Open-air plasma jets are becoming increasingly popular due to easy and affordable large-scale coating deposition on diverse substrates. However, direct deposition of primary amine groups (NH 2 ), which are attractive as covalent anchor points for molecule grafting, remains challenging. In this study, 3-aminopropyltrimethoxysilane (APTMS) has been directly polymerized on glass by a plasma jet. Quantification of NH 2 showed that APTMS polymerization and NH 2 degradation were correlated with Yasuda's parameter and that a compromise between NH 2 retention and coating stability is required. Evaporation of APTMS was found to improve surface smoothness and homogeneity but was found to decrease the deposited NH 2 concentration, from 3.7 ± 1.3 NH 2 /nm 2 to three times lower. Results showed that deposited NH 2 could be used as anchor points for polyethylene glycol chain immobilization.