“…Composite sorbents for the solid-phase extraction of metal ions [ 4 , 5 ], pesticides and insecticides [ 6 , 7 ], pharmaceutical substances [ 8 ], and toxins [ 9 , 10 ] with higher selectivity to target components compared to traditional synthetic and natural polymers have been proposed. Composite matrices are used in various chemical sensors, the response of which can be both electrochemical [ 11 , 12 ] and optical [ 13 , 14 ]. For example, for holographic sensor films and photonic crystals [ 15 , 16 , 17 ], swelling causes shifts in their Bragg diffraction, and the effective refractive index of the film also changes.…”