Ag-Doped CuO Microflowers on Multilayer Graphene for a Highly Sensitive Non-Enzymatic Glucose Sensor

In situ synthesis of Ag-doped CuO microflowers on multilayer graphene (MLG) and their application in non-enzymatic detection of glucose are studied here. Mechanically exfoliated MLG has particular advantages such as low defects and cost efficiency. However, the deposition of CuO on its surface is still a challenge due to the lack of active sites on the MLG surface. In this work, a one-step chemical bath deposition approach is developed to synthesize homogeneous CuO microflowers and Ag-doped CuO microflowers on MLG surfaces. The CuO structures are composed of ultra-small CuO nano-spindles and internal nano-gaps. The materials are well characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive spectrometry (EDS) and evaluated as glucose sensors. The electrode of Ag-doped CuO microflowers on MLG exhibits a sensitivity of 1527 mu A mM(-l) cm(-2) in a linear response range of 0.01 mM similar to 6.0 mM with an excellent selectivity and a long-term stability. The composite is a promising material for glucose sensors due to its facile synthesis and highly detective performance.