Question

it is not easy to detect nutrinos.explain

Answer 1

first of all we look their properties
spin:1/2
mass: 0
charge:0
we also know detector work by measuring interaction of the particle with the actual material , that composes the detector . what we have here, is a particle that doesn't interact electromagnetic interaction . it is hard to perceive but everything around you happen basically because of the electromagnetic interaction with a little bit of gravity .but nutrinos don't have that . so we have only choice that is weak interaction option, that is really weak in case of nutrinos .
so, it is hard to detect nutrinos.