3-Nitro-1,8-naphthalic anhydride is a reagent used to synthesize a monoboronic acid fluorescent sensor that exhibits emission suitable for ratiometric testing and also displays sensitivity for glucose relative to fructose and galactose. 3-Nitro-1,8-naphthalic anhydride is also used as a starting reagent in the synthesis of 5-substituted naphthalimide derivatives which exhibit high anti-cancer activity.