A novel 2D porous Zr(IV)-based metal-organic framework (USTS-7) was assembled from 2,5-bis[2-(methylthio)ethylthio] terephthalic acid and ZrCl4. USTS-7 retains its stability in water, strong acid, and base; moreover, it is highly luminescent and displays a remarkable selective sensing property toward Cr2O72- in aqueous solution with a very low detection limit.