Surface-enhanced　Raman　scattering　(SERS)　has　been　used　for　trace　detection　at　the　single-molecule　level.　The　low-cost　preparation　of　high-performance　test　strips　has　enabled　the　development　of　SERS　techniques.　In　this　study,　oil-dispersible　metal　or　alloy　nanoparticles　prepared　by　the　Brust-Schiffrin　method　were　used　as　＂inks＂　in　a　ballpoint　pen　to　handwrite　SERS　test　strips　on　polytetrafluoroethylene　(PTFE)　membranes.　Because　of　the　good　PTFE　lipophilicity,　the　flexible　substrates　had　good　uniformity.　The　large　laser　damage　threshold　of　the　PTFE　membrane　also　enabled　increased　laser　powers　for　SERS　testing.　The　Au　and　Ag　alloy　nanoparticle　inks　exhibited　increased　performance　with　larger　proportions　of　Ag.　The　Au1Ag8　nanoparticles　had　the　best　properties,　and　those　strips　could　detect　10(-11)-M　Rhodamine　6G　dyes　in　a　10-mu　L　volume　with　an　enhancement　factor　of　5.4x10(8).　The　SERS　strips　were　used　to　demonstrate　detection　of　malachite　green,　the　use　of　which　is　prohibited　in　aquaculture　and　fish　tanks.