Stratophase Ltd.

Romsey, United Kingdom

Stratophase Ltd.

Romsey, United Kingdom

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Patent
Stratophase Ltd. | Date: 2017-07-26

A method of controlling additive delivery during a bioreaction in a bioreactor comprises running a bioreaction in a bioreactor including adding additive into the bioreactor during spaced-apart feed events, where contents of the bioreactor equilibrate during a stabilisation period after a feed event; making in situ measurements of a bulk physical property of the bioreactor contents during the bioreaction to obtain process trend data; calculating a derivative of process trend data obtained over a measurement period beginning after a stabilisation period, the derivative being a metabolic rate index (MRI); and using the MRI to determine a time for starting a next feed event. A controller for a bioreactor and a bioreactor system are configured to operate according to the method.


Bhatta D.,Stratophase Ltd. | McDonnell M.B.,Defence Science and Technology Laboratories | Perkins E.,Defence Science and Technology Laboratories
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

A multi-channel optical microchip sensor system suitable for real-time, label-free detection of a wide range of biological agents is presented. SpectroSens™ chips containing multiple high-precision planar Bragg gratings are exploited as lowcost, robust refractive index sensors. Sensitivity to biological agents is conferred by functionalising individual sensing regions with different antibodies selected against numerous targets of interest. Antigen binding to the surfaceimmobilised antibodies results in localised changes in refractive index; upon laser-induced interrogation of the sensing region via optical fibres, these antibody-antigen interactions manifest as increases in wavelength of light reflected from the sensor chip. Real-time detection of multiple biological agents including bacterial cells/spores, viruses and toxins has been demonstrated. Further improvements to sensor performance including physical and chemical methods are also investigated. This multi-analyte capability highlights the potential use of this sensing technology in applications ranging from bio-hazard detection for defence purposes to point-of-care clinical diagnostics. © 2010 SPIE.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2009.3.8 | Award Amount: 3.63M | Year: 2010

The detection of chemical or biological substances increasingly appears as an essential concern in order to prevent human or animal health and security related problems. Present analytical techniques are expensive and often require highly specialized staff and infrastructures. The principal need is to perform screening tests, which can be carried out in non-specialized infrastructures, e.g. Point of Care, schools and field, before unambiguous identification in a specialized laboratory. There is thus a need to develop a new detection system that has low-cost and is portable but at the same time offers high sensitivity, selectivity and multi-analyte detection from a sample containing various components (e.g. blood, serum, saliva, etc.).\n\nThe objective of P3SENS is to design, fabricate and validate a multichannel (50 or more) polymer photonic crystal based label-free disposable biosensor allowing for a positive/negative detection scheme of ultra small concentrations of analytes in solution (< 1 ng/mL). The biosensor will be encapsulated in a specifically designed microfluidic system in order to deliver the sample to the multiple sensing zones. The design of the biochip will allow it to be easily inserted in a compact measurement platform, usable by non-specialized practitioners outside of specialized laboratories for carrying simultaneous multi-analyte detection, delivering real-time monitoring, and with an assay duration that will not exceed a few tens of minutes.\n\nThe photonic chip proposed in this project will be based on polymer Photonic Crystal (PhC) micro-cavities coupled into a planar waveguide optical distribution circuit. The photonic chip will be fabricated with available fabrication technologies - and with an emphasis on low cost substrates (polymer) and fabrication processes (nano-imprint lithography). More generally, P3SENS will push forward the development of low cost disposable biochips based on photonics.


Bhatta D.,Stratophase Ltd. | Stadden E.,Stratophase Ltd. | Hashem E.,Stratophase Ltd. | Sparrow I.J.G.,Stratophase Ltd. | Emmerson G.D.,Stratophase Ltd.
Journal of Immunological Methods | Year: 2010

A rapid, label-free optical biosensor system for sensitive monitoring of bio-molecular interactions in real-time is presented. SpectroSens™ sensor chips are based on integrated planar Bragg gratings sensitive to localised changes in refractive index. Bio-molecule recognition is imparted by functionalisation of the sensing surface with antibodies against targets of interest. In this study, antibodies against selected proteins were oriented with recombinant Protein A/G, which was covalently immobilised to the sensor chip via amine coupling to a glutaraldehyde-activated silane layer. Immunoassays for the detection of rabbit IgG and ovalbumin proteins as model antibody-antigen interaction systems were performed. Binding of complementary antigens to respective antibody-functionalised sensors manifested as changes in wavelength of light reflected from the optical sensors. Quantitative binding kinetics with detection sensitivities in the mid ng/ml range were obtained for both antigens using this planar, two-dimensional surface coating. Data presented demonstrate the suitability of SpectroSens™ sensors as a valuable tool in life science research and development for monitoring bio-specific interactions, protein concentration determination and antibody selection; the optical integration and analytical characteristics of these sensors suggest that they may find numerous applications in bio-pharmaceutical development and clinical diagnostics. © 2010 Elsevier B.V.


Bhatta D.,Stratophase Ltd. | Stadden E.,Stratophase Ltd. | Hashem E.,Stratophase Ltd. | Sparrow I.J.G.,Stratophase Ltd. | Emmerson G.D.,Stratophase Ltd.
Sensors and Actuators, B: Chemical | Year: 2010

A universal optical microchip sensing platform demonstrating real-time, label-free detection of a wide range of biological agents is presented. SpectroSens™ chips containing high-precision planar Bragg gratings are exploited as low-cost, robust refractive index sensors. Sensitivity to biological agents is conferred by functionalising the sensing surface with antibodies selected against targets of interest. Several methods for immobilisation of bio-molecules on the metal oxide-coated sensing surface have been investigated. In this study, surfaces were modified with an amino-terminated silane monolayer and activated by glutaraldehyde cross-linking for covalent attachment of recombinant Protein A/G, to which agent-specific antibodies were immobilised. Binding of target antigens (introduced under flow) to the surface-immobilised antibodies results in localised changes in refractive index; upon laser-induced interrogation of the sensing region via optical fibres, these antibody-antigen interactions manifest as increases in wavelength of light reflected from the Bragg grating. Detection of biological targets including proteins (ovalbumin < 10 nm), viruses (MS2 < 100 nm), bacterial cells (Escherichia coli > 1 μm) and spores (Bacillus atrophaeus > 1 μm) in real-time has been demonstrated. The large size range of detection targets is attributed to a large penetration depth of the sensing light of >1 μm into the sample liquid using these sensors. This multi-analyte capability enables utilisation of this sensing technology in applications ranging from bio-threat detection for defence and homeland security to point-of-care clinical diagnostics. © 2010 Elsevier B.V. All rights reserved.


Holmes C.,University of Southampton | Carpenter L.G.,University of Southampton | Rogers H.L.,University of Southampton | Sparrow I.J.G.,Stratophase Ltd. | And 2 more authors.
Optics Express | Year: 2011

A set of rapid prototyping techniques are combined to construct a laterally-tilted Bragg grating refractometer in a novel planar geometry. The tilted Bragg grating is fabricated in a silica-on-silicon planar substrate using a dual beam direct UV writing (DUW) technique. Lateral cladding mode confinement is subsequently achieved by physically micromachining two trenches either side of the direct UV written waveguide. The resulting device is demonstrated as an effective refractometer, displaying a comparable sensitivity to tilted Bragg gratings in a fiber optical geometry, but with the added advantages of planar integration. © 2011 Optical Society of America.


Holmes C.,University of Southampton | Daly K.R.,University of Southampton | Sparrow I.J.G.,Stratophase Ltd. | Gates J.C.,University of Southampton | And 2 more authors.
IEEE Photonics Journal | Year: 2011

We present a planar-integrated optical surface plasmon refractometer. The fabricated device operates by grating-matched coupling between a core waveguide mode and a set of hybrid plasmon-dielectric modes of a much wider integrated structure. The constructed device incorporates a 50-nm-thin gold layer that separates a tilted planar-waveguide Bragg grating and a liquid analyte. It is demonstrated that polarization-dependent plasmon anomalies occur in the transmission spectra of the device, which are understood using a numerical Cauchy integral mode solving approach. Sensitivities in this planar-integrated device are comparable with existing fiber-based plasmonic sensors but with the advantages of planar integration and microfluidic adaptation. © 2009 IEEE.


Watts S.,Stratophase Ltd.
American Laboratory | Year: 2010

SpectroSens technology from Stratophase Ltd. enables measurements to be made in places where it is not possible to take laboratory equipment. The optical nature of the network of sensors means that all electrical components are housed in the control and readout unit, which can be situated far away from the point of measurement. With its fiber optic technology, SpectroSens can measure and analyze multiple parameters at numerous locations, simultaneously. Its ability to sense a multitude of parameters across the entire production process means that reactions and concentration levels can be monitored throughout. The small size of optical microchips and their natural versatility make them well suited to implementation in a vast array of sensing heads, offering a wide variety of system configurations. The SpectroSens technology is well within the guidelines of the FDA's process analytical technology (PAT) initiative. The SpectroSens technology can also be used by first responders and clinical point-of-care as a one-off, disposable sensor chip.


Belle S.,University of Applied Sciences Aschaffenburg | Scheurich S.,University of Applied Sciences Aschaffenburg | Hellmann R.,University of Applied Sciences Aschaffenburg | So S.,Stratophase Ltd. | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

We report on a refractive index sensor based on a planar Bragg grating (PBG) capable to online monitor the water content in Biodiesel and the amount of ethanol admixture to conventional fuels, respectively. Our results demonstrate the capability of the sensor to distinguish the transition between about 190 and 500 ppm water in Biodiesel, enabling to monitor the production process of Biodiesel in the relevant range according to industrial standards. The ethanol content in petrol has been investigated in the range of 0-100%, covering the entire standardized range of E-5 to E-85 fuel mixing ratios. These experiments reveal a sensitivity of 112 nm/riu allowing the measurement of the ethanol content with a resolution of 8.9·10-6. © 2010 Copyright SPIE - The International Society for Optical Engineering.


PubMed | Stratophase Ltd.
Type: Journal Article | Journal: Biosensors & bioelectronics | Year: 2011

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.

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