2022 Annual Meeting

Cyclodextrin Electrochemical Biosensors for Arginine Detection

L-arginine is a significant amino acid that has many clinical and industrial applications. Arginine is involved in a number of metabolic pathways, playing a role in hormone secretion and regulation of the immune system. Arginine is considered an essential molecule for auxotrophic tumor growth, and acts as a biomarker for these tumors and many other physiological conditions. The continuous detection of arginine in clinical settings would allow for diagnosis of a variety of conditions. Proper arginine detection is also an important aspect of quality control for food and drink, in the prevention of health hazards for consumers. Biosensors could be capable of specific and swift detection of arginine levels in a sample; however, problems in reusability, stability, and selectivity prevent optimal detection of arginine.

We used different sized cyclodextrin to develop reusable cyclodextrin mediated surfaces for optimization of arginine detection. Cyclodextrins have a hydrophilic exterior and a hydrophobic inner cavity that is able to interact with arginine through hydrogen bonding. To build the surface, diazonium salt was grafted onto a glassy carbon electrode. Conjugation of the carboxylic groups was achieved using EDC/NHS chemistry, and then further modified with polypropylene glycol (PPG) or polyethylene glycol (PEG). Cyclodextrin was loaded onto the surface, and the surface was characterized with electrochemical impedance spectroscopy (EIS). The optimal frequency for our different surfaces were found in order to determine the most successful arginine detection.

Support was provided by a National Science Foundation EPSCoR award (#2119237).