The aging of the population amplifies the need for both early detection and continuous monitoring of biomarkers of disease. Biosensing is the determination of the amount of a biomarker using a measurable signal. Over the last decade, there has been extensive studies on the development of biosensors that allow real time monitoring, miniaturized implantable devices or handheld testing kits. Lignin has shown increasing potential as the precursor for biosensor materials. This chapter focuses on this new and exciting field where the development of lignin for biosensing applications offers a sustainable biomedical advance. While this field is still in its infancy, the influence of lignin chemical structure on the performance of the sensors shows promising results and places this natural polymer at the forefront of the next generation of biosensors.