Liju Yang, Ph.D.
Assistant Professor of Pharmaceutical Sciences
Dieletrophoresis Enhanced Microchips for
Bacterial Pathogen Detection
Foodborne disease has been a serious threat to public health for decades and remains a major concern of our society. Foodborne pathogenic bacteria are the major cause of foodborne disease, accounting for 91% of the total outbreaks in the US. Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes are three major foodborne pathogens that are associated with many food products and causes numerous foodborne disease outbreaks. The development of effective detection methods is critical to implementation of effective responses to foodborne disease and to ensure food safety and security. Simultaneous detection of multiple species would reduce the number of assays to be performed in order to detect the possible presence of individual pathogens, thus saving considerable time and cost — yet it has not been well addressed and is still a technical challenge. Our goal with this research is to develop chip-based analytical devices for multiplex pathogen detection for laboratory, industry, and field uses. This technology has long-term potential applications not only in food inspections but also in clinical diagnostics and bio-security areas.
Nanomaterials Interfacing Biological Cells
The rising threat of foodborne pathogens demands effective methods of elimination. Although thermal heating, pasteurization, chemical sanitization (chlorine, chlorine dioxide), and physical disinfection methods (UV, electrolysis) are commonly used for pathogen reduction/elimination in food preservation processes, they suffer from high energy costs, low efficacy of antimicrobial activity, and/or short shelf life. This research revolves around developing a highly efficient antimicrobial method to reduce/eliminate pathogenic bacteria using carbon nanotubes (CNTs) and their unique thermal property induced by near Infrared (NIR) radiation.
Biosensors and Biochips for Early Cancer Diagnosis
Early diagnosis of cancer is crucial to successful treatment of the disease and increasing the patient’s survival rate. Currently, existing cancer diagnostic methods, which rely on a combination of radiological, surgical biopsy, and pathological assessment of tissue samples are generally not sensitive enough to diagnose cancer at an early stage because of the lack of reliable tumor markers and morphological features of early stage cancer cells. However, gene and protein expression profiles are known to be altered in early stage cancer. This research will focus on the differentiation of the electrical properties between cancer cells and normal cells for possible early diagnosis purposes. The objective is to design and develop a microchip based system that is capable of capturing single cancer cells into individual micro-scaled chambers to perform electrical impedance spectroscopy (EIS) at the single cell level. The success of this project will have impact in the areas of early, rapid and ultra-sensitive detection of oral cancer.