Transdermal Optical Microneedle Sensors for Continuous Monitoring of Physiological Analytes in Interstitial Fluid
Abstract
Luminescence-based microneedle sensors offer great potential for minimally invasive, real-time physiological monitoring but are largely unexplored compared to electrochemical approaches. The objective of this effort is to fabricate and validate microneedle sensor patches that contain luminescent analyte-sensing dyes for phosphorescence lifetime-based detection of tissue oxygenation and ratiometric intensity-based detection of electrolytes. Along with wearable, wireless readers (BaySpec), microneedles could allow for minimally invasive detection of such conditions as hypoxia, hyperoxia, and hydration state. For risk reduction, two microneedle platforms are being assessed: 1) Synthetic polymer microneedles coated with a dye-containing hydrogel (BlueHalo) and 2) Dye-loaded silk nanoparticles localized in the tips of naturally derived, bioresorbable silk-based microneedles (Tufts University). Multiple oxygen-sensing microneedle patches were validated in vitro and shown to exhibit ideal sensitivities for the physiological regime, and an accompanying wireless, lifetime-based reader and smartphone app were developed. Custom dyes were synthesized (AFRL) to enable electrolyte sensing, and a ratiometric sodium-sensing microneedle sensor patch was demonstrated in vitro, exhibiting suitable sensitivity and rapid response times. Efforts to fabricate an intensity-based reader, validate sensor performance in vivo, and extend the platform to additional electrolytes are ongoing.
Biography
Dr. Lucas K. Beagle graduated from the Wright State University in 2005 with a B.S. in biological sciences, Youngstown State in 2008 with a master’s in chemistry and University of Dayton in 2020 with a master's in bioengineering. He completed his Ph.D. in Chemistry from the University of Florida in 2012 with a focus on heterocycles and medicinal chemistry. He is currently Senior Director of Biological, Electrical and Nanoscale Technologies Division at BluHalo, supporting research in the Materials and Manufacturing Directorate at the Air Force Research Laboratory. His research areas include synthesis and processing of covalent organic frameworks (COFs) and other polymers, microwave chemistry and processing, hybrid organic/2D-inorganic systems, 2D heterostructures, and novel design of chemical and biological sensors.