Publications by authors named "Syed Barizuddin"

Background: Timely diagnosis of tuberculosis disease is critical for positive patient outcomes, yet potentially millions go undiagnosed or unreported each year. Sputum is widely used as the testing input, but limited by its complexity, heterogeneity, and sourcing problems. Finding methods to interrogate noninvasive, non-sputum clinical specimens is indispensable to improving access to tuberculosis diagnosis and care.

View Article and Find Full Text PDF

Developing rapid and sensitive methods for the detection of pathogenic Escherichia coli O157:H7 remains a major challenge in food safety. The present study attempts to develop an immunofluorescence technique that uses Protein-A-coated, magnetic beads as the platform. The immunofluorescence technique described here is a direct detection method in which E.

View Article and Find Full Text PDF

A method combining immunomagnetic separation and fluorescent sensing was developed to detect Escherichia coli (E. coli) O104:H4. The antibody specific to E.

View Article and Find Full Text PDF

A gold interdigitated microelectrode (IME) impedance biosensor was fabricated for the detection of viable Escherichia coli O157:H7. This sensor was fabricated using lithography techniques. The surface of the electrode was immobilized with anti-E.

View Article and Find Full Text PDF
Article Synopsis
  • Electrochemical microelectrodes are used to detect amperometric current spikes from individual vesicle exocytosis, and new transparent multielectrochemical electrode arrays on microchips are being developed to automate this measurement.
  • Efficient targeting of about 75% of individual cells to electrode sites is achieved through the use of microwell traps and specific surface treatments that encourage cell adhesion where needed while preventing it elsewhere.
  • The new device shows promise for high-throughput studies and could be useful in screening drugs or toxins that affect exocytosis, with tests on bovine adrenal chromaffin cells demonstrating consistent and reusable performance.
View Article and Find Full Text PDF

Here we describe a method to fabricate a multi-channel high-throughput microchip device for measurement of quantal transmitter release from individual cells. Instead of bringing carbon-fiber electrodes to cells, the device uses a surface chemistry approach to bring cells to an array of electrochemical microelectrodes. The microelectrodes are small and "cytophilic" in order to promote adhesion of a single cell whereas all other areas of the chip are covered with a thin "cytophobic" film to block cell attachement and facilitate movement of cells to electrodes.

View Article and Find Full Text PDF

Neurons and endocrine cells secrete neurotransmitter and hormones in discrete packets in a process called quantal exocytosis. Electrochemical microelectrodes can detect spikes in current resulting from the oxidation of individual quanta of transmitter only if the electrodes are small and directly adjacent to release sites on the cell. Here we report development of a microchip device that uses microfluidic traps to automatically target individual or small groups of cells to small electrochemical electrodes.

View Article and Find Full Text PDF

Electrochemical measurement of transmitter or hormone release from individual cells on microchips has applications both in basic science and drug screening. High-resolution measurement of quantal exocytosis requires the working electrode to be small (cell-sized) and located in immediate proximity to the cell. We examined the ability of candidate electrode materials to promote the attachment of two hormone-secreting cell types as a mechanism for targeting cells for to recording electrodes with high precision.

View Article and Find Full Text PDF