1. A method for detecting ferric ions from a sample, the method comprising:

providing a sample suspected of containing one or more ferric ions; and

contacting the sample with a composition to form a mixture, wherein the composition comprises one or more polyanthrylenes,

wherein the one or more polyanthrylenes each independently comprises at least two monomer units each independently represented

by a formula selected from the group consisting of Formula I, Formula II, Formula III, Formula IV, Formula V, Formula VI,

Formula VII, Formula VIII, Formula IX, Formula X, Formula XI, Formula XII, Formula XIII, Formula XIV, Formula XV, Formula

XVI, Formula XVII, and any combination thereof:

wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, R34, R35, R36, R37, R38, R39, R40, R41, R42, R43, R44, R45, R46, R47, R48, R49, R50, R51, R52, R53, R54, R55, R56, R57, R58, R59, R60, R61, R62, R63, R64, R65, R66, R67, and R68are each independently hydrogen or an electron donating group,

wherein at least one monomer unit in the one or more polyanthrylenes is not represented by Formula I;

exposing the mixture to a radiation effective to produce fluorescence from the mixture;

measuring the amount of fluorescence produced by exposing the mixture to the radiation; and

determining the presence or absence of ferric ions in the sample based on the amount of fluorescence measured.