Furuzono et al.

100 nm100 nm100 nm

10 nm

10 nm10 nm

(a) (b) (c)

Fig. 1S TEM images of Ag nanoparticles prepared at different CDT concentrations: (a) CDT-Ag1; (b) CDT-Ag2 ; and (c) CDT-Ag3. The insets show higher magnification images.

Supplementary data:

Fig. 2S Antimicrobial activity of Ag nanoparticles coated with different concentrations of CDT against Escherichia coli. After mixing E. coli and Ag nanoparticles, indicated by CDT-Ag1-3, 20 µl of reactions were sampled at 0-2 hours shown at the top of each photo. Control means no addition of Ag materials, and free CDT means addition of CDT regent without Ag. Samples and seven ten-fold serial dilutions are illustrated by numbers ①～⑧ , for instance, each sample shown by should contain 1.4 x ①103 E. coli cells if no antimicrobial activities were presented.

Furuzono et al.

Control

CDT-Ag1

CDT-Ag2

CDT-Ag3

2.0 h1.0 h0.5 h0 h

Free-CDT

① ② ③ ④ ⑤ ~ ⑧ ① ② ③ ④ ⑤ ~ ⑧ ① ② ③ ④ ⑤ ~ ⑧ ① ② ③ ④ ⑤ ~ ⑧

Time

Dilution

Supplementary data:

Ag+Ag+

Ag+

Ag+

Ag+

Ag+

water

tolueneS COOH

S COOH

S COOH

Ag+

Ag+

water

tolueneS COOH

S COOH

S COOH

Ag+

Ag+

Ag+

Ag+

toluene

S

COOH

S COOH

SC

OO

H

Ag+

Ag+

Ag+

toluene

Ag S COOH

SC

OO

H

SC

OO

H

SHOOC

S

HOOC

S

COOH

S

COOH

S

HOOC

NaBH4

SCOOH

AgSHOOC S COOHSCOOH

SC

OO

H

SC

OO

HS

HOOC

S

HOOC

Furuzono et al.

Fig. 3S Schematic presentation of the synthesis mechanism of CDT-Ag nanoparticles by two-phase reduction system.

Ag ions in water phase were transferred into the oil phase by TOAB.

water water

CDTs were bonded with Ag ions.

Ag ions were reduced to metallic Ag.

Separation, evaporation and purification

CDT-Ag nanoparticle

TOAB CDT

S COOH Ag+

Ag ion

The solution mixtures were separated into two phases.

Supplementary data: