Aptamer-Based Electrochemical Biosensing Platform for Detection of Hormonal Pollutants in Water
Poster Feb 25, 2015
Contreras Jimenez, G.; Eissa, S.; Ng, A.; Zourob, M.; Siaj, M.
Endocrine disrupters (EDs) are compounds that specifically interfere with the normal functions of the body’s endocrine system (system of glands for hormonal secretion) by causing adverse effects in both human and wildlife. Therefore, the routine, sensitive, reliable and cost effective detection methods for EDs are highly demanded.
In this work we present the selection and characterization of ssDNA aptamers that exhibit high affinity, specificity and sensitivity to progesterone (P4), 17b-estradiol (E2) and, norethisterone (NET). The aptamer selection was conducted by in vitro selections by incubating a huge ssDNA library of about 1.80x〖10〗^15 random sequences with the target analyte which has been previously immobilized on agarose beads. After certain cycles of selections, the enriched aptamers pool was cloned and sequenced. The dissociation constants (KD) of the selected aptamers were determined by fluorometry and by electrochemical impedance spectroscopy (EIS) methods. The KD values are in the low nanomolar range. Cross-reactivity tests for each aptamer demonstrated the high specificity to their target analyte. Additionally, circular dichroism (CD) spectroscopy measurements of the selected aptamers showed a remarkable conformational change upon binding the target analyte. The change in the conformation was exploited to design a biosensing platform to get a measurable signal after binding the specific analyte by following the redox process of a couple composed for [Fe(CN)6]3-/4-. For first time, an impedimetric aptasensor to detect progesterone was developed by yielding a limit of detection of 0.90ng/mL; for other analytes, the data will be presented and discussed in the programmed session of the conference.
We believe that the continuous selection of high affinity aptamers for other EDs and their integration in a biosensing platform will facilitate the routine monitoring of EDs in environment as well as clinical and medical diagnosis purposes.
Identifying Asthma-related Health Disparities Among Children in Hillsborough CountyPoster
Our project was to identify a geographic area demonstrating need for asthma interventions. By identifying different factors such as air quality, prevalence, asthma related hospitalizations and emergency department visits, we created a tool to identify and prioritize areas that could benefit from interventions like patient education and certification as an Asthma-Friendly School.
From Farm to Landfill: Results of a Campus-Community Awareness Event to Promote Sustainable Food SystemsPoster
In April 2017, a campus-community event (N=42 participants) was held to promote sustainable food systems by educating participants about concepts ranging from food production to nutrition and food waste management. This poster discusses the resulting increased awareness and knowledge of a our local food system among participants, which can be fostered through educational events that combine opportunities for research, teaching, and practice.READ MORE
Environmental Exposures and Inflammatory Bowel Disease in ChildhoodPoster
Inflammatory bowel diseases (IBD) often present in adolescence and affect >1.4 million persons in the US. Environmental exposures, notably air pollution and weather, have been suggested to contribute to IBD disease activity. Our goal was to evaluate relationships between environmental exposures and the prevalence and disease activity of pediatric IBD using novel data sources that take into account geographic location.READ MORE
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9th International Conference on Mass Spectrometry and Chromatography
Sep 21 - Sep 22, 2018