Researchers from Tufts University recently developed a graphene-enhanced highly sensitive saliva-based cortisol sensor – eliminating the need for invasive blood tests.
The Point-of-Care (POC) electrochemical biosensor boasts a detection limit of 0.24 fg/mL, making it 100 times more sensitive than existing saliva tests. This innovation relies on the Gii-Sens “electrode” – a sensing strip produced by nanomaterial company, iGii – integrated into the sensor.
The novel non-invasive diagnostic tool provides reliable salivary cortisol profiles and could help identify early onset of stress related disorders, measure the wellbeing of frontline workers and optimize athlete performance. Profiling cortisol in saliva could improve understanding of conditions that affect and are affected by long-term stress levels. Cortisol, a hormone associated with stress, fluctuates throughout the day and varies significantly among individuals. It is often tested through either saliva or blood tests.
Traditional technologies have struggled to provide reliable and sensitive detection from saliva due to it having low concentrations of cortisol. Blood tests, while more accurate, are invasive, especially if they have to be taken multiple times a day.
The Gii-Sens electrode, created by iGii (formerly Integrated Graphene), is a unique, porous, 3D carbon nanostructure that has a high surface area and highly conductive carbon-based electrode platform. It is more sensitive, and more sustainable, compared to other commonly used sensor materials, such as gold. The fabrication process of this ultra-sensitive biosensor involves attaching anti-cortisol monoclonal antibodies (mAb-cort) to the PBASE-NHS/GF electrode through non-covalent immobilization. This method preserves bioreceptor Graphene's structural integrity and electrical conductivity while facilitating efficient and controlled antibody immobilization, thereby enhancing the biosensors’ sensitivity.
Jean-Christophe Granier, Chief Executive Officer, iGii, said: “These results are another clear example of Gii-Sens being integrated into different biosensors to test different conditions. As well as being considerably more accurate and reliable than existing tests, Gii-Sens is much more cost-effective and sustainable than other materials, such as gold, used in medical diagnostic tests”.
Gii-Sens electrodes are said to outperform screen-printed options on multiple levels and create a better, faster experience. The technology can be used to measure a wide range of health and environmental markers in saliva and other fluids. iGii is working closely with medical technology companies worldwide to enhance their existing diagnostic tests or help design new ones that cover all aspects of Assay Development, from initial design concept to full integration and FDA approval.
