2012-341 Quantum Dot Enabled Detection of Escherichia Coli using a Cell-Phone

Summary:
UCLA researchers in the Department of Electrical Engineering have developed a platform that can detect E. coli using a cell phone.

Background:
Water and food-associated diseases still pose considerable public health threat even in highly industrialized parts of the world, causing significant amount of hospitalizations and deaths every year. For example, Escherichia coli (E. coli) can easily contaminate food or drinking water, posing a significant threat to public health safety. In order to prevent such serious health problems, and economic loss due to outbreaks caused by water-/food-borne diseases, a gold standard detection method (EPA Method 1604) has been developed. However, this method requires membrane filtration, colony culture, and a fluorescent microscope.

Innovation:
Researchers at UCLA have developed a compact, lightweight, and cost-effective fluorescent imaging and sensing platform for detecting E. coli using a cell phone. This platform combines antibody functionalized glass capillaries with quantum dots as signal reporters to specifically detect E. coli particles in liquid samples using a lightweight (28 g) and compact (3.5 cm x 5.5 cm x 2.4 cm) attachment. This attachment acts as a fluorescent microscope that quantifies the emitted light from each capillary after capture of E. coli particles within the sample of interest.

 Potential Applications:

• E. coli detection in water and food

Advantages:

• Compact, lightweight compared to full fluorescent microscopy set-up
• Portable
• Sensitive (detection limit of 5-10 cfu/mL)

Related Materials:

• Zhu, Hongying, Sam Mavandadi, Ahmet F. Coskun, Oguzhan Yaglidere, and Aydogan Ozcan. "Optofluidic fluorescent imaging cytometry on a cell phone." Analytical chemistry 83, no. 17 (2011): 6641-6647.
• Zhu, Hongying, Oguzhan Yaglidere, Ting-Wei Su, Derek Tseng, and Aydogan Ozcan. "Cost-effective and compact wide-field fluorescent imaging on a cell-phone." Lab on a Chip 11, no. 2 (2011): 315-322.
• Zhu, Hongying, Uzair Sikora, and Aydogan Ozcan. "Quantum dot enabled detection of Escherichia coli using a cell-phone." Analyst 137, no. 11 (2012): 2541-2544.
• Bishara, Waheb, Hongying Zhu, and Aydogan Ozcan. "Holographic opto-fluidic microscopy." Optics express 18, no. 26 (2010): 27499-27510.