A BrPAPS based Cu 2+ complex has been developed as a colorimetric probe for the selective recognition of homocysteine (Hcy) over cysteine (Cys) and glutathione (GSH) in an aqueous solution via indicator displacement assay. formed with 1:1 ratio (BrPAPS-Cu ) accompanied by color change from yellow to red. Detecting Hcy is on high affinity . The addition BrPAPS-Cu caused formation 2:1 stoichiomet...