Professor Robert A. Lazenby of Florida State University will give a seminar titled "Development of electrochemical aptasensors on the microscale, in arrays and at faster timescales" on Zoom from 3:30-4:30 p.m., Friday, April 15. Everyone is welcome to attend the seminar individually via Zoom or to come to CHEM 144, where the seminar can be viewed with other attendees. The talk is free and open to the public.

Lazenby is an assistant professor in the Department of Chemistry and Biochemistry at Florida State University. He joined the department in August 2019. Prior to this, he was a postdoctoral fellow at the University of Maryland, Baltimore County (2016-17) and the University of Cincinnati (2017-2019), working in the group of Ryan White at both institutions. Rob received his Ph.D. in chemistry at the University of Warwick in the United Kingdom, co-supervised by professors Patrick Unwin and Julie Macpherson (2010-2015). His Ph.D. was focused on electrochemical imaging using scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM), while his postdoctoral training was in the field of electrochemical biosensing.

Lazenby runs an electroanalytical chemistry lab that works on the development of electrochemical biosensors and probes including multi-analyte biosensors. His group's research aims to improve the performance of aptasensors using electrodeposition and to investigate electrocatalytic materials for water splitting reactions, principally the oxygen evolution reaction.

Structure-switching electrochemical aptasensors use a redox reporter-labelled aptamer in a self-assembled monolayer formed on a gold electrode to detect specific target molecules. This class of sensor has been used to detect various drugs, metabolites, toxins and biomarkers. In this work, an array of microelectrodes was used to support a series of different aptasensors. This enabled the simultaneous detection of adenosine triphosphate, dopamine and serotonin in solution, which could be extended to other analytes. The individually addressable microelectrodes were selectively modified using controlled adsorption and desorption of the different aptamers. The use of multiple aptasensors with cross-selectivity, in an array, allowed improved specificity while the sizescale and geometry of the array will allow localized measurements to be performed.

Increasing the microscopic surface area of the electrodes was achieved using electrodeposition of gold, and this was required to accommodate a greater number of adsorbed aptamers to maximize the sensor signal. The gold morphology of deposited electrodes was shown to affect the formation of the sensor monolayer, which manifested in changes to the probe number density, magnitude of signal change in response to analyte and apparent binding affinity. Given the potential application to the detection of biologically relevant analytes, a fast experimental timescale of the method is required. An amperometric method was also developed to enable two millisecond time resolution, rather than the conventional voltametric methods that typically require tens of seconds per measurement.

To attend the seminar, please visit the Zoom link.

• Meeting ID: 837 3375 9275
• Passcode: Two+Two=5