Enhanced fluorescence quenching of hemin detected by a novel polymer of curcumin† Bedanta Gogoi and Neelotpal Sen Sarma* Electronic Supplementary Information (ESI) Preparation of curcumin methacrylate: Methacrylic acid and benzoyl chloride are mixed in 1:2 molar ratios and the mixture is distilled at its boiling point in a round bottom flask in presence of small amount of hydroquinone. The distilled product is collected in a collector at ice cool temperature. This product is the required methacryloyl chloride and is redistilled for further purification. To prepare curcumin methacrylate 1 g mol of curcumin is dissolved in ethyl methyl ketone in a two necked round bottom flask. 2 g mol of methacryloyl chloride along with 25 ml of ethyl methyl ketone are added drop wise into the flask with continuous stirring in an ice bath. 1.1 g mol of triethyl amine is then added to this reaction mixture to neutralize the acid produced in the reaction. After about 4 hours the mixture solution is filtered and the precipitate is washed with Milli pore water and further by 0.1 N NaOH solution. The organic layer produced after filtration is separated by a separating funnel. The dissolved product curcumin methacrylate is obtained by heating the viscous solution to about 100 o C. The product is washed with methanol and Milli pore water to remove impurities. Results of EDX and GPC measurements: From EDX measurements with the help of Carl Zeiss Ʃigma VP using EHT 20kV, we determined the percentage composition of the polymer. It is observed that the results of repeating EDX record are very close to each other i.e. the element percentage are almost same. The EDX spectrum of the polymer is shown in supplementary figure S1 A and the percentage of elements are given in supplementary figure S1 B. We did not find unnecessary elements like N, Cl etc, which are generally detected under EDX measurements. The molecular weight distribution is determined in THF by three column GPC system (WATERS 2414). The distribution curve obtained from GPC measurements and the molecular weights of the polymer are given in supplementary figure S1 C and D respectively. The molecular weight distribution is only two and both of the fragments possess a unit polydispersity index (PDI), i.e. only one monomer constitutes the whole polymeric structure. Supplementary Figure S1: A. SEM-EDX plot, B. % distribution of elements in sulfonated polymer of curcumin, C. GPC distribution plot for the polymer and D. GPC Results. Element Weight% Atomic % C 76.06 81.77 O 21.23 17.14 S 2.81 1.09 Total 100 B C A D Electronic Supplementary Material (ESI) for RSC Advances This journal is © The Royal Society of Chemistry 2013