Optimization of the immobilization of bacterial spores on glass substrates with organosilanes (Phys. Status Solidi A 6∕2016)

Bacterial spores are suitable for use as detectors to recognize microorganisms (e.g., bacteria, viruses) or evaluate aseptic processing due to their ability to sense environmental changes and survive prolonged harsh conditions (e.g., high temperature, extreme pH levels). In their publication on pp. 1463–1470, Julio Arreola et al. immobilized Bacillus atrophaeus DSM 675 endospores with organosilanes on glass substrates, which were used as a model system for spore-based biosensors. Two different organosilanes were investigated for the immobilization of the spores: (3-glycidyloxypropyl) trimethoxysilane (GPTMS) and (3-aminopropyl)triethoxysilane (APTES), whereas, a third one was used to inhibit the attachment of the spores to the substrate: 1H,1H,2H,2Hperfluorodecyltriethoxysilane (PFDTES). For the immobilization, the authors systematically optimized different parameters involved in the silanization process, that is, the nature of the solvent, concentration of the silane, silanization time, curing process and silanization temperature. The silanized glass substrates were further characterized by atomic force microscopy and contact angle measurements. These protocols may potentially be useful towards the specific and robust immobilization of spores on biosensors.