Biomedical subjects

Michaela Bowden

Publications and source records attributed to Michaela Bowden.

4 recordsLinked to original sources

PubMed2005

Development of a microfluidic platform with an optical imaging microarray capable of attomolar target DNA detection.

In this paper, DNA hybridization in a microfluidic manifold is performed using fluorescence detection on a fiber-optic microarray. The microfluidic device integrates optics, sample transport, and fluidic interconnects on a single platform. A high-density optical imaging fiber array containing oligonucleotide-labeled microspheres was developed. DNA hybridization was observed at concentrations as low as 10 aM with response times of less than 15 min at a flow rate of 1 microL/min using 50 microL of target DNA samples. The fast response times coupled with the low sample volumes and the use of a high-density, fiber-optic microarray format make this method highly advantageous. This paper describes the initial development, optimization, and integration of the microfluidic platform with imaging fiber arrays.

Bacillus thuringiensis↗

PubMed2003

CO2 laser microfabrication of an integrated polymer microfluidic manifold for the determination of phosphorus.

A simple colorimetric technique is implemented in a polymer microfluidic manifold. The simple chemistry aids an uncomplicated microchannel design, which is fabricated by CO(2) laser ablation. Issues such as bonding of multiple layers, alignment of micro-fabricated structures and integration of optical components are addressed. A demonstration of a stopped flow regime in the microfluidic manifold is also presented.

Journal Article↗

PubMed2002

A prototype industrial sensing system for phosphorus based on micro system technology.

Progress in the development of a miniaturised microfluidic instrument for monitoring phosphorus in natural waters and wastewater is presented. The yellow colorimetric method for phosphate analysis has been transferred to a microfluidic chip configuration This simple method employs one reagent mixed in a 1:1 ratio with a sample to produce a yellow colour absorbing strongly below 400 nm. A stopped flow approach is used which, together with the very rapid kinetics and simple reagent stream, enables a very uncomplicated microfluidic manifold design to be adopted. The working wavelength is 380 nm to coincide with the peak output of a recently developed UV-LED narrow bandwidth light source. The limit of detection for the yellow method is 0.2 ppm with a dynamic linear range from 0-50 ppm possible. The reaction time at room temperature is less than 3 min, which means that up to 20 samples per hour can be analysed.

Journal Article↗

PubMed2002

Analysis of river water samples utilising a prototype industrial sensing system for phosphorus based on micro-system technology.

The application of a phosphorus monitoring device based on microsystems technology (MST) to the analysis of river water is presented. An alternative to the standard molybdenum blue method known as the yellow vanadomolybdophosphoric acid method has been very effectively implemented. The method is simple, a reagent and sample are mixed in a 1:1 ratio forming a yellow complex that absorbs strongly below 400 nm in the UV spectrum. The kinetics of the reaction are rapid and sample turnaround is typically 3 min at room temperature. Therefore a very uncomplicated microfluidic design can be adopted. The working wavelength was chosen as 380 nm to coincide with the peak output of a UV-LED narrow bandwidth light source recently developed by Nichia. The limit of detection for the yellow method in the microfluidic system is 0.2 ppm with a dynamic linear range from 0-50 ppm. The method was applied to a measurement of phosphorus in a local river at specific sampling points along its course.

Absorption↗