Microparticulate films of a canthin-6-one alkaloid (L), a natural beta-carboline alkaloid presenting a characteristic naphtyridone motif, on glassy carbon electrodes yield different, separate voltammetric signals for dsDNA, ssDNA, G-quadruplex DNA, different degrees of DNA methylation and the biomimetic nucleosomal DNA with detection limit of 10(-5) M. This multiple-signal electrochemical behavior is in contrast with conventional use of DNA intercalators, only discriminating between different DNA forms by variations in the intensity of a unique signal. Complementary photochemical and scanning electrochemical microscopy (SECM) data suggest that the differences in the voltammetric response of the different DNA forms derive from the intercalating properties of the canthin-6-one. (C) 2013 Elsevier Ltd. All rights reserved.