Through the use of preformed tetrathiafulvalene (TTF) particles and 7,7',8,8'-tetracyanoquinodimethane (TCNQ) microstructures as starting materials, the postchemistry of organic particles has been demonstrated for the first time in aqueous solution. The as-synthesized TTF-TCNQ nanowires show stable performance in organic nonvolatile memory devices with multiple write-read-erase-read cycles in air.