Analyte capture in microfluidic heterogeneous immunoassays
Despite the prevalence of microfluidic-based heterogeneous immunoassays, there is incomplete understanding of analyte capture parameters. This study presents computational results and corresponding experimental binding assays of analyte capture. Our results identify: 1) a “reagent-limited” regime, under constraints of finite sample volume and assay time; 2) a critical flow rate; 3) an increase in signal by using a short concentrated plug rather than a long dilute plug; 4) a requirement to eventually reach a reaction-limited operating regime to maximize the capture of analytes [1].
An inexpensive circuit designed for polarographic measurement of dissolved H2 over a wide concentration range is described. Examples of its application to measurements of hydrogenase and nitrogenase activities are presented.