“…In the case of amine plasma treatments, to selectively probe -NH 2 groups, several reactants such as 4-trifluoromethyl-benzaldehyde (TFBA) [18,36,39,[55][56][57][58][59][60], pentafluoro-benzaldehyde (PFBA) [61,62], and para-chlorobenzaldehyde [63] have been used.…”