Research Symposium

BIO

I am a second-year undergraduate student studying biological sciences. I do undergraduate research at the Lazenby lab which is an analytical chemistry lab where I primarily work with microelectrodes. In the future, I hope to go to medical school.

Controlling surface morphology of electrodeposited gold for the preparation of electrochemical aptasensors

Abstract

Electrochemical, aptamer-based (EAB) sensors are an emerging class of biosensor with promising applications for point-of-care (POC) devices, and have been used to detect and quantify a wide range of biological and chemical analytes with high specificity. EAB sensors are typically fabricated on gold electrode surfaces, for which there are various methods of increasing the microscopic surface area. This is typically done to accommodate a greater number of aptamer probes on the surface to enhance the current response, which is particularly important for miniaturized sensors. Previous attempts to increase the surface area have not thoroughly assessed the effects of gold morphology on the performance of EAB sensors on both macroscale and miniaturized sensors. Small-scale sensors will enable spatiotemporally resolved measurements, however, there is a lack of aptamer-based probes fabricated on the micro and nanoscale, with few examples in literature. Here, we used electrodeposition to increase the microscopic surface area and to control surface morphology, to explore the resulting effects on EAB sensor performance on the macroscale and the microscale. Using aptamers specific to target analytes adenosine triphosphate (ATP) and dopamine (DA), square wave voltammetry, and cyclic voltammetry were used to interrogate the EAB sensors. Since electrodeposition on the two size scales resulted in different surface features, the comparison of macroscale and microscale sensors gave additional insights into how gold nanostructures affected the EAB sensor self-assembled monolayer and the overall sensor performance.

Keywords: Biosensing, Morphology, Aptasensor, Microelectrode, Nanostructure