Nickel oxide nanoparticles of about 6 nm were obtained in two simple steps. Nanoparticles were characterized by using FTIR spectroscopy, TEM images, thermal analysis, X-ray diffraction and electrochemical techniques. GCEs were modified with nanoparticles by the casting method and their sensing properties were optimized. Electrochemical tests confirmed their excellent electrocatalytic properties, which are able to detect glucose, fructose, lactose and sucrose. Under optimized conditions NiO NPs-modified sensors showed a good sensitivity of about 3.06 A M1 cm2 (R2:0.999), linear range up to 0.6 mM, a fast time response (ca. 3 s) with a limit of detection of 0.39 μM. Their selectivity was tested for common interferences with promising results. The application of the sensor in real samples was evaluated by determining the total sugar content in different commercial beverages with recoveries of about 100%.
