Patent ID: 8729276

Claim:
A cyanine compound represented by Formula 1 below: wherein R 1 and R 1 ′ are each independently hydrogen, a sulfonic acid group or a sulfonic acid base; R 2 , R 2 ′, R 3 and R 3 ′ are each independently hydrogen or a C 1 -C 6 alkyl group; R 4 is hydrogen, a C 1 -C 6 alkyl group, a carboxyl group, —CONH(CH 2 ) L SO 2 CH═CH 2 , —CONH-para-(C 6 H 4 )SO 2 CH═CH 2 or —CONH-meta-(C 6 H 4 )SO 2 CH═CH 2 ; B is (CH 2 ) l , para-(C 6 H 4 ) or meta-(C 6 H 4 ); m and m′ are each independently an integer of 1 to 5; and L, l and n are each independently an integer of 1 to 5.