Fabrication and evaluation of a carbon quantum dot/gold nanoparticle nanohybrid material integrated onto planar micro gold electrodes for potential bioelectrochemical sensing applications

We have developed a hybrid nanomaterial based on both of carbon quantum dots(CQDs)/gold nanoparticles( AuNPs), such that the cheapness and versatility on the CQDs is directly combined with the inertness and electrochemical activity of the AuNPs to create a new electrochemical biosensor. Here, for the first time, we demonstrate how this interesting materials combination can be applied in the development of an enzymatic biosensor that is easily manufacturable using standard semiconductor processing methods. To demonstrate the potential and performance of the CQDs as an immobilization matrix, glucose oxidase(GOx) enzyme was chosen as a model system. The analytical performance of the developed biosensor was examined using chronoamperometry and the developed CQDs/AuNPs-GOx biosensor exhibited a sensitivity of 47.24 mu A mM(-1) cm(-2) and a detection limit of 17 mu M (S/N = 3) with a linear response to glucose ranging from 0.05 mM to 2.85 mM (R = 0.987). Furthermore, this new biosensor showed a high level of reproducibility and was also shown to be very selective towards glucose in the presence of the possible interference species ascorbic acid, uric acid and acetaminophen. Finally, it is demonstrated that the sensor is also capable of reliably detecting glucose levels in human serum. (c) 2018 Elsevier Ltd. All rights reserved.