Graphene is a suitable transducer for wearable sensors because of its high conductivity, large specific surface area, flexibility, and other unique considerable features. Using a simple, fast galvanic pulse electrodeposition approach, a unique nonenzymatic glucose amperometric electrode was successfully developed based on well-distributed fine Cu nanoparticles anchored on the surface of 3D structure laser-induced graphene. The fabricated electrode allows glucose detection with a sensitivity of 2665 μA/mM/cm2, a response time of less than 5 s, a linear range of 0.03–4.5 mM, and a LOD of 0.023 μM. It also detects glucose selectively in the presence of interfering species such as ascorbic acid and urea. These provide the designed electrode the advantages for glucose sensing in saliva with 97% accuracy and present it among the best saliva-range non-enzymatic glucose sensors reported to date for real-life diagnostic applications.

A nonenzymatic laser-induced flexible amperometric graphene electrode for glucose detection in saliva
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 LIG Design and fabrication
        2.3 Pulsed current deposition of Cu NPs on LIG
        2.4 Morphological and structural characterizations
        2.5 Electrochemical characterization
        2.6 Glucose sensing in serum and saliva
    3 Results and discussion
        3.1 Lasing of PI
        3.2 Morphology and structure characterization of LIG
        3.3 LIG modification by CuNPs using pulse current deposition (PCD)
        3.4 Electrochemical characterization of CuNPs-LIG electrode
        3.5 Electrocatalytic oxidation of glucose
        3.6 Amperometric responses of the CuNPs-LIG electrode toward glucose oxidation
        3.7 Detection of glucose in actual biological saliva samples
        3.8 Detection of glucose in actual biological saliva samples
        3.9 Flexibility and wettability of the electrode
    4 Conclusion
    Acknowledgements 
    References

• Betty Edem Nugba(Biotechnology Program, Institute of Basic and Applied Sciences, Egypt-Japan University of Science and Technology, Borg Al Arab City, P.O. Box 179, Alexandria, Egypt, Graphene Center of Excellence for Energy and Electronics Applications, Egypt-Japan University of Science and Technology, Borg Al Arab City, P.O. Box 179, Alexandria, Egypt)
• A. A. El‑Moneim(Graphene Center of Excellence for Energy and Electronics Applications, Egypt-Japan University of Science and Technology, Borg Al Arab City, P.O. Box 179, Alexandria, Egypt, Nanoscience Program, Institute of Basic and Applied Sciences, Egypt-Japan University of Science and Technology, Borg Al Arab City, P.O. Box 179, Alexandria, Egypt)
• Nahla O. Mousa(Faculty of Science, Cairo University, Giza, Egypt)
• Ahmed Osman(Biotechnology Program, Institute of Basic and Applied Sciences, Egypt-Japan University of Science and Technology, Borg Al Arab City, P.O. Box 179, Alexandria, Egypt)