title: Slow light engineering for high Q high sensitivity photonic crystal microcavity biosensors in silicon.
abstract: Current trends in photonic crystal microcavity biosensors in silicon-on-insulator (SOI), that focus on small and smaller sensors have faced a bottleneck trying to balance two contradictory requirements of resonance quality factor and sensitivity. By simultaneous control of the radiation loss and optical mode volumes, we show that both requirements can be satisfied simultaneously. Microcavity sensors are designed in which resonances show highest Q ≈ 9300 in the bio-ambient phosphate buffered saline (PBS) as well as highest sensitivity among photonic crystal biosensors. We experimentally demonstrated mass sensitivity 8.8 atto-grams with sensitivity per unit area of 0.8 pg/mm(2). Highest sensitivity, irrespective of the dissociation constant K(d), is demonstrated among all existing label-free optical biosensors in silicon at the concentration of 0.1 μg/ml.
authors: Omega Optics Inc., 10306 Sausalito Drive, Austin, TX 78759, USA. swapnajit.chakravarty@omegaoptics.com
authors: Swapnajit
authors: S
authors: Chakravarty
authors: Yi
authors: Y
authors: Zou
authors: Wei-Cheng
authors: WC
authors: Lai
authors: Ray T
authors: RT
authors: Chen
mesh_terms: D000818:Animals; D000906:Antibodies / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003460:Crystallization; D004867:Equipment Design; D006801:Humans; D008027:Light; D055616:Microtechnology; D017785:Photons; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: D000906:Antibodies; D012965:Sodium Chloride; D012825:Silicon