Thyroxine biosensors: a review on progress and challenges

Hypothyroidism is a global concern that needs to be monitored, controlled and treated. Thyroxine is the most common biomarker for the diagnosis of hypothyroidism and a therapeutic hormonal replacement for hypothyroid patients. People suffering from hypothyroidism need to monitor their levels of thyroxine to avoid health complications. Diagnostic labs are not always easily accessible and, hence, point-of-care biosensors can become a useful alternative. Several studies have shown high sensitivity, selectivity and stability but there is no commercial point-of-care biosensing device available. This paper presents the critical aspects, including the need for thyroxine biosensors, the physicochemical properties of the thyroxine molecule, nanomaterials and bioreceptors used for sensing. The challenges and prospects of thyroxine biosensors are also discussed.