Furthermore, the evident fluorescence quenching of JUC-557-nanosheet allowed visual trace detection of different analytes based on a handheld UV lamp. JUC-557-nanosheet can be easily prepared into various shapes of luminous patterns (Supplementary Fig. ). A single-crystal silicon wafer drop-coated with JUC-557-nanosheet as a facile visual fluorescence sensing platform was utilized to detect different analytes, including Fe 3+ (0.01 M), I 2 (0.005 M), NB (0.0005 M), and TNT (0.0005 M). Our naked eyes could quickly identify the visible fluorescence disappearance of sensing wafers upon the titration of different analytes could be quickly identified with naked eyes (Supplementary Fig. ), which demonstrates that such fluorescence materials have a promising potential in practical trace pollutant analysis.