title: Thermal independent silicon-nitride slot waveguide biosensor with high sensitivity.
abstract: As the sensitivity and detection limit of photonic refractive index (RI) biosensor increases, the temperature dependence becomes a major challenge. In this paper, we present a Mach-Zehnder Interferometer (MZI) biosensor based on silicon nitride slot waveguides. The biosensor is designed for minimal temperature dependence without compromising the performance in terms of sensitivity and detection limit. With air cladding, the measured surface sensitivity and detection limit of MZI biosensor reach 7.16 nm/(ng mm(-2)) and 1.30 (pg mm(-2)), while achieving a low temperature dependence is 5.0 pm/° C. With water cladding, the measured bulk sensitivity and detection limit reach 1730(2π)/RIU and 1.29 × 10(-5) RIU respectively. By utilizing Vernier effect through cascaded MZI structures, the measured sensitivity enhancement factor is 8.38, which results in a surface detection limit of 0.155 (pg mm(-2)).
authors.affiliation: Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore. tux@ime.a-star.edu.sg
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Tu
authors.forename: Junfeng
authors.initials: J
authors.lastname: Song
authors.forename: Tsung-Yang
authors.initials: TY
authors.lastname: Liow
authors.forename: Mi Kyoung
authors.initials: MK
authors.lastname: Park
authors.forename: Jessie Quah
authors.initials: JQ
authors.lastname: Yiying
authors.forename: Jack Sheng
authors.initials: JS
authors.lastname: Kee
authors.forename: Mingbin
authors.initials: M
authors.lastname: Yu
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Lo
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007368:Interferometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D017655:Silicon Compounds / Q000737:chemistry*; D013696:Temperature
chemical_list: D017655:Silicon Compounds; C032734:silicon nitride