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Next‐generation genome sequencing machines and Point‐of‐Care (PoC) in vitro diagnostics devices are precursors of an emerging class of Cyber‐Physical Systems (CPS), one that harnesses biomolecular‐scale mechanisms to enable novel "wet‐technology" applications in medicine, biotechnology, and environmental science. Although many such applications exist, testifying the importance of innovative life‐sciences instrumentation, recent events have highlighted the difficulties that designing organizations face in their attempt to guarantee safety, reliability, and performance of this special class of CPS. New regulations and increasing competition pressure innovators to rethink their design and engineering practices, and to better address the above challenges. The pace of innovation will be determined by how organizations manage to ensure the satisfaction of aforementioned constraints while also streamlining product development, maintaining high cost‐efficiency and shortening time‐to‐market. Model‐Based Systems Engineering provides a valuable framework for addressing these challenges. In this paper, we demonstrate that existing and readily available model‐based development frameworks can be adopted early in the life‐sciences instrumentation design process. Such frameworks are specifically helpful in describing and characterizing CPS including elements of a biological nature both at the architectural and performance level. We present the SysML model of a smartphone‐based PoC diagnostics system designed for detecting a particular molecular marker. By modeling components and behaviors spanning across the biological, physical‐nonbiological, and computational domains, we were able to characterize the important systemic relations involved in the specification of our system's Limit of Detection. Our results illustrate the suitability of such an approach and call for further work toward formalisms enabling the formal verification of systems including biomolecular components.

This work presents a versatile, membrane based electrochemical sensor with thin film electrodes fabricated through E-beam evaporation directly on porous materials (membranes). Here, the fabrication of the electrodes is described along with possible methods for integration in fluidic systems and characterisation of the electrodes through cyclic voltammetry (CV). The continued porous nature of the membranes after metal deposition is documented and its robustness and stability is investigated. Furthermore, amperometric sensing of dopamine is demonstrated as a proof of concept to validate the usability of the membrane sensor.

Protein nanofibrils and nanotubes are now widely accepted as having potential for use in the field of bionanotechnology. For this to be a feasible alternative to existing technologies, there is a need for a commercially viable source. Previous work has identified amyloid fibrils formed from crude crystallin proteins as such a source, since these fibrils can be produced in large quantities at a low cost. Applications include use of fibrils as templates for the formation of nanowires or as biosensing scaffolds. There remains a number of practical considerations, such as stability and the ability to control their arrangement. In this study, crude crystallin amyloid fibrils are shown to be stable in a range of biological and clean room solvents, with the fibril presence confirmed by transmission electron microscopy and the thioflavin T fluorescent assay. The fibrils were also immobilised between microelectrodes using dielectrophoresis, which enabled the recording of I-V curves for small numbers of fibrils. This investigation showed the fibrils to have low conductivity, with current values in the range of 10(-10) A recorded. This low conductivity could be increased through modification, or alternately, the fibrils could be used unmodified for applications where they can act as templates or high surface area nanoscaffolds.

In this report electrostatic force microscopy (EFM) is used to study different peptide self-assembled structures such as tubes and particles. It is shown that not only geometrical information can be obtained using EFM, but also information about the composition of different structures. In particular we use EFM to investigate the structures of diphenylalanine peptide tubes, particles, and CSGAITIG peptide particles placed on pre-fabricated SiO2 surfaces with a backgate. We show that the cavity in the peptide tubes could be due to the presence of water residues. Additionally we show that self-assembled amyloid peptides form spherical solid structures containing the same self-assembled peptide in its interior. In both cases transmission electron microscopy is used to verify these structures. Further, the limitations of the EFM technique are discussed, especially when the observed structures become small compared with the radius of the AFM tip used. Finally, an agreement between the detected signal and the structure of the hollow peptide tubes is demonstrated. SCANNING 33: 201–207, 2011. © 2011 Wiley Periodicals, Inc.