Gangaiah Mettela 1, Radha Boya 1, Danveer Singh 2, G. V. Pavan Kumar 2, G. U. Kulkarni 1 *

Size: px

Start display at page:

Download "Gangaiah Mettela 1, Radha Boya 1, Danveer Singh 2, G. V. Pavan Kumar 2, G. U. Kulkarni 1 *"

Cecily Mosley
5 years ago
Views:

1 1 Supplementry Informtion for Highly tpered pentgonl ipyrmidl Au microcrystls with high index fceted corrugtion: Synthesis nd opticl properties Gngih Mettel 1, Rdh Boy 1, Dnveer Singh 2, G. V. Pvn Kumr 2, G. U. Kulkrni 1 * 1 Chemistry nd Physics of Mterils Unit nd DST Unit on Nnoscience, Jwhrll Nehru Centre for Advnced Scientific Reserch, Jkkur P. O., Bnglore 56 64, Indi 2 Photonics nd Opticl Nnoscopy Lortory, Deprtment of Physics nd Chemistry, Indin Institute of Science Eduction nd Reserch (IISER), Pune 4118, Indi Tle S1. Literture reports for the synthesis of Au rice/ipyrmidl structures... 2 S1. SEM imges of Au polygons... 2 S2. SEM imge nd EDS spectrum of AgBr crystls... 3 S3. Digitl cmer photogrphs of solutions... 3 S4. Steps involved in the µ-cpbs synthesis... 4 S5. Aspect rtio histogrm... 5 S6. AFM imges of µ-cpbs... 5 S7. Opticl microscope imges of µ-cpbs... 5 S8. TGA of AuAgToABr Tle S2. Angulr reltion etween {1} nd {hk} fcets... 7 Tle S3. Micro fcet nottion of high index fcets S9. EDS mpping nd XPS spectr from µ-cpbs... 8 S1. SEM imges of Au nnoprticles otined fter 3 min thermolysis... 8 S11. Histogrm shows µ-cpbs growth s function of time... 9 S12. SEM imges of µ-cpbs with nd without pentgonl strs... 9 S13. XRD pttern nd polrizing microscopy imges from ToABr nd its metl complexes... 1 S14. Enhncement fctor clcultion nd pick nd proe experiment.. 11 S15. Asorption spectrum of µ-cpbs.13 * Correspondence nd requests for mterils should e ddressed to G. U. K (kulkrni@jncsr.c.in)

No Shpe Approximte Reference length (nm) 1 Au ipyrmids 75 1 2 Au ipyrmids 1 2 3 Au/Ag lloy ipyrmids 4-9 3 4 Au ipyrmids 2 4 5 Au ipyrmids 75 5 6 Au ipyrmids 1 6 7 Au ipyrmids

2 2 Tle S1: Literture reports for the synthesis of Au rice/pentgonl ipyrmidl structures. S.No Shpe Approximte Reference length (nm) 1 Au ipyrmids Au ipyrmids Au/Ag lloy ipyrmids Au ipyrmids Au ipyrmids Au ipyrmids Au ipyrmids Au ipyrmids Ag nnorice Au ipyrmids Au ipyrmids Au ipyrmids Au ipyrmids, rnched Au structures Au nnorice Au nnorice Fe 2 O 3 /Au core shell ipyrmidl 4 16 structures 17 Au ipyrmids Au ipyrmids Au ipyrmids A) 1 µm 1 µm Figure S1. A, Low mgnifiction SEM imge of Au polygons otined y the thermolysis of AuToABr (without Ag) t 135 C., A mgnified imge of polygon.

3 Ag L Br K 1 2 3 4 5 X-Ry energy (kev) 5 µm Figure S2. SEM imge of the product otined y the thermolysis of AgToABr (without Au) t 135 C for 11 hrs.

Photogrphs showing the optimized conditions for complete trnsfer of metl ions from queous to orgnic lyer.

3 3 Ag L Br K X-Ry energy (kev) 5 µm Figure S2. SEM imge of the product otined y the thermolysis of AgToABr (without Au) t 135 C for 11 hrs. EDS spectrum collected from crystl confirms tht the product is AgBr. c d Pink solution Ple Light ple colorless pink solution pink solution Aq2 : Org2 Aq2 : Org4 Aq2 : Org5 Aq2 : Org6 Figure S3. Photogrphs showing the optimized conditions for complete trnsfer of metl ions from queous to orgnic lyer. In order to understnd the metl nion phse trnsfer efficiency of ToABr, titrtion of the leftover metl nion in queous phse ws performed y NBH 4 reduction. Metl slt (HAuCl 4, AgNO 3 ; 25mM) nd ToABr (5 mm) solutions were prepred in wter (q) nd toluene (org) respectively. To find out the desired volume of ToABr solution for trnsferring metl nions from 2 ml of queous solution (i.e., 3:1 of Au(III), Ag(I)), vrious volumes of ToABr were tried out. Aqueous nd orgnic solutions were mixed nd stirred for 1 h. During stirring, the colorless orgnic lyer turned to red. After stirring, queous phse ws seprted out nd NBH 4 (1 ml, 5 mm) solution ws dded. The reduction of metl ions to metl nnoprticles leds to color chnge of the queous phse which cn e used to estimte if the metl nion got completely trnsferred to the orgnic phse. From Fig. S3d, it is understndle tht the metl ion trnsfer ws quite successful with volume rtio of 1(q) : 3(org).

4 AuAgToABr 3D-shpes 135 C Toluene wsh AgBr c 2.5k 2.k 1.5k *(2) #(111) * AgBr # Au µ-cpb 2 µm 1.k 5.

3 4 5 6 2 (Degree) 7 8 Figure S4., Schemtic illustrtes the steps involved for µ-cpbs synthesis.

4 4 AuAgToABr 3D-shpes 135 C Toluene wsh AgBr c 2.5k 2.k 1.5k *(2) #(111) * AgBr # Au µ-cpb 2 µm 1.k (Degree) NH 3 wsh *(22) #(22) #(311) #(2) *(222) *(4) d 1.k e 8.k (111) Au 5 µm 6.k 4.k 2.k (2) (22) (311) (Degree) 7 8 Figure S4., Schemtic illustrtes the steps involved for µ-cpbs synthesis. SEM imges nd XRD ptterns efore ( nd c) nd fter (d nd e) NH 3 wshing. A comprison of diffrction pek intensities of µ-cpbs with those of polycrystlline Au from JCPDS: ). S.No Au plne JCPDS (65-287) µ-cpbs Difference (%) 1 (111) (2) (22) (311)

Height (nm) No of prticles (%) 5 4 35 3 25 2 15 1 5 6

A histogrm of the vrition in the spect rtio of long

8 6 4 2 c 5 µm 2 4 6 8 Distnce ( m) 2 nm Figure S6.

5 Height (nm) No of prticles (%) Aspect rtio Figure S5. A histogrm of the vrition in the spect rtio of long structures (µ-cpbs) c 5 µm Distnce ( m) 2 nm Figure S6. -, AFM topogrphy of µ-cpb nd the z-profile mesured long the dotted line. c, Averge roughness t 1 nd 2 is 1.45 nd 1.16 nm respectively. Figure S7. -, Opticl microscopy imges of µ-cpbs t different mgnifictions.

6 Weight (%) I 6 4 II 2 III Temperture ( C) Figure S8. TGA plot showing vrious stges (I-III) of decomposition of the precursor. The decomposition strts t ~16 C nd the weight loss occurs in three steps - region I (2.46%;1 mole of ToA, Cl 2 nd Br 2 ), regions II (53.61%;3 moles of ToA, 2 moles of n-octyl romide, Cl 2 or HBr) nd region III (12.31%; 1 mole of ToA) corresponding respectively to solvent evportion, AuAgToABr decomposition, desorption of ToA, nd Cl -, nd the metllic residue. Mjority of the weight loss is due to the removl of the ToA nd it occurs in the rnge of 15 3 C 2. The decomposition of the precursor my occur s follows. (AuCl 4 ) (AgBr 2 ) ToABr Au + AgBr + ToA (Trioctylmine) + (Cl, Br ) (1) ToABr ToA + n-octylromide (2) The residue ws 13.6 wt% which is composed of metllic Au nd AgBr (supported y Figure S4). Bsed on TGA, the derived formul is (AuCl 4 ) (AgCl 2 ).4ToABr, which in simplified wy, is written s AuAgToABr.

7 7 Fcet-I Fcet-II Mesured ngle ( ) Theoriticl ngle ( ) {73} {61} {21} {91} {1} {61} {1} {73} {1} {91} {1} {21} Tle S2. Angulr reltion etween vrious fcets. Fcet Nottion {61} Au(S)-[6(1)x1(11)] {21} Au(S)-[2(1)x1(11) {91} Au(S)-[9(1)x1(11) {73} Au(S)-[1(52)x1(21)] Tle S3. Micro fcet nottion of vrious fcets. Fcet nottion is done sed on ref 21. For Miller indices (n1), n(1)x(11) is the nottion. The contriution of {1} is predominte in constructing {hk} type high index plnes. 21

8 c 2.5k 2.k 1.5k 1.k 5. 4 3 2 1 Si K Ag3d 3/2 Au M Au M 1µm Ag L 1µm.

energy (ev) Figure S9., EDS spectrum collected from µ-cpb. EDS mps otined for Au M nd Ag L levels re shown in the insets.

8 8 c 2.5k 2.k 1.5k 1.k Si K Ag3d 3/2 Au M Au M 1µm Ag L 1µm X-ry energy (kev) Ag3d 5/2 3k Au4f 5/2 Au4f 7/2 2k 2k 1k Binding energy (ev) d 15 Br 3d Binding energy (ev) Binding energy (ev) Figure S9., EDS spectrum collected from µ-cpb. EDS mps otined for Au M nd Ag L levels re shown in the insets. Core level photoelectron spectr in the regions of () Au 4f, (c) Ag 3d, (d) Br 3d. The µ-cpbs otined with Au(III):Ag(I) of 75:25. The C1s (284.4 ev) signl ws used for energy clirtion. 2 nm 1 nm Figure S1. -, SEM imges collected t different mgnifictions fter 3 min thermolysis. Irregulr shped Au nnoprticles with 2-3 nm were oserved.

CPBs length ( m) 9 24 2 16 12 8 4.6.4.2. 3 6 9 12 3 6 9 12 15 18 Time (min) 3 42 54 72 Min. Mx.

The dt from the 3-12 minutes period is mgnified nd shown in the inset.

-, SEM imges of µ-cpbs without nd with pentgonl strs.

9 CPBs length ( m) Time (min) Min. Mx. Avg. Figure S11. Histogrm representing µ-cpbs growth s function of time. The dt from the 3-12 minutes period is mgnified nd shown in the inset. Error rs represent stndrd devition in the length of µ-cpbs. C Figure S12. -, SEM imges of µ-cpbs without nd with pentgonl strs. Schemtics show pentgonl tip without nd with petls. c, Mgnified SEM imge of ridges mrked in ().Ridges grown long the <112> directions re the corrugted structures from the top view of the µ-cpbs. Scle r is 2 nm.

1 1k 8k T=ToABr 3k 25k * AuToABr 6k 4k 2k 2k 15k 1k 5k 2 mm c 8k 6k 5k 3k 2k 8 16 24

5k # AuAgToABr 4k T 3k T / # 2k * 2 mm * T 1k T / # * T T T T * * 8 16 24 32 4 2

XRD ptterns collected from ) ToABr, ) AuToABr, c) AgToABr nd d) AuAgToABr films (T,

10 1 1k 8k T=ToABr 3k 25k * AuToABr 6k 4k 2k 2k 15k 1k 5k 2 mm c 8k 6k 5k 3k 2k (Degree) # AgToABr 2 mm (Degree) d (Degree) 6k 5k # AuAgToABr 4k T 3k T / # 2k * 2 mm * T 1k T / # * T T T T * * (Degree) Figure S13. XRD ptterns collected from ) ToABr, ) AuToABr, c) AgToABr nd d) AuAgToABr films (T, ToABr; #, AgToABr; *, AuToABr). Insets: polrizing microscopy imges of the films. In the imge shown in d, the gry region is AgToABr nd the red region, AuToABr.

11 Enhncement fctor is clculted y using eqution (1) EF=(I SERS /I norm )(N ulk /N surf ) where I SERS is the

the ulk smple, N ulk is the numer of the nlyte molecules under lser illumintion in the ulk smple nd N surf

c 35 µm 3 µm 2 µm d Cu wire e f g Rmn h lser PVP-R6G film 6 9 12 15 18 Rmn shift (cm -1 ) Figure S14.

shows mgnified view of the sme. (d-g) Schemtic illustrting the Pick nd Proe method for R6G detection.

11 11 Enhncement fctor is clculted y using eqution (1) EF=(I SERS /I norm )(N ulk /N surf ) where I SERS is the mesured SERS intensity for the nlyte molecules, I norm is the mesured intensity of norml Rmn scttering from the ulk smple, N ulk is the numer of the nlyte molecules under lser illumintion in the ulk smple nd N surf is the numer of the molecules proed on the µ-cpb. c 35 µm 3 µm 2 µm d Cu wire e f g Rmn h lser PVP-R6G film Rmn shift (cm -1 ) Figure S14. Opticl imge showing () Cu wire pproching the CPB prticle (shown y rrow), () µ- CPB held y the Cu-wire nd (c) shows mgnified view of the sme. (d-g) Schemtic illustrting the Pick nd Proe method for R6G detection. (h) Rmn spectrum otined from the tip of the µ-cpb. In order to study the efficiency of the tip of µ-cpbs pick nd proe method hs performed. This experiment involved the following steps.

12 12 Prepring R6G-PVP lend A.5 wt% of PVP ws dissolved in 1mM R6G/ethnol solution. PVP-R6G film mde on spin coting the solution on cover slip t 2 RPM for 8 min. Fixing µ-cpbs to Cu wire Cu wire ws etched with 2.5 M FeCl 3 until tip of the Cu wire ecme ~1 µm. Cu wire ttched to micromnipultor ws rought ner to the µ-cpb nd 1V is ws pplied etween Si sustrte nd Cu wire for 1 ms. A µ-cpb prticle ws thus gently stuck to Cu wire (dimeter = ~3 µm) nd ws rought over the PVP-R6G film. Pick the PVP-R6G film nd proe through Rmn spectroscopy A zigzg line ws mde y µ-cpb stuck to Cu wire on PVP-R6G film. The height profile showed tht the width of the trench ws ~8 nm nd depth is ~2 nm. The proe molecules (R6G) were chemisored onto the tip of the -CPB y leving the -CPB prticle in contct with the film for 1 hour, Rmn performed on the tip of the µ-cpb. Bsed on the tip rdius, the numer of dsored R6G molecules on the µ-cpb tip estimted. All the peks in the spectrum corresponded to R6G. The ove experiment illustrtes tht even ~ 27 molecules re sufficient for giving SERS. This pick-nd-proe technique for ringing molecules onto the -CPB SERS sustrte ensures the mount of smple required for SERS is miniml, which is very crucil in the cse of iomolecules.

13 Asornce (.u) Trnsverse 68 longitudinl Wvelength (nm) Figure S15. Vis-NIR sorption spectrum of µ-cpbs References 1 Jn, N. R., Gerhert, L., Ore, S. O. & Murphy, C. J. Anisotropic Chemicl Rectivity of Gold Spheroids nd Nnorods. Lngmuir 18, (22). 2 Liu & Guyot-Sionnest, P. Mechnism of Silver(I)-Assisted Growth of Gold Nnorods nd Bipyrmids. J. Phys. Chem. B 19, (25). 3 Zhng, X. et l. Synthesis nd Growth Mechnism of Pentgonl Bipyrmid-Shped Gold-Rich Au/Ag Alloy Nnoprticles. Lngmuir 23, (27). 4 Kou, X. et l. Growth of Gold Bipyrmids with Improved Yield nd Their Curvture-Directed Oxidtion. Smll 3, (27). 5 Pelton, M. et l. Dmping of coustic virtions in gold nnoprticles. Nt. Nnotechnol. 4, (29). 6 Zhng, S. et l. Nnonecklces ssemled from gold rods, spheres, nd ipyrmids. Chem. Commun (27). 7 Wu, H.-L., Chen, C.-H. & Hung, M. H. Seed-Medited Synthesis of Brnched Gold Nnocrystls Derived from the Side Growth of Pentgonl Bipyrmids nd the Formtion of Gold Nnostrs. Chem. Mter 21, (28). 8 Burgin, J., Liu, M. & Guyot-Sionnest, P. Dielectric Sensing with Deposited Gold Bipyrmids. J. Phys. Chem. C 112, (28). 9 Ling, H., Yng, H., Wng, W., Li, J. & Xu, H. High-Yield Uniform Synthesis nd Microstructure-Determintion of Rice-Shped Silver Nnocrystls. J. Am. Chem. Soc 131, (29). 1 Chen, H. M., Liu, R.-S. & Tsi, D. P. A Verstile Route to the Controlled Synthesis of Gold Nnostructures. Cryst. Growth Des. 9, (29). 11 Lee, S., Myer, K. M. & Hfner, J. H. Improved Loclized Surfce Plsmon Resonnce Immunossy with Gold Bipyrmid Sustrtes. Anl. Chem. 81, (29). 12 Myer, K. M., Ho, F., Lee, S., Nordlnder, P. & Hfner, J. H. A single molecule immunossy y loclized surfce plsmon resonnce. Nnotechnology 21, (21).

14 14 13 Senpti, D., Singh, A. K. & Ry, P. C. Rel time monitoring of the shpe evolution of rnched gold nnostructure. Chem. Phys. Lett. 487, (21). 14 Zheng, Y. et l. Fcile Synthesis of Gold Nnorice Enclosed y High-Index Fcets nd Its Appliction for CO Oxidtion. Smll 7, (211). 15 Wng, H., Brndl, D. W., Le, F., Nordlnder, P. & Hls, N. J. Nnorice: A Hyrid Plsmonic Nnostructure. Nno Lett. 6, (26). 16 Shen, H.-xi., Yo, J.-lin. & Gu, R.-o. Friction nd chrcteristics of spindle Fe 2 O core/shell prticles. Trns. Nonferrous Met. Soc. Chin 19, (29). 17 Trn, T. T. & Lu, X. Synergistic Effect of Ag nd Pd Ions on Shpe-Selective Growth of Polyhedrl Au Nnocrystls with High-Index Fcets. J. Phys. Chem. C 115, (211). 18 Cro-Argiy, E., Rodriguez-Gonzlez, B., Pstoriz-Sntos, I., Perez-Juste, J. & Liz-Mrzn, L. M. Growth of penttwinned gold nnorods into truncted dechedr. Nnoscle 2, (21). 19 Chen, H. et l. Shpe-Dependent Refrctive Index Sensitivities of Gold Nnocrystls with the Sme Plsmon Resonnce Wvelength. J. Phys. Chem. C 113, (29). 2 Alonso, G., Berhult, G. & Chinelli, R. R. Synthesis nd chrcteriztion of tetrlkylmmonium thiomolydtes nd thiotungsttes in queous solution. Inorgnic Chimic Act 316, (21). 21 Tin, N., Zhou, Z.-Y. & Sun, S.-G. Pltinum Metl Ctlysts of High-Index Surfces: From Single-Crystl Plnes to Electrochemiclly Shpe-Controlled Nnoprticles. J. Phys. Chem. C 112, (28).

Silicon Nanowire Based Single-Molecule SERS Sensor

Silicon Nanowire Based Single-Molecule SERS Sensor Supporting informtion Silicon Nnowire Bsed Single-Molecule SERS Sensor Hui Wng, Xuemei Hn, Xuemei Ou, Chun-Sing Lee, Xiohong Zhng* nd Shuit-Tong Lee S1, A series of Si nnowires coted with compct ggregtes