Near-perfect fidelity polarization-encoded multilayer optical data storage based on aligned gold nanorods

Encoding information in light polarization is of great importance in facilitating optical data storage(ODS)for information security and data storage capacity escalation.However,despite recent advances in nanophotonic techniques vastly en-hancing the feasibility of applying polarization channels,the data fidelity in reconstructed bits has been constrained by severe crosstalks occurring between varied polarization angles during data recording and reading process,which gravely hindered the utilization of this technique in practice.In this paper,we demonstrate an ultra-low crosstalk polarization-en-coding multilayer ODS technique for high-fidelity data recording and retrieving by utilizing a nanofibre-based nanocom-posite film involving highly aligned gold nanorods(GNRs).With parallelizing the gold nanorods in the recording medium,the information carrier configuration minimizes miswriting and misreading possibilities for information input and output,respectively,compared with its randomly self-assembled counterparts.The enhanced data accuracy has significantly im-proved the bit recall fidelity that is quantified by a correlation coefficient higher than 0.99.It is anticipated that the demon-strated technique can facilitate the development of multiplexing ODS for a greener future.

Surface-enhanced Raman scattering properties of highly ordered self-assemblies of gold nanorods with different aspect ratios

Gold nanorods with aspect ratios of from 1 （particles） to 31.6 were synthesized by the seed-mediated method and packed in a highly ordered structure on a large scale on silicon substrates through capillary force induced self-assembly behaviour during solvent evaporation. The gold nanorod surface exhibits a strong enhancing effect on Raman scattering spectroscopy. The enhancement of Raman scattering for two model molecules （2-naphthalenethiol and rhodamine 6C） is about 5-6 orders of magnitude. By changing the aspect ratio of the Au nanorods, we found that the enhancement factors decreased with the increase of aspect ratios. The observed Raman scattering enhancement is strong and should be ascribed to the surface plasmon coupling between closely packed nanorods, which may result in huge local electromagnetic field enhancements in those confined junctions.

Efficient plasmon-enhanced perovskite solar cells by molecularly isolated gold nanorods

Perovskite solar cells(PSCs)are becoming a promising candidate for next-generation photovoltaic cells due to their attractive power conversion efficiency(PCE).Plasmonic enhancement is regarded as an optical tuning approach for further improving the PCE of single-junction PSCs toward Shockley-Queisser limit.Herein,we introduce molecularly isolated gold nanorods(Au NRs),bearing relatively stronger scattering ability and localized surface plasmonic resonance(LSPR)effect,in the rear side of perovskites in PSCs,for promoting light harvesting and for electrical enhancement.Owing to the larger refractive index and better matched energy level alignment,the 4-mercaptobenzoic acid molecules coated on Au NRs prove to play important dual roles:isolating the metallic Au NRs from contacting with perovskite,and facilitating more efficient charge separation and transport across the interface under the synergetic LSPR effect of Au NRs.Our work highlights the capability of the plasmonic approach by nanorods and by molecular isolation,extending nanoparticle-based plasmonic approaches,toward highly efficient plasmon-enhanced PSCs.

High Thermal Stability Gold Nanorods Included Alumina Film Prepared by a Dip-lifting Method

Here,we designed and prepared a new nano-assembly structure of gold nanorods dispersion medium to improve the data storage life.The surface of gold nanorods was wrapped with a layer of silica shell to enhance the nanorod thermal stability,and then injected into the porous alumina to form a nano-assembly structured film.The experimental results show that gold nanorods are uniformly dispersed in the alumina film,and the optical properties of gold nanorods will not change after heat treatment below 200℃.It is expected that this film can be used for five-dimensional data storage and greatly improve the thermal stability of stored data.

Preparation of Gold Nanorods of High Quality and High Aspect Ratio

We report the synthesis of gold nanorods （NRs） by seed-mediated growth method. A small amount of different shapes such as triangles, hexagons and a large amount of rods are obtained by varying the proportion of seed to metal salt, adding NaOH to growth solution as well as using the seed solution of CTAB-capped agent. The gold nanorod （NR） formation yield is improved. Meanwhile, the growth mechanism of high yield gold NRs is discussed. The high quality single size NRs can be separated from polydisperse samples using surfactant-assisted nanorod self-assembly. The gold NRs synthesized were characterized by transmission electron microscopy （TEM） and UV-vis spectroscopy.

Gold nanorods for gambogicacid intracellular delivery

OBJECTIVE To improve the anticancer drug gambogic acid’s effect by using titanium dioxide coated gold nanorods(GNR/Ti O2)as a drug carrier.METHODS Biocompatibility and cellular uptake of GNR/Ti O2was studied in human glioblastoma U-87 MG cells.Cel viability was evaluated by ATP assay and calcein AM staining.Lyso SensorTMGreen DND-189 and Hoechst 33342 were used to analyze the intracellular location of GNR/Ti O2.The in vitro anticancer effect of gambogic acid loaded nanoparticles was compared with free drug.RESULTS The results showed that GNR/Ti O2is biocompatible,andthey are localized at the intracellular acidic compartments of endosomes and lysosomes.The intracellular drug content delivered via GNR/Ti O2was 6 fold higher than the free form,thus dramatically enhancing the anticancer effect of gambogic acid.Furthermore,mild photothermal therapy also showed synergistic effect with the drug.CONCLUSION Our study suggested that GNR/Ti O2is a promising anticancer drug carrier。

Gold Nanorods-mediated Photothermal Therapy Guided by Vascular Interventional Radiation to Inhibit Cancer Metastasis

The purpose of this study was to investigate the inhibitory effect of gold nanorods-mediated photothermal therapy on liver metastasis of colorectal cancer under the guidance of vascular interventional radiology.A total of 80 patients admitted to our hospital from February 2018 to February 2020 were selected and randomly divided into study group and control group with 40 cases each,among which the control group received 125I seed implantation combined with chemotherapy.On this basis,the study group were added the gold nanorods(AuNRs)to the photothermal therapy additionally.The clinical efficacy,postoperative complications and postoperative survival rates of the two groups were compared.The results showed that the total clinical effective rate was 82.5%in the study group,which was significantly better than 67.5%in the control group,and the difference was statistically significant(P<0.05).In addition,the incidence of leukocytosis,nausea,vomiting and delayed diarrhea in the study group was significantly lower than that in the control group,with statistically significant differences(P<0.05).There were no statistically significant differences in the proportion of elevated body temperature,liver dysfunction,or moderate liver pain between the two groups(P>0.05).Therefore,under the guidance of vascular interventional radiology,Au NRs are safe and effective materials for the treatment of liver metastasis of colorectal cancer,which can reduce complications and improve postoperative survival rates.

Hyaluronic Acid-RGD Peptide Conjugated Mesoporous Silica-coated Gold Nanorods for Cancer Dual-targeted Chemo-photothermal Therapy

A multifunctional drug delivery system（GNRs@mSiO_2-HA-RGD） was developed by conjugating targeting ligand hyaluronic acid（HA） and RGD with mesoporous silica-coated gold nanorods（GNRs@mSiO_2） for dual-targeted chemo-photothermal therapy. The physiochemical properties of the prepared nanoparticles were characterized by FTIR, UV-vis spectra, and ~1H NMR. Doxorubicin hydrochloride（DOX）, an anticancer drug, was used as the model drug to investigate the drug loading, in vitro drug release profiles and cytotoxicity. The experimental results show that DOX-GNRs@mSiO_2-HA-RGD is synthesized with a mean diameter of 116 nm and a sufficient load capacity of about 19.8%. It also has p H-enzyme sensitive and NIRtriggered drug release manner. Cellular uptake indicates that DOX-GNRs@mSiO_2-HA-RGD exhibits a higher cellular uptake via CD44 receptor and integrin receptor mediated endocytosis compared with the GNRs@mSiO_2 modified with one receptor or no receptor. In comparison with chemotherapy or photothermal therapy alone, DOX-GNRs@mSiO_2-HA-RGD displayes the synergistic effects and achieves a higher therapeutic efficacy. It can be expected that DOX-GNRs@mSiO_2-HA-RGD is a potential dual-targeted chemo-photothermal therapeutic platform for effective cancer treatment.

Detection of Adhesion Molecules on Inflamed Macrophages at Early-Stage Using SERS Probe Gold Nanorods

In recent years, it has been shown that inflammatory biomarkers can be used as an effective signal for disease diagnoses. The early detection of these signals provides useful information that could prevent the occurrence of severe diseases. Here, we employed surface-enhanced Raman scattering(SERS) probe gold nanorods(GNRs) as a tool for the early detection of inflammatory molecules in inflamed cells. A murine macrophage cell line(Raw264.7) stimulated with lipopolysaccharide(LPS) was used as a model in this study. The prepared SERS probe GNRs containing 4-mercaptobenzoic acid as a Raman reporter to generate SERS signals were used for detection of intracellular adhesion molecule-1(ICAM-1) in macrophages after treatment with LPS for varying lengths of time. Our results show that SERS probe GNRs could detect significant differences in the expression of ICAM-1 molecules in LPS-treated macrophages compared to those in untreated macrophages after only 1 h of LPS treatment. In contrast, when using fluorescent labeling or enzyme-linked immunosorbent assays(ELISA) to detect ICAM-1, significant differences between inflamed and un-inflamed macrophages were not seen until the cells had been treated with LPS for 5 h. These results indicate that our SERS probe GNRs provide a higher sensitivity for detecting biomarker molecules in inflamed macrophages than the conventional fluorescence and ELISA techniques, and could therefore be useful as a potential diagnostic tool for managing disease risk.

Amperometric glucose biosensor based on gold nanorods and chitosan comodified Au electrode

Au nanorods were prepared by a seeding growth approach and used in fabricating the nanorod-enhancing glucose biosensor. The high affinity of chitosan for Au nanorods associated with its amino groups resulted in the formation of a layer of Au nanorods on the surface of Au electrode. It served as an intermediator to retain high efficient and stable immobilization of the enzyme. The performance of biosensors was investigated by cyclic voltammetry （CV）, in the presence of artificial redox mediator, ferrocenecarboxaldehyde. The biosensor had a fast response to glucose, and the response time was less than 10 s. The results indicated that the gold nanorods could enhance the current response to glucose. The detection limits of glucose can reach 10 mM, and the Michaelis-Menten constant Km^app is 13.62 mM.

Seedless Synthesis of Gold Nanorods with 5–10 nm in Diameters:a Comprehensive Study

Small gold nanorods(AuNRs),namely AuNRs with less than 10 nm in diameter,possess a high absorption-to-scattering ratio,a large surface area-to-volume ratio,as well as high cellular uptake behaviors.In this study,we systematically investigate seedless synthesis of AuNRs with diameters ranging from 5 nm to 10 nm.It has been found that several experimental conditions,including the chain length of the used cationic surfactants,and the concentrations of ascorbic acid,NaBH4,and AgNO_(3)can profoundly affect the obtained products.Under optimal conditions,the production yields of the obtained several AuNRs with different diameters can exceed 90%and even reach almost 100%.The conversion of gold precursors to AuNRs was estimated to be 70%–77%as measured by absorption spectroscopy and inductively coupled plasma mass spectrometry.

Engineering miniature gold nanorods with tailorable plasmonic wavelength in NIR region via ternary surfactants mediated growth

Plasmonic nanoparticles are endowed profound capability for sensing,biomedicine,and cancer therapy.However,the inaccessibly adjustable wavelength in near infrared(NIR)region window and size limit for the particles penetration in tumor strongly hinder their developments.Miniature gold nanorods(mini-Au NRs)with diameter less than 12 nm can effectively address this challenge due to the tiny size and tailorable NIR absorption.Herein,we adopt ternary surfactants(hexadecyl trimethyl ammonium bromide(CTAB),sodium oleate(NaOL),and sodium salicylate(NaSal))mediated growth strategy to precisely synthesize miniature Au NRs under micelle space-confinement.Importantly,the selectively dense accumulation of ternary surfactants can efficiently improve the micellar stacking parameters(p)and lower micellar free energy(F),further tends to achieve the formation of Au NRs with tiny diameter and high purity.Compared with that of conventional methods,the purity of mini-Au NRs up to 100%can be dramatically improved via varying the relative concentration of ternary surfactants.The diameter of Au NRs can be dynamically controlled to 6,8,and 11 nm through regulating the concentration of silver nitrate and the mole ratio of ternary surfactants.Such ternary surfactants system is favorable for the aging of tiny Au NRs,and further enables the aspect ratio-tunable in the region from 2.70 to 7.32,as well as tailorable plasmonic wavelength in wide NIR window from 700 to 1,147 nm.Therefore,our findings shed a light on the precise preparation of small sized plasmonic nanoparticles and pave the way to applications in biomedicine,imaging,and cancer therapy.

Temperature-modulated inversion and switching of chiroptical responses in dynamic side-by-side oligomers of gold nanorods

Herein,a new strategy is proposed for achieving dynamic chiral controls in self-assembly systems of plasmonic nanorods based on temperature-modulation.Via enlarging Au{100}side facets of Au nanorod(AuNR)building block and changing surface ligand from often-used cetyltrimethylammonium bromide(CTAB)to cetylpyridinium chloride(CPC),inversion of chiroptical signal in side-by-side(SS)oligomers is realized.Under the guide of chiral cysteine(Cys),Au{100}side facet-linked SS rods twist in the opposite direction compared with Au{110}side facet-linked counterparts.At high CPC concentration,by controlling the incubation temperature of chiral Cys,the dominant twist mode can be regulated.Finite-difference time-domain(FDTD)simulations indicate the key role of the twisting dihedral angle of the oligomers in driving chiral signal inversion.At low CPC concentration,a temperature-sensitive chiral switching is observed owing to the conformation change of the CPC ligand layer.The temperature-modulated chiral responses are based on the interactions of chiral molecules,achiral surface ligands,and exposed facets of the building block.The rich dynamic tunability of chiroptical responses of plasmonic assemblies may find applications in stimulus-responsive nanodevices.

Gold nanorods together with HSP inhibitor-VER-155008 micelles for colon cancer mild-temperature photothermal therapy

Enhancing the heat-sensitivity of tumor cells provides an alternative solution to maintaining the therapeutic outcome of photothermal therapy(PTT). In this study, we constructed a therapeutic system, which was composed of methoxy-polyethylene-glycol-coated-gold-nanorods(MPEG-AuN R) and VER-155008-micelles, to evaluate the effect of VER-155008 on the sensitivity of tumor cells to heat, and further investigate the therapeutic outcome of MPEG-AuN R mediated PTT combined with VER-155008-micelles. VER-155008-micelles downregulate the expression of heat shock proteins and attenuate the heat-resistance of tumor cell. The survival of HCT116 cells treated with VER-155008-micelles under 45 ℃ is equal to that treated with high temperature hyperthermia(55 ℃) in vitro. Furthermore, we proved either the MPEG-AuN R or VER-155008-micelles can be accumulate in the tumor site by photoacoustic imaging and fluorescent imaging. In vivo anti-cancer evaluation showed that tumor size remarkably decreased(smaller than 100 mm^3 or vanished) when treated with combing 45℃ mild PTT system, which contrasted to the tumor size when treated with individual 45℃ mild PTT(around 500nm^3) or normal saline as control(larger than 2000 nm^3). These results proved that the VER-155008-micelles can attenuate the heat-resistance of tumor cells and enhance the therapeutic outcome of mild-temperature photothermal therapy.

Biomimetic albumin-modified gold nanorods for photothermo-chemotherapy and macrophage polarization modulation

Nanotechnology-based photothermal therapy has attracted great attention in the past decade. Nevertheless, photothermal therapy has some inherent drawbacks, such as the uneven heat production and limited laser penetration, often leading to insufficient treatment outcomes. Here, we developed a combination strategy to improve cancer therapy. The biomimetic albumin-modified gold nanorods(AuNRs) were prepared with incorporation of paclitaxel(PTX). This therapeutic system was characterized by several features. First, the albumin modification enhanced the biocompatibility and colloidal stability. Second, the surface-coated albumin promoted cellular uptake via the albumin-binding protein pathway. Third, PTX was incorporated via hydrophobic interaction between PTX and the albumin lipophilic domain. Fourth, the system can be used for combined photothermo-chemotherapy for yielding synergistic effects. The antitumor activity of the system was evaluated both in vitro and in vivo using the HCT116 colon cancer cell and tumor model. The combination therapy was found with an enhanced treatment efficiency and no obvious side effect. Most importantly, the thermal effect was also discovered with the ability to modulate the tumor microenvironments and suppress the macrophages polarization towards the M2 pro-tumor phenotype. It could be a mechanism for photothermal immunotherapy. The combination strategy and the system provide a potential method for cancer therapy.

Doxorubicin-conjugated pH-responsive gold nanorods for combined photothermal therapy and chemotherapy of cancer

Cancer chemotherapy can be hindered by drug resistance which leads to lower drug efficiency.Here,we have developed a drug delivery system that tethers doxorubicin to the surface of gold nanorods via a pHsensitive linkage(AuNRs@DOX),for a combined photothermal and chemical therapy for cancer.First,AuNRs@DOX is ingested by HepG2 liver cancer cells.After endocytosis,the acidic pH triggers the release of doxorubicin,which leads to chemotherapeutic effects.The gold nanorods are not only carriers of DOX,but also photothermal conversion agents.In the presence of an 808 nm near-infrared laser,AuNRs@DOX significantly enhance the cytotoxicity of doxorubicin via the photothermal effect,which induces elevated apoptosis of hepG2 cancer cells,leading to better therapeutic effects in vitro and in vivo.

Gold nanorods-mediated efficient synergistic immunotherapy for detection and inhibition of postoperative tumor recurrence

Tumor recurrence after surgery is the main cause of treatment failure.However,the initial stage of recurrence is not easy to detect,and it is difficult to cure in the late stage.In order to improve the life quality of postoperative patients,an efficient synergistic immunotherapy was developed to achieve early diagnosis and treatment of post-surgical tumor recurrence,simultaneously.In this paper,two kinds of theranostic agents based on gold nanorods(AuNRs)platform were prepared.AuNRs and quantum dots(QDs)in one agent was used for the detection of carcinoembryonic antigen(CEA),using fluorescence resonance energy transfer(FRET)technology to indicate the occurrence of in situ recurrence,while AuNRs in the other agent was used for photothermal therapy(PTT),together with antiPDL1 mediated immunotherapy to alleviate the process of tumor metastasis.A series of assays indicated that this synergistic immunotherapy could induce tumor cell death and the increased generation of CD3;/CD4;T-lymphocytes and CD3+;CD8;T-lymphocytes.Besides,more immune factors(IL-2,IL-6,and IFN-γ)produced by synergistic immunotherapy were secreted than mono-immunotherapy.This cooperative immunotherapy strategy could be utilized for diagnosis and treatment of postoperative tumor recurrence at the same time,providing a new perspective for basic and clinical research.

Gold nanorods and nanohydroxyapatite hybrid hydrogel for preventing bone tumor recurrence via postoperative photothermal therapy and bone regeneration promotion

Osteosarcoma is a malignant bone tumor,which often occurs in adolescents.However,surgical resection usually fails to completely remove the tumor clinically,which has been the main cause of postoperative recurrence and metastasis,resulting in the high death rate of patients.At the same time,osteosarcoma invades a large area of the bone defect,which cannot be self-repaired and seriously affects the life quality of the patients.Herein,a bifunctional methacrylated gelatin/methacrylated chondroitin sulfate hydrogel hybrid gold nanorods(GNRs)and nanohydroxyapatite(nHA),which possessed excellent photothermal effect,was constructed to eradicate residual tumor after surgery and bone regeneration.In vitro,K7M2wt cells(a mouse bone tumor cell line)can be efficiently eradicated by photothermal therapy of the hybrid hydrogel.Meanwhile,the hydrogel mimics the extracellular matrix to promote proliferation and osteogenic differentiation of mesenchymal stem cells.The GNRs/nHA hybrid hydrogel was capable of photothermal treatment of postoperative tumors and bone defect repair in a mice model of tibia osteosarcoma.Therefore,the hybrid hydrogel possesses dual functions of tumor therapy and bone regeneration,which shows great potential in curing bone tumors and provides a new hope for tumor-related bone complex disease.

pH-mediated synthesis of monodisperse gold nanorods with quantitative yield and molecular level insight

Although gold nanorods(GNRs)have been produced with different dimensions and aspect ratios,the current synthesis methods through seed-mediated growth are far from ideal,for instance,the quality(rod yield)and the quantity(gold conversion)cannot be simultaneously satisfied.More critically,there is no molecular level understanding of the growth mechanism.Here,we solved the problem by employing the stoichiometric ratio of reactants and tuning the reactivity of the reductant through adjusting the initial pH value of the growth solution to achieve both good quality and high quantity simultaneously.We also extended our strategy to other enols besides ascorbic acid,such as phenolic compounds,and found that the optimal pH for GNRs synthesis depends on the structure of the individual compound.The mechanistic insight greatly enriches the toolbox of reductants for GNRs growth and makes it possible to synthesize GNRs at both acidic and basic conditions.An interesting phenomenon is that for most of the phenolic compounds we tested,the morphology of the final products follows the same sphere-rod-sphere trend as the initial pH value of the reaction increases,whether it is under acidic or basic conditions,which cannot be explained by any previously proposed mechanism.The effect of pH is mainly attributed to the regulation of the reduction potential of the reductants,and thus the reaction rate.A model has been proposed to explain the dependence of anisotropic growth of GNRs on the concentration gradient of reactants around the seeds,which is decided by both the reaction rate and diffusion rate.

Matryoshka-caged gold nanorods： Synthesis, plasmonic properties, and catalytic activity

Matryoshka-caged gold nanorods （mCGNRs） were successfully synthesized by alternating between a seed-mediated silver-coating method and galvanic replacement reactions （GRRs）. As the number of matryoshka layers of the mCGNRs increased, the plasmon resonance peak broadened and was red-shifted, and the catalytic activity towards the reduction of 4-nitrophenol （4-NTP） increased. When mCGNRs with 6 layers were used as nanocatalysts in the reduction of 4-nitrophenol, the reaction rate coefficient was 5.2- and 3.7-times higher than that of the gold-nanorod- and caged-gold-nanorod-catalyzed reductions of 4-nitrophenol, respectively. In addition, the surface-plasmon-resonance-based absorption of light enhanced the catalytic performance of the mCGNRs. With the support of a polyurethane foam, the mCGNRs synthesized in this study can be applied as recydable heterogeneous catalysts for the reduction of 4-nitrophenol.