Label-Free Detection of Morpholino-DNA Hybridization Using a Silicon Photonics Suspended Slab Micro-Ring Resonator

In this study, deoxyribonucleic acid (DNA) hybridization was demonstrated using a suspended silicon photonics micro-ring resonator with 90 nm-thick slab and morpholino as the capture probe. Complementary DNA of various concentrations were tested achieving surface sensitivity 2.12 nm/nM, detection limit 250 pM, an intrinsic 36.9 pM. A bulk 98 nm/RIU $1.03\times 10^{-3}$ RIU also measured upon exposure to isopropanol/deionized water solutions. With these characteristics, nm ring sensor proved promising candidate for lab-on-a-chip bio-sensing applications.