Mohd Azraie Mohd AzmiFatihatul Zuriati MakmonNur Azura Mohd SaidHazana RazaliMohd Ifwat Mohd GhazaliShahino Mah AbdullahOwen J Guy2024-12-102024-12-1020242024-12-10Mohd Azraie Mohd Azmi, Fatihatul Zuriati Makmon, Nur Azura Mohd Said, Hazana Razali, Mohd Ifwat Mohd Ghazali, Shahino Mah Abdullah & Owen J Guy APTES Functionalization of cGNP Electrochemical Immunosensor for Detection of Immunoglobulin G. (2024). INTERNATIONAL JOURNAL of INTEGRATED ENGINEERING, 16(7), 124–134. https://doi.org/10.30880/ijie.2024.16.07.0122229-838X2622-1110.30880/ijie.2024.16.07.012INTERNATIONAL JOURNAL of INTEGRATED ENGINEERING, Volume 16 Issue 7 Page (124–134)This paper demonstrates the development of carbon-based graphene nanoplatelet (cGNP) electrochemical immunosensor for the detection of immunoglobulin G (IgG). Initially, surface characterization via SEM revealed a smooth surface on the cGNP indicating successful GNP coverage using the drop-casting method. Screening of electrolyte buffers revealed that ferrocyanide and ferricyanide provided a favorable response with a current density of 9.369 µA. Functionalization of cGNP, was achieved using a 2% APTES solution during a 1-hour incubation period. Electrochemical characterization through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated excellent electrochemical activity when 0.1% bovine serum albumin (BSA) was employed as a blocking agent against 1 mg/ml IgG. Chronoamperometry (CA) confirmed IgG immobilization at a potential of 0.1 V. Notably, the immobilization of IgG resulted in an increase in the charge transfer resistance (Rct) to 69.8 ± 2.3 Ω, attributed to the hindrance of biological molecules on interfacial electron transfer. Consequently, the proposed cGNP electrochemical immunosensor platform exhibited a robust analytical response, characterized by optimal antibody binding capacity. This superior performance can be attributed to the presence of GNP on the screen-printed carbon electrode (SPCE), which enhanced surface area, conductivity, and overall electrical properties. These attributes make this platform a promising candidate for further research in protein biomarker diagnosis and related applications.en-USGraphene nanoplateletelectrochemical immunosensorAPTESimmunoglobulin Gbiosensotext::journal::journal article::research article124134167