Porous silicon ring resonator for compact, high sensitivity biosensing applications

Abstract

A ring resonator is patterned on a porous silicon slab waveguide to produce a compact, high quality factor biosensor with a large internal surface area available for enhanced recognition of biological and chemical molecules. The porous nature of the ring resonator allows molecules to directly interact with the guided mode. Quality factors near 10,000 were measured for porous silicon ring resonators with a radius of 25 μm. A bulk detection sensitivity of 380 nm/RIU was measured upon exposure to salt water solutions. Specific detection of nucleic acid molecules was demonstrated with a surface detection sensitivity of 4 pm/nM.

An Innovative Straight Resonator Incorporating a Vertical Slot as an Efficient Bio-Chemical Sensor

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 / and 335 / for the fully filled and for the case of empty slot (a case arises when sensing liquid may not enter the slot region), respectively. A significant improvement can be observed of the proposed device sensitivity compared to the other devices reported earlier [3]- [10]. The dashed line also shows a linear shift of resonance wavelength (Δ ) when the PEWs are positioned at 300 away from both the end faces of the Si core strips.…”

“…As a result, a greater sensitivity has been observed, illustrated by the blue and the green dashed lines with slope 820 / and 683 / for filled and empty slot region, respectively. These values are much higher and shows a considerable improvement over the theoretically and experimentally investigated sensing devices reported so far [3]- [10]. Besides the spectral shift i.e.…”

“…Wang et al recently proposed an improved slot waveguide based Bragg sensors with sensitivity as high as 340 / around 1550 wavelength with the help of enhanced light matter interaction into the slotted region [9]. Recently, an improved bulk detection sensitivity (380 / ) of porous silicon ring resonator for biosensing applications has been reported by G. A. Rodrigues et al [10]. Other optical bio-chemical sensors have incorporated microdisk resonator [11], photonic crystal cavities [12], [13] and Mach-Zehnder interferometers [14], [15].…”

Optical Biosensing and Bioimaging With Porous Silicon and Silicon Quantum Dots (Invited Review)

“…The grating was realized with polymer (photoresist) by electron beam lithography on porous silicon surface. Similar to the grating-coupled sensor, a ring-patterned porous silicon waveguide was reported to detect nucleic acid molecules [80]. The resonance shift on transmission spectrum of the waveguide was used to quantify the attachment of nucleic acids on the modified surfaces with a high quality factor (up to 10,000 indicating high sensitivity).…”

Methods of Porous Silicon Parameters Control

“…Using isopropanol as a test analyte, a sensitivity of 13,000 rad/RIU-cm was reported. As another example of a PSi waveguiding platform, one may note the recent report of a ring resonator fabricated by RIE etching of a PSi planar waveguide, with a bulk detection sensitivity of 380 nm/RIU (Rodriguez et al 2015).…”