Four Schiff base copper (II) complexes derived from 1,3-bis(3-aminopropyl)tetramethyldisiloxane and 2-hydroxybenzaldehyde (H2L1), 3,5-di-bromo-2-hydroxybenzaldehyde (H2L2), 2-hydroxy-5-nitrobenzaldehyde (H2L3) and 5-chloro-2-hydroxybenzaldehyde (H2L4) were studied in terms of their biological and electrochemical application potentials. Thus, antimicrobial activity was evaluated against three fungi (Aspergillus flavus ATCC 20046, Penicillium chrysogenum ATCC 20044, Alternaria alternate ATCC 8741) from pure culture and two bacteria species (Pseudomonas aeruginosa ATCC 27813 and Bacillus sp. ATCC 31073). Among all the copper complexes investigated, the complex derived from 5-chlorosalicylaldehyde (CuL4) exhibit the highest biological activity. All the copper complexes have been investigated as possible active antioxidant enhancer for spirulina extract. Their redox behaviour was also investigated by running cyclic voltammetry measurements.