LAUSR

Graphene exhibits excellent physical, electronic and chemical properties that are highly desirable for biosensing application. However, most graphene biosensors are based on graphene lying flat on a substrate and therefore not utilizing its maximum specific surface area for ultra-sensitive detection. Herein, we showcased the novel use of photonic annealing on flexographic printed graphene-ethyl cellulose composite to produce vertically aligned graphene (VAG) biosensors for ultra-sensitive detection of algal toxin in drinking water. These VAG structures, which maximized the specific surface area of graphene, were formed by partial removal of the polymeric binder upon applying the intense pulsed light on the printed graphene. A label-free and low-cost VAG biosensor based on non-faradaic electrochemical impedance spectroscopy technique was fabricated. The biosensor exhibited a limit of detection (LoD) of 1.2 ng/L for MC-LR in local tap water. Such ultra-sensitive VAG biosensor is suitable for low-cost mass production using an integrated roll-to-roll flexographic printing with rapid photonic annealing technique.