@article {228,
	title = {A rapid diffusion immunoassay in a T-sensor.},
	journal = {Nat Biotechnol},
	volume = {19},
	year = {2001},
	month = {2001 May},
	pages = {461-5},
	abstract = {<p>We have developed a rapid diffusion immunoassay that allows measurement of small molecules down to subnanomolar concentrations in <1 min. This competitive assay is based on measuring the distribution of a labeled probe molecule after it diffuses for a short time from one region into another region containing antigen-specific antibodies. The assay was demonstrated in the T-sensor, a simple microfluidic device that places two fluid streams in contact and allows interdiffusion of their components. The model analyte was phenytoin, a typical small drug molecule. Clinically relevant levels were measured in blood diluted from 10- to 400-fold in buffer containing the labeled antigen. Removal of cells from blood samples was not necessary. This assay compared favorably with fluorescence polarization immunoassay (FPIA) measurements. Numerical simulations agree well with experimental results and provide insight for predicting assay performance and limitations. The assay is homogeneous, requires <1 microl of reagents and sample, and is applicable to a wide range of analytes.</p>},
	keywords = {Antibody Specificity, Antigen-Antibody Complex, Binding, Competitive, Diffusion, Fluorescence Polarization Immunoassay, Immunoassay, Molecular Weight, Phenytoin, Rheology},
	issn = {1087-0156},
	doi = {10.1038/88135},
	author = {Hatch, A and Kamholz, A E and Hawkins, K R and Munson, M S and Schilling, E A and Weigl, B H and Yager, P}
}
@article {229,
	title = {Quantitative analysis of molecular interaction in a microfluidic channel: the T-sensor.},
	journal = {Anal Chem},
	volume = {71},
	year = {1999},
	month = {1999 Dec 1},
	pages = {5340-7},
	abstract = {<p>The T-sensor is a recently developed microfluidic chemical measurement device that exploits the low Reynolds number flow conditions in microfabricated channels. The interdiffusion and resulting chemical interaction of components from two or more input fluid streams can be monitored optically, allowing measurement of analyte concentrations on a continuous basis. In a simple form of T-sensor, the concentration of a target analyte is determined by measuring fluorescence intensity in a region where the analyte and a fluorescent indicator have interdiffused. An analytical model has been developed that predicts device behavior from the diffusion coefficients of the analyte, indicator, and analyte--indicator complex and from the kinetics of the complex formation. Diffusion coefficients depend on the local viscosity which, in turn, depends on local concentrations of all analytes. These relationships, as well as reaction equilibria, are often unknown. A rapid method for determining these unknown parameters by interpreting T-sensor experiments through the model is presented.</p>},
	keywords = {Kinetics, Models, Chemical, Spectrometry, Fluorescence},
	issn = {0003-2700},
	author = {Kamholz, A E and Weigl, B H and Finlayson, B A and Yager, P}
}
