Ultrasensitive and highly selective sandpaper-supported copper framework for non-enzymatic glucose sensor

A simple and cost-effective sandpaper-supported copper framework (SSCF) was innovatively constructed by a novel “scribing-seeding-plating” approach and its application to non-enzymatic glucose determination was systematically investigated. The morphology, composition , crystalline structure of copper nanocoatings and sandpaper substrate were detailedly characterized with SEM, XPS, EDX and XRD, respectively. Processing parameters were optimized by central composite design to obtain an optimal conductivity of 4.69   ×   10 7   S·m −1 for copper nanocoatings. The SSCF exhibits excellent performance, with a wide linear range from 1.0   μM to 4.6   mM, a high sensitivity of 2165.5   μA   mM −1   cm −2 , a low determination limit of 30   nM (S/N   =   3), favorable selectivity and stability. The good electrocatalytic capacity could be attributed to the coordination between high-aspect-ratio porous microstructures of large surface area and copper nanocoatings of excellent catalytic ability. Finally, low relative standard deviations (1.59%–2.76%, n   =   10) and good recoveries (101.13%–102.69%) for enzymeless glucose determination in human serum samples and commercial drinks strongly validated satisfactory serviceability of SSCFs in medical diagnostics and food manufacturing.