title: Optical microchip array biosensor for multiplexed detection of bio-hazardous agents.
abstract: An optical waveguide array biosensor suitable for rapid detection of multiple bio-hazardous agents is presented. SpectroSens™ optical microchip sensors contain multiple spatially-separated waveguide channels with integral high-precision Bragg gratings sensitive to changes in refractive-index; selective surface-functionalisation of discrete sensing channels with different antibodies as bio-recognition elements enables selective multi-analyte biological detection. Interactions between target antigens in the test sample and respective surface-immobilised antibodies result in localised changes in refractive-index; the biosensor response manifests as increases in wavelength of light reflected from specific sensing channels. Multiplexed, label-free detection of 8 different biological agents, encompassing bacterial spores, vegetative cells, viruses and proteinaceous toxins has been demonstrated in real-time. Selective detection of Bacillus atrophaeus (BG) spores, Escherichia coli cells, MS2 viruses and ovalbumin (OVA) protein (simulant bio-hazardous agents) was first demonstrated as proof-of-concept; subsequently, detection of Bacillus anthracis (BA) spores (UM23CL2 strain), Franciscella tularensis (FT) cells (live vaccine strain), Vaccinia viruses (heat-killed) and ricin toxin (bio-hazardous agents) was proven. Two optical microchip sensors, each comprising 8 sensing channels were packaged into a single disposable cartridge allowing simultaneous 16-channel data acquisition. The specific antibody deposition sequence used in this study enabled detection of either 4 simulants or 4 bio-hazardous agents using a single consumable. The final device, a culmination of the multidisciplinary convergence of the fields of biology, chemistry, optoelectronics and microfluidics, is man-portable and inherently robust. The performance characteristics of the SpectroSens™ technology platform highlight its potential for exploitation as a 'detect to warn/treat' biodetector in security and defence operations.
authors.affiliation: Stratophase Ltd., Romsey SO51 9DL, United Kingdom. devaki.bhatta@stratophase.com
authors.forename: D
authors.initials: D
authors.lastname: Bhatta
authors.forename: A A
authors.initials: AA
authors.lastname: Michel
authors.forename: M
authors.initials: M
authors.lastname: Marti Villalba
authors.forename: G D
authors.initials: GD
authors.lastname: Emmerson
authors.forename: I J G
authors.initials: IJ
authors.lastname: Sparrow
authors.forename: E A
authors.initials: EA
authors.lastname: Perkins
authors.forename: M B
authors.initials: MB
authors.lastname: McDonnell
authors.forename: R W
authors.initials: RW
authors.lastname: Ely
authors.forename: G A
authors.initials: GA
authors.lastname: Cartwright
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D045424:Complex Mixtures / Q000032:analysis*; D017076:Computer-Aided Design; D004209:Disposable Equipment; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015386:Hazardous Substances / Q000032:analysis*; D007118:Immunoassay / Q000295:instrumentation*; D046228:Microarray Analysis / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*
chemical_list: D045424:Complex Mixtures; D015386:Hazardous Substances