The Effect of GO Flake Size on Field-Effect Transistor (FET)-Based Biosensor Performance for Detection of Ions and PACAP 38

The performance development of rGO-FET biosensors by analyzing the influence of GO flake size on biosensing efficacy. GO flakes of varying sizes, from 1 µm to 20 µm, were prepared under controlled conditions, followed by characterization through SEM and XPS to evaluate their size, surface area, and C/O ratio. The biosensing performance was systematically assessed by rGO-FET biosensors, examining the effects of GO flake size, C/O ratio, and film thickness. PACAP38 was employed as a biomarker for receptor-mediated detection, while chlorine ions served as model analytes for receptor-free small molecule detection. The results indicate that decreasing the GO flake size enhanced the performance for both target biomolecules. These findings highlight the crucial importance of selecting GO flake sizes specific to target analytes and detection strategies, thereby optimizing biosensor efficiency.