Preparation, optical properties and cell staining of water soluble amine-terminated PAMAM G2.0-Au nanocomposites

Abstract

The solution chemical and optical characteristics of formation of amine-terminated polyamidoamine dendrimer G2.0(NH₂-PAMAM G2.0)-Au nanocomposites in the aqueous solution of NH₂-PAMAM G2.0 at various mole ratios of Au(III) to NH₂-PAMAM G2.0 were studied by both UV-visible spectrometry and fluorospectrometry. The NH₂-PAMAM G2.0-Au nanocomposites, with a type of structure in which one Au nanoparticle is surrounded by several NH₂-PAMAM G2.0 dendrimers, emit strong bluish violet fluorescence, and are uniform, water soluble and biocompatible as well as very stable in frozen conditions. The size of gold nanoparticles in the nanocomposites is about 2.5 nm and decreases with the increase of NH₂-PAMAM G2.0 concentration. The NH₂-PAMAM G2. 0 plays an important role in acting as host or micro-reactor for Au(III) before Au(III) reduction and acting as dispersant and stabilizer for gold nanoparticles after Au(III) reduction. Preliminary experiments of cells staining to human embryonic lung fibroblast cell lines show that the NH₂-PAMAM G2.0-Au nanocomposites can be used as optical imaging markers for bioanalyses and medical diagnoses.

Keywords

polyamidoamine dendrimer / nanocomposites / gold nanoparticles / optical properties / cell staining

References

[1] AlivisatosA P. Semiconductor clusters, nanocyrstals, and quantum dots [J]. Science, 1996, 271: 933-937

[2] WarrenC W C, NieS M. Quantum dot bioconjugates for ultrasensitive nonisotopic detection [J]. Science, 1998, 281: 2016-2018

[3] TatonT A, MirkinC A, LetsingerR L. Scanometric DNA array detection with nanoparticle probes [J]. Science, 2000, 289: 1757-1760

[4] SandhuK K, McintoshC M, SimardJ M, et al.. Gold nanoparticles mediated transfection of mammalian cells [J]. Bioconjug Chem, 2002, 13(1): 3-6

[5] JinRong-chao, WuGuo-sheng, LiZhi, et al.. What controls the melting properties of DNA-Linked gold nanoparticle assemblies? [J]. J Am Chem Soc, 2003, 125(6): 1643-1654

[6] Liz-MarzanL M, GiersigM, MulvaneyP. Synthesis of nanosized gold-silica core-shell particles[J]. Langmuir, 1996, 12(18): 4329-4335

[7] EsumiK, TakeiN, YoshimuraT. Antioxidant-potentiality of gold-chitosan nanocomposites [J]. Colloids Surf B, 2003, 32(2): 117-123

[8] ShankarS S, RaiA, AhmadA, et al.. Rapid synthesis of Au, Ag, and bimetallic Au core Ag shell nanoparticles using Neem (Azadirachta indica) leaf broth[J]. J Colloid Interface Sci, 2004, 275(2): 496-502

[9] RobertsJ C, BhalgatM K, ZeraR T. Preliminary biological evaluation of polyamidoamine (PAMAM) Starburst™ dendrimers [J]. J Biomed Mater Res, 1996, 30(1): 53-65

[10] TorigoeK, SuzukiA, EsumiK. Au (III)-PAMAM interaction and formation of Au-PAMAM nanocomposites in ethyl acetate[J]. J Colloid Interface Sci, 2001, 241(2): 346-356

[11] BaloghL, ValluzziR, LaverdureK S, et al.. Formation of silver and gold dendrimer nanocomposites[J]. J Nanoparticle Res, 1999, 1(3): 353-368

[12] ZhaoM, SunL, CrooksR M. Preparation of Cu nanoclusters within dendrimer templates[J]. J Am Chem Soc, 1998, 120(19): 4877-4878

[13] EsumiK, IsonoR, YoshimuraT. Preparation of PAMAM- and PPI-Metal (silver, platinum and palladium) nanocomposites and their catalytic activities for reduction of 4-nitrophenol[J]. Langmuir, 2004, 20(1): 237-243

[14] EsumiK, KameoA, SuzukiA, et al.. Preparation of gold nanoparticles in formamide and N, N-dimethyl-formamide in the presence of poly(amidoamine) dendrimers with surface methyl ester groups[J]. Colloids Surfaces A, 2001, 189(1–3): 155-161

[15] EsumilK, HosoyaT, SuzukiA, et al.. Preparation of hydrophobically modified poly (amidoamine) dendrimer-encapsulated gold nanoparticles in organic solvents[J]. J Colloid Interface Sci, 2000, 229(1): 303-306

[16] EsumiK, MiyamotoK, YoshimuraT. Comparison of PAMAM-Au and PPI-Au nanocomposites and their catalytic activity for reduction of 4-nitrophenol[J]. J Colloid Interface Sci, 2002, 254(2): 402-405

[17] ZhengJ, PettyJ T, DicksonR M. High quantum yield blue emission from water-soluble Au₈ nanodots [J]. J Am Chem Soc, 2003, 125(26): 7780-7781

[18] TomaliaD A, BakerH, DewldJ, et al.. A new class of polymers: starbuest-dendritic macromolecules[J]. Polymer J, 1985, 17(1): 117-132

[19] ShenLi, HuNai-fei. Heme Protein films with polyamidoamine dendrimer: direct electrochemistry and electrocatalysis [J]. Biochim Biophys Acta, 2004, 1608(1): 23-33

[20] EsumiK, SuzukiA, YamahiraA, et al.. Role of poly-(amidoamine) dendrimers for preparing nanoparticles of gold, platinum and silver [J]. Langmuir, 2000, 16(6): 2604-2608

[21] HuangT, MurrayR W. Quenching of [Ru(bpy)₃]²⁺ fluorescence by binding to Au nanoparticles[J]. Langmuir, 2002, 18(18): 7077-7081

[22] JiangZhi-liang, FengZhong-wei, LiYan-sheng, et al.. Resonance scattering spectroscopic study of gold nanoparticle[J]. Sci China B, 2001, 31(2): 183-188(in Chinese)

[23] WestR, WangY, GoodsonT. Nonlinear absorption properties in novel gold nanostructured topologies [J]. J Phys Chem B, 2003, 107(15): 3419-3426

[24] KimY G, OhS K, CrooksR M. Preparation and characterization of 1–2 nm dendrimer-encapsulated gold nanoparticles having very narrow size distributions[J]. Chem Mater, 2004, 16(1): 167-172

[25] GrohnF, BauerB J, AkpaluY A, et al.. Dendrimer templates for the formation of gold nanoclusters[J]. Macromolecules, 2000, 33(16): 6042-6050