Additional file 1 of Ligand-modulated synthesis of gold nanoclusters for sensitive and selective detection of folic acid

Additional file 1: Supplementary information. Figure S1. Synthesis schematic illustration of AuNCs capped with D-Trp, D-Trp-OBzl, D-Trp-OMe and 1-Me-D-Trp, respectively. Figure S2. (A) Photographs of AuNCs capped with D-Trp (a), D-Trp-OMe (b), D-Trp-OBzl (c) and 1-Me-D-Trp (d) from left to right under daylight (upper row) and 365 nm UV irradiation (bottom row); (B) Fluorescence emission spectra of D-Trp@AuNCs (a), D-Trp-OMe@AuNCs (b), D-Trp-OBzl@AuNCs (c) and 1-Me-D-Trp@AuNCs (d). Figure S3. Fluorescence emission spectra of D-Trp-OMe@AuNCs (A), D-Trp-OBzl@AuNCs (B), 1-Me-D-Trp@AuNCs (C) and D-Trp@AuNCs (D) in the absence and presence of FA (a: 0.0 μM; b: 25.0 μM; c: 75.0 μM). Figure S4. The zeta potential difference of AuNCs in the absence and presence of FA: 1. D-Trp-OMe@AuNCs, 2. D-Trp-OBzl@AuNCs, 3. 1-Me-D-Trp@AuNCs and 4. D-Trp@AuNCs; where Z0 and Z are the potentials of AuNCs in the absence and presence of FA, respectively. Figure S5. Effects of concentrations of D-Trp (A), HAuCl4 (B), synthesis time (C) and synthesis temperature (D) on relative fluorescence intensity of the fluorescent probe. Figure S6. XPS spectra of Au 4f of D-Trp@AuNCs (A) and D-Trp@AuNCs-FA (B). Figure S7. FT-IR spectrum of D-Trp (a) and D-Trp@AuNCs (b). Figure S8. (A) Stern-Volmer plot of fluorescence quenching; (B) Fluorescence lifetime of D-Trp@AuNCs in the absence and presence of FA. Figure S9. The zeta potential of D-Trp@AuNCs, FA and D-Trp@AuNCs-FA (pH 7.0). Figure S10. Effects of pH (A); NaCl concentration (B) and incubation time (C) on F/ F0. Figure S11. Stability of the prepared D-Trp@AuNCs. Table S1. Comparison with the reported AuNCs for detection of FA

附加文件1：补充资料。图S1：分别以D-色氨酸（D-Trp）、D-色氨酸苄酯（D-Trp-OBzl）、D-色氨酸甲酯（D-Trp-OMe）及1-甲基-D-色氨酸（1-Me-D-Trp）包覆的金纳米簇（AuNCs）的合成示意图。图S2：(A) 从左至右依次为D-Trp包覆的AuNCs（a）、D-Trp-OMe包覆的AuNCs（b）、D-Trp-OBzl包覆的AuNCs（c）及1-Me-D-Trp包覆的AuNCs（d）在日光下（上排）与365 nm紫外照射下（下排）的实物照片；(B) D-Trp@AuNCs（a）、D-Trp-OMe@AuNCs（b）、D-Trp-OBzl@AuNCs（c）及1-Me-D-Trp@AuNCs（d）的荧光发射光谱。图S3：分别在无叶酸（FA）及添加不同浓度叶酸（a：0.0 μM；b：25.0 μM；c：75.0 μM）时，D-Trp-OMe@AuNCs（A）、D-Trp-OBzl@AuNCs（B）、1-Me-D-Trp@AuNCs（C）及D-Trp@AuNCs（D）的荧光发射光谱。图S4：有无叶酸存在时金纳米簇的zeta电位差：1. D-Trp-OMe@AuNCs、2. D-Trp-OBzl@AuNCs、3. 1-Me-D-Trp@AuNCs及4. D-Trp@AuNCs；其中Z0与Z分别代表无叶酸及有叶酸存在时金纳米簇的电位。图S5：D-Trp浓度（A）、氯金酸（HAuCl4）浓度（B）、合成时间（C）及合成温度（D）对该荧光探针相对荧光强度的影响。图S6：D-Trp@AuNCs（A）与D-Trp@AuNCs-FA（B）的Au 4f区X射线光电子能谱（XPS）。图S7：D-Trp（a）与D-Trp@AuNCs（b）的傅里叶变换红外光谱（FT-IR）。图S8：(A) 荧光猝灭的斯特恩-沃尔默（Stern-Volmer）曲线；(B) 有无叶酸存在时D-Trp@AuNCs的荧光寿命。图S9：pH 7.0条件下，D-Trp@AuNCs、FA及D-Trp@AuNCs-FA的zeta电位。图S10：pH值（A）、氯化钠（NaCl）浓度（B）及孵育时间（C）对F/F0的影响。图S11：所制备D-Trp@AuNCs的稳定性。表S1：本研究与已报道的用于叶酸检测的金纳米簇相关研究对比。