Several　thioether　linked　bichromophoric　squaraines　1　were　prepared　and　characterized.　Among　these,　the　bichromophore　1c,　containing　three　sulfur　atoms,　was　found　to　selectively　bind　with　Ca2+　and　lead　to　a　folded　conformation.　The　selective　binding　of　Ca2+　resulted　in　an　absorption　blue　shift　and　fluorescence　quenching　due　to　the　cation-induced　folding　of　the　bichromophore　and　the　resultant　exciton　coupling　between　the　squaraine　chromophores.　Job＇s　plot　confirmed　a　1:1　binding　between　1c　and　Ca2+.　Anions　such　as　oxalate　can　extract　Ca2+　from　squaraine　foldamers　via　the　formation　of　insoluble　salts　and　restore　the　fluorescent　signal.　This　sensing　approach　can　be　applied　to　the　＇turn　on＇　fluorescent　detection　of　oxalate　with　a　low　detection　limit　of　5.2　nM　(3σ/k).　©　2014　Elsevier　B.V.　All　rights　reserved.