Comparison of Insulin Determination on NiNPs/chitosan- MWCNTs and NiONPs/chitosan-MWCNTs Modified Pencil Graphite Electrode - Šišoláková, Ivana (University of P.J. Šafárik in Košice. Department of Physical Chemistry) ; Hovancová, Jana (University of P.J. Šafárik in Košice. Department of Physical Chemistry) ; Oriňaková, Renáta (University of P.J. Šafárik in Košice. Department of Physical Chemistry) ; Oriňak, Andrej (University of P.J. Šafárik in Košice. Department of Physical Chemistry) ; Rueda García, Daniel (Institut Català de Nanociència i Nanotecnologia) ; Shylenko, Oleg (University of P.J. Šafárik in Košice) ; Radoňák, Jozef (University of P.J. Šafárik in Košice)