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Samantha Mensah

Undergraduate Major: Chemistry

Future Plans: Ph.D. in Chemistry

Samantha Mensah

Samantha Mensah is a native of New York and was raised in South Florida. Her academic interests include analytical chemistry, physical chemistry, and theoretical physics. Through community outreach, she is an active participant in encouraging K-12 students to pursue post-secondary education and careers in STEM. Samantha has been conducting research alongside Dr. Chumbimuni-Torres since January of 2013. Her research centers on the development and optimization of sensors that can be used to determine the presence of ions in the body and environment. She has published her research findings in a peer-reviewed journal and plans to earn her Ph.D. in Chemistry.

All-In-One Paper-Based Ion Sensors

Mentor: Dr. Karin Chumbimuni-Torres,  Department of Chemistry, University of Central Florida 

Abstract: Although ion-selective electrodes (ISEs) are pivotal for electrochemical quantifications, they require a cumbersome pretreating step in a solution of the ion ion of intereste prior to electroanalyses for a minimum of 10 hours. During that period, a zero-current ion flux is established while the ionophore binds to the ion of interest. This required step highly limits ISEs’ in-field application. Here, we present ISEs for Na+, Ag+, and I- with submicromolar limits of detection that do not require pre-conditioning. The ISE membranes contained ionophore, ion-exchange sites and a PVC/DOS matrix. Further, 5 mmol of the ion of interest was added directly to the Ag+-selective and Na+-selective membranes, and 0.75 mmol of the ion of interest was added to the I-- selective membrane. Potentiometric measurements were conducted without any pretreating using a high-input impedance data acquisition system. Results obtained indicate that introduction of analyte ion directly to the ion-selective membrane allows the ionophore to chelate with the analyte and execute the ion-exchange process solely within the membrane, eliminating the role of the membrane-sample boundary in the pretreating process. This opens the door to the development of a multiplex analysis sensor, wherein the entire potentiometric measurement setup may be joined into a single all-in-one device which works as both a reference and working electrode. This device is far more convenient than its glass-bodied counterpart for in-field and point-of-care medical/environmental diagnostics.