The current review article focuses on the significance of various biosensors for detecting IgG antibodies and their working principles, highlighting the importance of IgG as a biomarker tool for diagnostic applications in various pathological conditions. The review discusses the different types of biosensors, their classification based on transduction properties, and biorecognition elements. Specifically, the comparison is made between electrochemical biosensors, such as impedimetric, amperometric, potentiostatic and conductometric, which have evolved over the years with major developments in their initial use as glucose sensors for IgG detection in a variety of diseases. However, the current demand for IgG biosensors in disease prevention, such as diagnosis of prostate cancer, tumor markers, autoimmune diseases, and COVID-19, is significant. Despite the advantages, IgG biosensors have some limitations, such as detection limit, detection time, selectivity, and difficulty in maintaining a high throughput system. Advances in nanomaterial production, such as carbon nanotubes, nanoparticles, and metallic organic frameworks, have the potential to address some of these limitations. Moreover, the article highlights the balance between specificity and versatility as a major challenge in IgG biosensor development. While expensive biosensors that utilize single IgG molecules maintain specificity, making them affordable requires expanding IgG detection with protein molecules using adaptable machine learning models that are programmed iteratively. With more suitable nanomaterials and well-designed software, handheld devices could be developed for point-of-care detection of IgG, making it possible for people to perform diagnostic tests in their own homes. Therefore, future research should focus on improving the sensitivity, selectivity, and cost-effectiveness of IgG biosensors for widespread use in disease prevention and diagnosis.