title: Multiplexed specific label-free detection of NCI-H358 lung cancer cell line lysates with silicon based photonic crystal microcavity biosensors.
abstract: We experimentally demonstrate label-free photonic crystal (PC) microcavity biosensors in silicon-on-insulator (SOI) to detect the epithelial-mesenchymal transition (EMT) transcription factor, ZEB1, in minute volumes of sample. Multiplexed specific detection of ZEB1 in lysates from NCI-H358 lung cancer cells down to an estimated concentration of 2 cells per micro-liter is demonstrated. L13 photonic crystal microcavities, coupled to W1 photonic crystal waveguides, are employed in which resonances show high Q in the bio-ambient phosphate buffered saline (PBS). When the sensor surface is derivatized with a specific antibody, the binding of the corresponding antigen from a complex whole-cell lysate generates a change in refractive index in the vicinity of the photonic crystal microcavity, leading to a change in the resonance wavelength of the resonance modes of the photonic crystal microcavity. The shift in the resonance wavelength reveals the presence of the antigen. The sensor cavity has a surface area of ∼11μm(2). Multiplexed sensors permit simultaneous detection of many binding interactions with specific immobilized antibodies from the same bio-sample at the same instant of time. Specificity was demonstrated using a sandwich assay which further amplifies the detection sensitivity at low concentrations. The device represents a proof-of-concept demonstration of label-free, high throughput, multiplexed detection of cancer cells with specificity and sensitivity on a silicon chip platform.
authors.affiliation: Department of Electrical and Computer Engineering, University of Texas at Austin, 10100 Burnet Road, Bldg 160, Austin, TX 78758, USA. swapnajit.chakravarty@omegaoptics.com
authors.forename: Swapnajit
authors.initials: S
authors.lastname: Chakravarty
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Lai
authors.forename: Yi
authors.initials: Y
authors.lastname: Zou
authors.forename: Harry A
authors.initials: HA
authors.lastname: Drabkin
authors.forename: Robert M
authors.initials: RM
authors.lastname: Gemmill
authors.forename: George R
authors.initials: GR
authors.lastname: Simon
authors.forename: Steve H
authors.initials: SH
authors.lastname: Chin
authors.forename: Ray T
authors.initials: RT
authors.lastname: Chen
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D045744:Cell Line, Tumor; D003460:Crystallization; D004867:Equipment Design; D019544:Equipment Failure Analysis; D018398:Homeodomain Proteins / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D008904:Miniaturization; D012031:Refractometry / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry; D013194:Staining and Labeling; D014157:Transcription Factors / Q000032:analysis*; D000071799:Zinc Finger E-box-Binding Homeobox 1
chemical_list: D014408:Biomarkers, Tumor; D018398:Homeodomain Proteins; D014157:Transcription Factors; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1; D012825:Silicon