Center for Embedded Network Sensing

With the confocal Laser induced fluorescent sensor developed in our lab concentrations as low as 5.9 fM can be detected. We will work with Professor Caron at USC and Professor Tai at Caltech to detect Amnestic shellfish poisoning (ASP) caused by ingestion of contaminated shellfish by Domoic Acid (DA) causes death both in human beings and animals when the contamination is higher than 20 ?g (64 ?Mole) of DA per gram of shellfish tissue. DA is produced by a number of algae, including microalgae of the genus Pseudo-nitzschia, and it is accumulated by shellfish filter feeding during Pseudo-nitzschia blooms. Competitive ELISA is used for DA detection down to 0.2 ng/mL. The detection limit not low enough, the confocal Laser induced fluorescent sensor is going to be used to detect lower concentrations of DA. In our sensor optics are used to define a very small detection volume. In this method, molecules of interest are labeled with fluorophores. A droplet of sample is added to the sensor. The target molecules which are conjugated with fluorescent molecules will move in and out of the detection volume by diffusion and Brownian motion. A photon burst is observed when the molecule passes the detection volume and the number of peaks per unit of time indicates the concentration of sample under study. Using the pinhole for confocal microscopy will reduce the background noise coming from the reflection and spurious fluorescence background and going to lower concentration down to single molecules will be made possible. The molecule under study can be easily changed with this sensor.