An integrated optical interferometric nanodevice based on silicon technology for biosensor applications

Abstract

Integrated optical sensors have become important in recent years since they are the only technology which allows the direct detection of biomolecular interactions. Moreover, silicon microelectronics technology allows mass production as well as the fabrication of nano-/macrosystems on the same platform by hybrid integration of sources, sensors, photodetectors and complementary metal-oxide semiconductor electronics.For the fabrication of an optical sensor nanodevice with an integrated Mach–Zehnder interferometric (MZI) configuration, the optical waveguides must have two main features: monomode behaviour and a high surface sensitivity. In this paper we present the development of a MZI sensor based on total internal reflection waveguides with nanometre dimensions. The aim is to use these sensors in environmental control to detect water pollutants by immunoassay techniques.

Efficient design and optimization of bio-photonic sensing cells (BICELLs) for label free biosensing

“…In the last expression r| 2 and r^3 are the complex Fresnel coefficients between boundaries and fi* is given by Eqs. (2)(3)(4)(5) where d 2 is the thickness of the second layer, k is the wavelength, n lt n 2 , k\, 1(2 are the real and imaginary parts of the refractive index of the first and second media and 6\, the incident angle.…”

“…In particular, detecting non-labeled analytes [1 ] have particular interest, mainly due to the simplicity of the sensing protocol, compared with labeled sensors. The most developed tools are based on surface plasmon resonance (SPR) principle broadly reported in the scientific literature [2] as well as interferometry, using for example Mach-Zehnder [3], ring resonator interferometers [4], Young interferometers [5], among many others [6] operating with a variety of waveguides for the sensing optical readout. The complexity of coupling the light from a fiber to these waveguides, and also for taking the bioanalyte to the sensing surface, by means of complex microfluidic circuit might be often considered to be a drawback, although promising results are continuously improving these typologies of biosensors.…”

Two-dimensional photonic crystal based sensor for pressure sensing

“…Based on above sensing mechanisms, the optical sensors have been designed and analyzed, using directional couplers [5], Mach-Zehnder interferometers [6], nano-ring resonators [4,[7][8][9][10][11][12], and micro-ring resonators [13,14] for different applications, reported in the literature. In the literature, PC/PCRR (photonic crystal ring resonator) based sensors were reported for chemical sensing, force and strain sensing [7][8][9][10][11][12], refractive index and gas sensing [15][16][17], dengue virus detection [18], pressure sensing [12,19,20], aqueous environment [21] and biosensing (proteins, avidins, BSA, DNA, etc.)…”

Optical planar waveguide for cell counting

“…[11][12][13] Typically, the sensing principal is a change in effective refractive index of the guided mode in the waveguide because of a change in refractive index of an overlying material. [14][15][16][17][18] We use the evanescent field to sense objects, such as metal-tagged cells. In our approach, visible light from a low-cost diode laser is sent through the planar waveguide and the intensity of the light can be measured upon output by an inexpensive photodetector.…”