Last Advances in Silicon-Based Optical Biosensors

Abstract

We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies.

Keywords: label-free detection; photonic biosensors; silicon photonics; waveguide devices.

Figure 1

Evanescent wave detection principle.

Figure 2

Standard integrated MZI and interferometric output.

Figure 3

MZI with a slot waveguide as sensing arm, which is redrawn based on [30].

Figure 4

Response in a MZI sensor. (a) Standard interferometric signal; (b) Linear readout using a modulation system. Reprinted from [36] with permission of the Optical Society of America.

Figure 5

(a) LOC device based on BiMW, reprinted from [53] with permission of the Royal Society of Chemistry (b) Trimodal waveguide, reprinted from [55] with permission of the Optical Society of America.

Figure 6

Ring resonator biosensors. (a) Conventional ring resonator; (b) two cascade ring resonators based on the Vernier-effect, which is redrawn based on [69]; (c) coupled-resonator optical-waveguide (CROW) [72] with permission of the Nature Publishing Group, and (d) micro-disk resonator [75].

Figure 7

Transmitted (T) and reflected (R) power in a Photonic Crystal transducer [76], with permission of The Electromagnetics Academy. (a) Without any defect; (b) Applying a defect in the structure.

Figure 8

Advances in PCs biosensors. (a) Multiple hole defects (MHDs) [88], with permission of the Optical Society of America; (b) Transmission bandpass combined with PC sensor, with permission of the AIP Publishing LLC [90].