay, in which one-dimensional photonic crystals sustaining Bloch surface waves are modified with monoclonal antibodies in order to guarantee high specificity during biological recognition.

Photonic crystal (PC) enhanced fluorescence has been proposed as a novel tool for early disease detection in a liquid biopsy format. However, photobleaching of the emitters has never been deeply investigated, although its cross section is expected to increase due to the large field intensity enhancement. Herein, we report on a comprehensive theoretical description of the stationary fluorescence emission of molecular emitters bound to the surface of a one-dimensional photonic crystal (1DPC) biosensor.