Z.R. Baird
BioMEMS Diagnostics, Inc.,
United States
Keywords: biosensor, multiplexed diagnostics, monitoring
Summary:
BioMEMS Diagnostics Inc. has developed a novel biosensor for multiplexed, precision diagnostics at the point-of-need. The sensor utilizes existing manufacturing technologies to enable low-cost, large-scale production and is easily adaptable to commercially available antibody pairs in a substrate-free, electrochemically read immunoassay format. Internal testing of the sensor has demonstrated quantitative detection as low as 0.3 pM (20 pg/mL) for human serum albumin with good reproducibility. The range of the sensor and assay is adjustable with quantifiable detection shown up to 2500 pM (166 ng/mL) allowing for a wide range of analyte concentrations on a single sensor. In the case of intact pathogen analysis, the pathogens are captured by the sensor surface and can be further analyzed using traditional molecular analysis of the genetic material present. The sensitivity, combined with the ability for follow-up analysis has the potential to be a valuable tool in the diagnosis and treatment of hospital acquired infections where results may not be received for days due to sample culture and analysis. Briefly, the sensor is composed of 12 individual sensing elements, each of which are functionalized independently to perform separate assays from the same sample. The sensor chip utilizes flow-through vertical washing and recirculation to enable simplified on-sensor mixing while simultaneously increasing exposure of the sensing elements to the target analytes. This approach shortens the time-to-result to as little as 5 minutes and overcomes the diffusion-limited assay time of many sensors relying on microfluidics for fluidic handling. Unlike the majority of lab on a chip platforms, the BioMEMS sensor does not require redesign or modification when configuring for a new assay based on the simplified fluidics of the porous sensor. The sensor construction was optimized with a design-for-manufacture approach to decrease cost and enable the use of existing automation strategies. In some cases it is possible to functionalize as many as 50,000 sensors in a single batch. Unlike many lab-on-a-chip platforms, the BioMEMS sensor does not rely on relatively expensive silicon chip-based manufacturing but makes use of multilayered printed circuit boards to decrease cost while retaining sensitivity in a multiplexed assay format. By employing substrate-free electrochemical detection, a single buffered solution can be used for all aspects of the assay to simplify design of a “cartridge” which contains all elements necessary for sample collection, dilution, analysis, and waste containment. A conceptual prototype of such a cartridge has shown recirculation and containment of sample by actuation with a low-power, miniature vacuum pump as is already present on the BioMEMS Analyzer used to read assay results from the sensor. The BioMEMS Analyzer utilizes wireless communication to directly transfer raw data to a computer or smart phone for further analysis and display of results. These results can be directly sent to a physician to aid in rapid diagnosis and provide consumer accessible information for improved healthcare outcomes.