Carbon nanotubes-ionic liquid nanocomposites sensing platform for NADH oxidation and oxygen, glucose detection in blood

An excellent electrochemical sensing platform has been designed by combining the huge specific surface area of carbon nanotubes (CNTs) and the remarkable conductivity of ionic liquid (IL). IL can easily untangle CNTs bundles and disperse CNTs by itself under grinding condition due to the π–π interaction between CNTs and IL. The resulting nanocomposites showed an augmentation on the voltammetric and amperometric behaviors of electrocatalytic activity toward O2 and NADH. Therefore, such an efficient platform was developed to fabricate mediator-free oxygen sensor and glucose biosensor based on glucose dehydrogenase (GDH). O2 could be determined in the range of zero to one hundred percent of O2 content with the detection limit of 126 μg L−1 (S/N = 3). The glucose biosensor which was constructed by entrapping GDH into chitosan on the nanocomposites modified glassy carbon electrode surface, exhibited good electrocatalytic oxidation toward glucose with a detection limit of 9 μM in the linear range of 0.02–1 mM. We also applied the as-prepared sensors to detect oxygen and glucose in real blood samples and acquired satisfied results.

► An excellent sensing platform based on CNTs and IL has been designed.
► The CNTs-IL nanocomposites enhanced electrocatalytic activity of O2 and NADH.
► Mediator-free O2 sensor and glucose biosensor was developed.
► The as-prepared sensors were applied in real blood samples.