title: Rapid, sensitive, and multiplexed on-chip optical sensors for micro-gas chromatography.
abstract: We developed and characterized a rapid, sensitive and integrated optical vapor sensor array for micro-gas chromatography (μGC) applications. The sensor is based on the Fabry-Pérot (FP) interferometer formed by a micrometre-thin vapor-sensitive polymer layer coated on a silicon wafer. The thickness and the refractive index of the polymer vary in response to the vapor analyte, resulting in a change in the reflected intensity of the laser impinged on the sensor. In our study, four different polymers were coated on four wells pre-etched on a silicon wafer to form a spatially separated sensor array. A CMOS imager was employed to simultaneously monitor the polymers' response, thus enabling multiplexed detection of a vapor analyte passing through the GC column. A sub-second detection time was demonstrated. In addition, a sub-picogram detection limit was achieved, representing orders of magnitude improvement over the on-chip vapor sensors previously reported.
authors.affiliation: Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Karthik
authors.initials: K
authors.lastname: Reddy
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Guo
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Wonsuk
authors.initials: W
authors.lastname: Lee
authors.forename: Maung Kyaw Khaing
authors.initials: MK
authors.lastname: Oo
authors.forename: Xudong
authors.initials: X
authors.lastname: Fan
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D046228:Microarray Analysis; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D012825:Silicon / Q000737:chemistry; D013997:Time Factors
chemical_list: D011108:Polymers; D012825:Silicon