This invention relates to a A compound (L) for primary detection of zinc ions (Zn 2+) ions represented by formula (I) X-N=CH-R wherein, X is a hexose sugar moiety and R is a 2-hydroxy-1 -naphthyl. This invention also to the methods for selective detection of Zinc ions (Zn2+) and phosphate.[IN-MUM-2011-01653A]