Amperometric ascorbic acid biosensor based on carbon nanoplatelets derived from ground cherry husks

In this work, a novel amperometric biosensor based on carbon nanoplatelets derived from ground cherry (Physalis peruviana) husks (GCHs-CNPTs) is reported for the sensitive and selective detection of ascorbic acid (AA). The structure of the nanoplatelets, the oxygen-containing groups and edge-plane-like defective sites (EPDSs) on the GCHs-CNPTs were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The presence of GCHs-CNPTs with a high density of EPDSs effectively enhances the electron transfer between AA and the glassy carbon electrode (GCE), and thus induces a substantial decrease in the overvoltage for AA oxidation compared with both a bare GCE and a GCE modified with carbon nanotubes (CNTs/GCE). In particular, an amperometric biosensor based on GCHs-CNPTs exhibited a wider linear range (0.01–3.57 mM), higher sensitivity (208.63 μA mM^? 1 cm^? 2), a lower detection limit (1.09 μM, S/N = 3) and better resistance to fouling for AA determination compared to a CNTs/GCE. The great potential of the GCHs-CNPTs/GCE for practical and reliable AA analysis was demonstrated by the successful determination of AA in samples taken from a medical injection dose and a soft drink.