A fluidic device (100) is described for locally coating an inner surface of a fluidic channel. The fluidic device (100) comprises a first (101), a second (102) and a third (103) fluidic channel intersecting at a common junction (105). The first fluidic channel is connectable to a coating fluid reservoir and the third fluidic channel is connectable to a sample fluid reservoir. The fluidic device (100) further comprises a fluid control means (111) configured for creating a fluidic flow path for a coating fluid at the common junction (105) such that, when coating, a coating fluid propagates from the first (101) to the second (102) fluidic channel via the common junction (105) without propagating into the third (103) fluidic channel. A corresponding method for coating and for sensing also has been disclosed.