Improvement of antigen detection efficiency with the use of two-dimensional photonic crystal as a substrate

Dmitriy Dovzhenko,Igor Nabiev,Vladimir Terekhin,Kirill Vokhmincev,Alyona Sukhanova

doi:10.1088/1742-6596/784/1/012018

Abstract

Multiplex detection of different antigens in human serum in order to reveal diseases at the early stage is of interest nowadays. There are a lot of biosensors, which use the fluorescent labels for specific detection of analytes. For instance, common method for detection of antigens in human serum samples is enzyme-linked immunosorbent assay (ELISA). One of the most effective ways to improve the sensitivity of this detection method is the use of a substrate that could enhance the fluorescent signal and make it easier to collect. Two-dimensional (2D) photonic crystals are very suitable structures for these purposes because of the ability to enhance the luminescent signal, control the light propagation and perform the analysis directly on its surface. In our study we have calculated optimal parameters for 2D-dimensional photonic crystal consisting of the array of silicon nano-rods, fabricated such photonic crystal on a silicon substrate using reactive ion etching and showed the possibility of its efficient application as a substrate for ELISA detection of human cancer antigens.

Highlights

Photonic crystals (PhC) are widely used in many scientific areas nowadays including optoelectronics, photonics [1], gas sensing [2] and biosensing [3,4,5]
We have made a finite difference time-domain (FDTD) calculation of the optimal parameters for 2D PhC array made of silicon nanorods, fabricated photonic crystal with desired properties on a silicon substrate using electron beam lithography and reactive ion etching (BOSCH process) and have demonstrated the possibility of its efficient application as a substrate for enzyme-linked immunosorbent assay (ELISA) detection of human cancer antigens
Cavities, lattice periods and rod morphology for rod-type 2D photonic crystal have been tested in order to achieve a good mode confinement and wide enough photonic bandgap for TM polarization with the cavity eigenmode at 565 nm wavelength corresponding to the maximum of quantum dots (QDs) photoluminescence that have been used as fluorescent markers

Summary

Introduction

Photonic crystals (PhC) are widely used in many scientific areas nowadays including optoelectronics, photonics [1], gas sensing [2] and biosensing [3,4,5]. Thereby, weak coupling regime between the cavity of 2D photonic crystal and the luminophores embedded inside the PhC structure can be possible, and the luminescence inside the cavity could be enhanced [6] These properties make 2D PhCs appear to be the best compromise for application in biosensing, for example as a substrate for improvement of luminescence detection techniques. We have made a finite difference time-domain (FDTD) calculation of the optimal parameters for 2D PhC array made of silicon nanorods, fabricated photonic crystal with desired properties on a silicon substrate using electron beam lithography and reactive ion etching (BOSCH process) and have demonstrated the possibility of its efficient application as a substrate for ELISA detection of human cancer antigens

Materials and methods

Results and discussion

Conclusions