Predicted centimetre luminosities and fluxes versus the bolometric luminosities of SUCANES objects. Left: 3.6 cm luminosities of substellar candidates with L_int < 0.2 L_⊙, and with an estimated L_bol in SUCANES (cyan circles). The 3.6 cm luminosities were derived using the correlation (blue dashed line) derived by Anglada et al. (2018) for YSOs (orange squares). We mark the proto-BD candidates studied by Morata et al. (2015) with green squares. Right: estimated 3.6 cm flux densities of the SUCANES objects included in the left panel, using the distances included in our database. The grey lines represent the rms in µJy/beam (dashed) and the 5-σ estimation (solid) from the JVLA observations included in Morata et al. (2015). The magenta and green lines are the expected sensitivities of the ngVLA and SKA-mid facilities, respectively, after six minutes of on-source exposure time. The dashed and solid lines represent the rms (in µJy/beam) and 5-σ estimations, respectively. The data points are colour-coded depending on their distances (see colour bar). The dotted lines represent objects at 140 pc (blue) and 600 pc (light green), revealing that ngVLA will be sensitive to very faint proto-BD candidates with L_bol~10⁴ L_⊙ and 10² L_⊙ at these distances, respectively.