Proteins　are　among　the　pivotal　constituents　in　living　systems.　The　development　of　fluorescent　probes　with　appropriate　selectivity　and　sensitivity　at　biologically　relevant　signaling　levels　offers　opportunities　to　explore　their　roles　in　physiological　functions.　Here　we　report　the　design　and　synthesis　of　a　new　squaraine　based　fluorescent　molecule　SQ1　and　the　study　of　its　sensing　interaction　with　bovine　serum　albumin　(BSA).　The　interaction　of　SQ1　with　BSA　was　investigated　by　fluorescence　and　UV–vis　absorption　spectroscopy.　Displacement　studies　were　carried　out　with　site　selective　probes　to　locate　the　binding　site,　showing　that　the　SQ1　binds　at　site　I.　The　results　obtained　from　the　docking　studies　are　also　in　good　agreement　with　the　experimental　results.　The　SQ1⊂BSA　was　used　for　cell　incubation　and　in　vitro　fluorescence　imaging　studies.　©　2017　Elsevier　B.V.