Head-space analysis of samples was carried out as follows: 2
candies, cut crosswise into four parts (porphyrin based sensors)
or 1/16 candy corresponding to about 0.4 g (GNP–peptides based
sensors) were introduced in a 100 mL sealed glass laboratory bottle,
connected through the three-way stop-cocks to the N2 stream
(66 mL min1).