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The diagnosis of infectious diseases in the Developing World is technologically challenging requiring complex biological assays with a high analytical performance, at minimal cost. By using an opto-acoustic immunoassay technology, integrating components commonly used in mobile phone technologies, including surface acoustic wave (SAW) transducers to provide pressure driven flow and a CMOS camera to enable lensfree detection technique, we demonstrate the potential to produce such an assay. To achieve this, antibody functionalised microparticles were manipulated on a low-cost disposable cartridge using the surface acoustic waves and were then detected optically. Our results show that the biomarker, interferon-γ, used for the diagnosis of diseases such as latent tuberculosis, can be detected at pM concentrations, within a few minutes (giving high sensitivity at a minimal cost). [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an in situ impedance chip system, which allows studying the effects of drugs on the behaviors of living cell in real-time. A new label-free measurement approach is introduced, which enables to assess the extent of the adhesion of a cell population to the extracellular matrix (ECM)-coated microelectrode array, by adding together all the impedance changes from individually controlled microelectrodes. A high sensitivity was demonstrated and allowed us to monitor cell attachment with the resolution of a “few cells”. The dose and pre-incubation time effects of antibodies against β1-integrin and its subunit α2β1-integrin on the adhesion behavior of NCI-H460 lung cancer cells to collagen type I was extensively studied. Results show that both anti-β1-integrin and anti-α2β1-integrin inhibit NCI-H460 cells attachment to collagen I. This indicates that β1-integrin is present on the surface of NCI-H460 cancer cells, and that its subunit α2β1 significantly affects NCI-H460 cells attachment on collagen I. [Copyright &y& Elsevier]