BEGIN:VCALENDAR VERSION:2.0 PRODID:-//ZContent.net//ZapCalLib 1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT SUMMARY:Using DNA-analyte conjugates for adaptable sensors and pneumatic co mputers for fluidic sampling LOCATION:Chemistry A101 TZID:America/Denver DTSTART:20221109T160000 UID:2026-04-16-23-12-04@natsci.colostate.edu DTSTAMP:20260416T231204 Description:About the Seminar\n\nSensors based on electrochemical (EC) read out offer low cost\, miniaturization\, and adaptability to the point-of-ca re (POC). Nonetheless\, most EC sensors are specialized to a particular ta rget\, and there remains a need for a robust EC biosensor platform for the multitude of biomarkers that are not EC-active\, do not undergo enzymatic conversion\, or are not suited for potentiometry [1\,2].  While aptamer- based EC sensors have been proven for sensing in living animals with tempo ral resolution of a few seconds [3]\, most method development has been tar get-focused\, lacking generalizability [4].  Presently\, the clinical EC toolbox is a conglomerate of targeted methods\, and there is a pressing ne ed to develop a single EC platform amenable to rapid\, generalizable\, qua ntitative readout of multiple classes of clinically relevant targets.\n\nA direct\, generalized EC sensing approach with minimal added reagents or a mplification steps is preferred [5\,6].  Our group has been working to ad dress this need and expand to more analyte classes for several years\, and in 2019 we designed a versatile DNA-nanostructure architecture attached t o gold electrode surfaces [6].  Initially\, our sensors were validated wi th biotechnology controls\, antibodies\, and with a small molecule immunom odulatory drug in human serum.  In this lecture\, I will discuss our effo rts to expand the generalizability of our sensor platform\, chiefly throug h custom synthesis of varied DNA-analyte bioconjugates to incorporate with in the DNA-nanostructure\, specifically DNA-peptide and DNA-small molecule conjugates.  Using the same DNA nano-architecture\, sensors have been va lidated in 98% human serum for a variety of targets\, several encompassing the human clinical range—a peptide drug (exendin-4) [7]\, a larger prot ein (creatine kinase)\, and smaller molecules or steroid hormones (testost erone\, estradiol\, progesterone\, cortisol).  Overall\, this new DNA nan ostructure platform provides a generalizable sensor with minimal workflow\ , direct-readout\, and the capability to expand EC sensing to a wide varie ty of clinically important analytes.\n\nLastly\, I will discuss several ad vancements we have made on automating microfluidic flow control\, leveragi ng digital circuit analogies to develop on-chip pneumatic circuits [8\,9].   Integrated\, pneumatic microfluidic valves have provided many powerful capabilities\, giving users exquisite fluid control at the nanoliter and p icoliter scales—including in EC sensors systems.  However\, control of these valves requires multiple\, computer switchable pressure or vacuum li nes\, limiting accessibility to those with expertise or expensive control systems.  I will discuss two advancements we have made with devices fabri cated by resin-based 3D printers: 1) 3D printing of pneumatic circuits and oscillators with inexpensive equipment\, and  2) the use of smartphone a udio and video analysis to study these circuits.  The automated oscillato rs are tunable from 0.5 to 100 Hz and can pump solution on microdevices wi th only a single vacuum input line.\n\nReferences:\n\n Turner\, A. P.\, C hemical Society Reviews 2013\, 42\, 3184-96.\n Wilson\, G. S.\; Johnson\, M. A.\, Reviews 2008\, 108\, 2462-81.\n Idili\, A.\; Gerson\, J.\; Kipp in\, T.\; Plaxco\, K. W.\, Chem. 2021\, 93\, 4023-32.\n Labib\, M.\; Sar gent\, E. H.\; Kelley\, S. O.\, Reviews 2016\, 116\, 9001-90.\n Das\, J. \; Gomis\, S.\; Chen\, J. B.\; Yousefi\, H.\; Ahmed\, S.\; Mahmud\, A.\; Z hou\, W.\; Sargent\, E. H.\; Kelley\, S. O.\, Nature Chem. 2021\, 13\, 428 -434.\n Somasundaram\, S.\; Easley\, C. J.\, Am. Chem. Soc. 2019\, 141\, 11721-11726.\n Khuda\, N\; Somasundaram\, S.\; Easley\, C. J.\, ACS Sens ors 2022\, 7\, 784-789.\n Grover\, W. H.\; Ivester\, R. H. C.\; Jensen\, E. C.\; Mathies\, R. A.\, Lab Chip 2006\, 6\, 623-631.\n Duncan\, P. N.\; Nguyen\, T. V.\; Hui\, E. E.\, Natl. Acad. Sci. USA 2013\, 110\, 18104-1 8109.\n\nAbout the Speaker\n\nChristopher J. Easley is currently the C. Ha rry Knowles Professor and Graduate Program Officer (GPO) of Chemistry and Biochemistry at Auburn University.  He received his B.S. degree in chemis try at Mississippi State University in 2002\, where he did undergraduate r esearch with Prof. Charles S. Henry (now at Colorado State U.).  He earne d his Ph.D. in bioanalytical chemistry from the University of Virginia in 2006\, with training from Prof. James P. Landers.  His postdoctoral train ing was provided by Prof. David W. Piston at the Vanderbilt University Med ical Center in the Department of Molecular Physiology and Biophysics\, fro m 2006-2008.  He began his independent career at Auburn in 2008 and was p romoted to full professor in 2018.  Prof. Easley is currently an Associat e Editor at Analytical Methods (2017-present\, Royal Society of Chemistry) and a board member of the Boshell Diabetes and Metabolic Diseases Researc h Program at Auburn University.  He is also a Scientific Advisor for Inna med\, Inc.\, a consultant with Scitemex\, and holds several U.S. patents b ased on biosensing and microfluidics.  Recently\, he was awarded the Mid- Career Achievement Award by the AES Electrophoresis Society (2019) and the COSAM Dean’s Research Award at Auburn (2020).  In work funded mostly b y the National Institutes of Health (NIH)\, his bioanalytical research lab oratory develops droplet-based microfluidic methods to study dynamic funct ion of small numbers of cells in intact\, primary tissue (ex vivo) from mo use models of disease.  To accommodate bioanalysis at the microscale\, th e team also develops DNA-driven assays for highly sensitive analyte quanti fication using both fluorescence and electrochemistry\, work funded by bot h the NIH and National Science Foundation (NSF).  Overall\, the Easley la boratory has focused their customized analytical tools on real-world appli cations in clinical biosensing as well as on fundamental understanding of dynamic function of adipose tissue\, which is of paramount importance in d iabetes\, obesity\, and metabolic syndrome.  Since 2008\, Prof. Easley ha s directly mentored 5 postdocs\, 24 graduate students\, and 34 undergradua te students through his research program. 4:00 pm END:VEVENT END:VCALENDAR