Size-Dependent and Antifouling Properties of Laser-Induced Graphene Electrodes toward Electrochemical Sensors - Food and Clinical Applications

Laser-induced graphene (LIG) has emerged as a promising electrode material in various applications, including analytical chemistry, due to its superior electrochemical properties and straightforward fabrication process. Its potential for use in electrochemical sensors necessitates a systematic investigation of its electrochemical properties to aid in sensor design and ensure fabrication consistency. In this study, we present the size-dependent electrochemistry and antifouling properties of LIG electrodes. Our findings indicate that smaller LIG electrodes exhibit faster electron transfer kinetics and greater reversibility, with a higher electroactive surface area compared to larger electrodes. Surface characterization revealed that the enhanced performance of smaller LIG electrodes is attributed to their higher surface roughness, increased defect density, and greater presence of oxygen-containing functional groups, which facilitate surface-confined electron transfer. Additionally, LIG electrodes demonstrate superior antifouling properties compared to screen-printed graphene electrodes, resisting both biofouling by bovine serum albumin and electrochemical fouling by various electroactive species. This improvement is likely due to differences in composition and surface hydrophobicity between the two electrode types. Finally, we showcase the application of LIG electrodes for the detection of carbofuran pesticide in food and hepatitis B antigen in clinical samples. The enhanced electrochemical properties of LIG significantly improve the analytical performance in these contexts. These findings underscore the potential of LIG electrodes in developing high-performance, reliable electrochemical sensors. In conclusion, LIG electrodes offer promising advantages for electrochemical sensor applications due to their enhanced electrochemical properties and superior antifouling capabilities, paving the way for advancements in analytical chemistry and biosensing.