In situ growth of TiO2 nanowires on Ti3C2 MXenes nanosheets as highly sensitive luminol electrochemiluminescent nanoplatform for glucose detection in fruits, sweat and serum samples

A sensitive electrogenerated chemiluminescence (ECL) biosensor for glucose was developed based on in situ growth of TiO 2 nanowires on Ti 3 C 2 MXenes (TiO 2 –Ti 3 C 2 ) as the nanoplatform. Via tuning the alkaline oxidation time, different amount of TiO 2 nanowires can be found on MXenes. An ECL biosensor for glucose was constructed by covalent immobilization of glucose oxidase (GODx) on the glycine functional TiO 2 –Ti 3 C 2 surface, with the ECL signal depending on the in-situ formation of H 2 O 2 via the specifically catalysis of glucose by GODx, resulting in the apparent increase of ECL signal. The TiO 2 –Ti 3 C 2 can also act as the catalyst for the oxidation of H 2 O 2 into O 2 to enhance the ECL of luminol. Based on this strategy, a highly sensitive ECL biosensor for glucose was obtained in wide concentration range of 20 nM-12 mM with a low detection limit of 1.2 nM (S/N = 3). The synergistic effects of large surface area, excellent conductivity, and high catalytic activity of the TiO 2 –Ti 3 C 2 make the sensor highly sensitive toward glucose; the specific enzyme catalysis reaction promises excellent selectivity of the ECL sensor. The proposed biosensor has been employed to detect glucose in human serum, fruits, and sweat samples with excellent performance, providing a universal approach for glucose in various samples, which shows great prospect in clinical diagnostics and wearable sensors .