- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
PEGylated hollow gold nanoparticles for combined X-ray radiation and photothermal therapy in vitro and enhanced CT imaging in vivo
摘要： Up until now, hollow gold nanoparticles (HGNPs) with a spherical cavity have garnered much interest as theranostic agents in cancer therapy due to their high X-ray absorption and photothermal conversion ability. Herein, we describe the design of PEGylated hollow gold nanoparticles (mPEG@HGNPs) for combined X-ray radiation and photothermal therapy in vitro and enhanced computed tomography (CT) imaging in vivo using a breast tumor model. In vitro results revealed that mPEG@HGNPs could achieve a synergistic antitumor effect when irradiated by combined X-ray radiation and 808 nm near infrared laser light. Furthermore, mPEG@HGNPs exhibited a favorable tumor targeting effect and good CT contrast enhancement in both xenografted and orthotopic breast tumor models, due to the stealth effect of PEG which increased the enhanced permeability and retention (EPR) effect. These results suggest that mPEG@HGNPs may serve as multifunctional nanocomposites for cancer combination therapy and, thus, should be further studied.
关键词： hollow gold nanoparticles,CT imaging,PEGylated,combination therapy
更新于2025-09-23 15:23:52
-
Improvement of Cancer Therapy by TAT Peptide Conjugated Gold Nanoparticles
摘要： Gold nanoparticles (AuNPs) are potent anticancer agent that controls drug delivery to tumors. Here, we describe the identification of TAT-Cell Penetrating Peptide (TAT-CPP) conjugated AuNPs, as a novel delivery system to the cancerous regions. TAT-peptide was modified to BSA-AuNPs [Bovine Serum Albumin (BSA) coated AuNPs] electrostatically. The binding efficiency of TAT-AuNPs was tested using Dynamic Light Scattering, UV–Vis spectrophotometer and Zeta potential. The nano-complex (BSA-AuNPs; with and without TAT-CPP) was applied against Rhabdomyosarcoma and Murine fibroblast (L20B) cancer lines, in vitro. Cytotoxicity effect was evaluated by MTT assay at 0.125, 0.25, 0.5 and 1 mg/ml concentration for 24 and 48 h incubation time. Results demonstrated that TAT-(BSA-AuNPs) exhibits significant toxicity for both cancer cell lines. TAT-CPP has improved cancer cell reduction, where cytotoxicity more than 80% has been achieved. This study was conducted to achieve the simplicity and facility in cancer therapy, where the small-sized TAT-AuNPs acts as a simple therapeutic agent in the specific delivery and targeting the deep, irregular, and complicated cancer regions in the human body. Therefore, it could replace other cancer treatment techniques, even dispense the laser irradiation in the phototherml therapy.
关键词： BSA,CPP,Small sized gold nanoparticles,Cancer treatment,TAT
更新于2025-09-23 15:23:52
-
Colorimetric detection of normetanephrine, a pheochromocytoma biomarker, using bifunctionalised gold nanoparticles
摘要： A simple and effective colorimetric method for the detection of normetanephrine (NMN), an O-methylated metabolite of norepinephrine, using functionalised gold nanoparticles is described. This metabolite is an important biomarker in the diagnosis of adrenal tumours such as pheocromocytoma or paraganglioma. The colorimetric probe consists of spherical gold nanoparticles (AuNPs) functionalised with two different ligands, which specifically recognize different functional groups in normetanephrine. Thus, a benzaldehyde-terminated ligand was used for the recognition of the amino alcohol moiety in NMN, by forming the corresponding oxazolidine. On the other hand, N-acetyl-cysteine was chosen for the recognition of the phenolic hydroxyl group through the formation of hydrogen bonds. The selective double molecular recognition between the probe and the hydroxyl and the amino-alcohol moieties of normetanephrine led to interparticle-crosslinking aggregation resulting in a change in the color of the solution, from red to blue, which could be observed by naked eye. The probe was highly selective towards normetanephrine and no color changes were observed in the presence of other neurotransmitter metabolites such as homovanillic acid (HVA) (dopamine metabolite), 5-hydroxyindoleacetic acid (5-HIAA) (serotonin metabolite), or other biomolecules present in urine such as glucose (Glc), uric acid (U.A), and urea. Finally, the probe was evaluated in synthetic urine with constituents that mimic human urine, where a limit of detection of 0.5 mM was achieved.
关键词： Gold nanoparticles,Aggregation,Pheocromocytoma,Normetanephrine,Colorimetric detection
更新于2025-09-23 15:23:52
-
Cholesterol Functionalization of Gold Nanoparticles Enhances Photo-Activation of Neural Activity
摘要： Gold nanoparticles (AuNPs) attached to the extracellular leaflet of the plasma membrane of neurons can enable the generation of action potentials (APs) in response to brief pulses of light. Recently described techniques to stably bind AuNP bioconjugates directly to membrane proteins (ion channels) in neurons enable robust AP generation mediated by the photoexcited conjugate. However, a strategy that binds the AuNP to the plasma membrane in a non-protein-specific manner could represent a simple, single-step means of establishing light-responsiveness in multiple types of excitable neurons contained in the same tissue. Based on the ability of cholesterol to insert into the plasma membrane, here we test whether AuNP functionalization with linear dihydrolipoic acid-poly(ethylene) glycol (DHLA-PEG) chains that are distally terminated with cholesterol (AuNP-PEG-Chol) can enable light-induced AP generation in neurons. Dorsal root ganglion (DRG) neurons of rat were labelled with 20 nm diameter spherical AuNP-PEG-Chol conjugates wherein ~30% of the surface ligands (DHLA-PEG-COOH) were conjugated to PEG-Chol. Voltage recordings under current-clamp conditions showed that DRG neurons labeled in this manner exhibited a capacity for AP generation in response to microsecond and millisecond pulses of 532 nm light, a property attributable to the close tethering of AuNP-PEG-Chol conjugates to the plasma membrane facilitated by the cholesterol moiety. Light-induced AP and subthreshold depolarizing responses of the DRG neurons were similar to those previously described for AuNP conjugates targeted to channel proteins using large, multicomponent immunoconjugates. This likely reflected the AuNP-PEG-Chol’s ability, upon plasmonic light absorption and resultant slight and rapid heating of the plasma membrane, to induce a concomitant transmembrane depolarizing capacitive current. Notably, AuNP-PEG-Chol delivered to DRG neurons by inclusion in the buffer contained in the recording pipette/electrode enabled similar light-responsiveness, consistent with the activity of AuNP-PEG-Chol bound to the inner (cytofacial) leaflet of the plasma membrane. Our results demonstrate the ability of AuNP-PEG-Chol conjugates to confer timely stable and direct responsiveness to light in neurons. Further, this strategy represents a general approach for establishing excitable cell photosensitivity that could be of substantial advantage for exploring a given tissue’s suitability for AuNP-mediated photo-control of neural activity.
关键词： nanoparticle functionalization,cholesterol,action potential,neural photo-activation,optocapacitance,gold nanoparticles,photosensitivity,dorsal root ganglion cell
更新于2025-09-23 15:23:52
-
Novel ELISA based on fluorescent quenching of DNA-stabilized silver nanoclusters for detecting E. coli O157:H7
摘要： Escherichia coli O157:H7 (E. coli O157:H7) is a potential threat to human health; thus, a rapid and sensitive method for detecting it is necessary. We designed a single-stranded DNA that contained an appended block and anchoring block. The appended block acted as a scaffold to prepare fluorescent Ag nanoclusters (AgNCs). The anchoring block contained Poly A, which bound with the surface of gold nanoparticles to quench the fluorescence of AgNCs. An interesting ELISA approach for detecting E. coli O157:H7 was established via fluorescent quenching of DNA-stabilized AgNCs by using a sandwich complex. The changes in fluorescence intensity of AgNCs were used to quantitatively detect E. coli O157:H7. The sensitivity for detecting E. coli O157:H7 reached 1.905 × 10^3 CFU/mL with a good linear range. Compared with conventional ELISA, the sensitivity of this technique increased by 30-fold. Moreover, this method demonstrated specificity and reproducibility and could be used in food samples.
关键词： Fluorescence quenching,Ag nanoclusters,Escherichia coli O157:H7,Gold nanoparticles
更新于2025-09-23 15:23:52
-
Miniaturized electrochemiluminescent biochip prepared on gold nanoparticles-loaded mesoporous silica film for visual detection of hydrogen peroxide released from living cells
摘要： Au nanoparticles (NPs) has been widely used for the detection of intracellular H2O2 to enhance the electron transfer process. But AuNPs are easy to aggregate in the live cells environment. Herein we report a rapid, reliable and low-cost electrochemiluminescent (ECL) biochip integrated by AuNPs-loaded mesoporous silica film (MSF) to detect H2O2 released by macrophage cells. The MSF was employed as a template to load AuNPs within the nanochannels to avoid aggregation. H2O2 could be catalyzed by AuNPs to promote the ECL reaction of luminol molecules in solution. The ECL intensity was significantly enhanced, and the peak potential was negatively shifted by 400 mV due to the excellent electrocatalytic ability of AuNPs. The integrated biochip demonstrated good reproducibility, with a wide linear range of 0.1–200 μM and an LOD of 25.3 nM. The reliability was evaluated by applying for the assessment of antioxidant activity of resveratrol using RAW 264.7 macrophage model. The AuNPs-loaded MSF integrated biochip can be easily adapted to the development of improved devices in biosensing, lab-on-a-chip, and nanofluidic systems.
关键词： Gold nanoparticles,Biochip array,Electrochemiluminescence,Reactive oxygen species,Mesoporous silica
更新于2025-09-23 15:23:52
-
Flexible bipyramid-AuNPs based SERS tape sensing strategy for detecting methyl parathion on vegetable and fruit surface
摘要： In present study, a simple and effective surface enhanced Raman scattering (SERS) tape sensing strategy based on bipyramid gold nanoparticles (BP-AuNPs) was developed for sensitive and selective monitoring of methyl parathion residues on vegetable and fruit surface through a simple sampling-and-detection procedure. BP-AuNPs were synthesized by a seed meditated method and systematically characterized using transmission electron microscope (TEM), UV-vis spectrometer, selected area electron diffraction (SAED) and X-Ray diffraction (XRD). The as-synthesized BP-AuNPs showed excellent Raman enhancement effect because their sharp ends provide high electric field enhancement, as revealed by electrodynamic simulations. Also the localized plasmon resonance of the BP-AuNPs matches well with the NIR (785 nm) laser of portable Raman spectrometer, thus maximizing the Raman signal. Two standard SERS probe molecules Rhodamine 6G (R6G) and crystal violet (CV) were first used to prove the effective SERS detection on the model solid (silicon) surface using the BP-AuNPs based tape sensing strategy. The SERS sensor was then applied to detect methyl parathion on surface of cucumbers, tomatoes and apples. A detection limit of ng/cm2 level was easily achieved. The studies have demonstrated that the BP-AuNPs based SERS tape sensing platform can be potentially used to monitor the trace amount of chemical hazards for food and agricultural safety.
关键词： tape sensor,surface enhanced Raman scattering,methyl parathion,bipyramid gold nanoparticles
更新于2025-09-23 15:23:52
-
Exceptional Two-Photon Absorption in Alkynylruthenium-Gold Nanoparticle Hybrids
摘要： Ruthenium alkynyl “star” complexes with tri(2-thienyl)-, tris(1,2,3-triazolyl)-, or triphenyl-benzene cores stabilize gold nanoparticles (AuNPs). Cyclic voltammetry, transmission electron microscopy, molecular modeling, dynamic light scattering, X-ray photoelectron spectroscopy, and energy-dispersive X-ray spectroscopy studies are consistent with ca. 5 trithienyl- or triazolyl-benzene-cored star complexes decorating the exterior of each AuNP. The ca. 2.5 nm diameter (by TEM) trithienylbenzene-cored gold nanoparticle hybrids are significantly less absorbing than classical Brust nanoparticles stabilized by 1-dodecanethiol; with femtosecond pulsed radiation, they exhibit exceptionally strong saturable absorption and two-photon absorption across the visible range and into the NIR region (3,000,000 GM at 500 nm, 46,000 GM at 750 nm; 1 GM = 10-50 cm4 s photon-1).
关键词： Gold nanoparticles,nonlinear optics,inorganic materials,metal alkynyl complexes,organometallics.
更新于2025-09-23 15:23:52
-
Biosensor for point-of-care analysis of immunoglobulins in urine by metal enhanced fluorescence from gold nanoparticles
摘要： Biosensors are easy-to-use and cost-effective devices that are emerging as an attracting tool not only in settling diagnosis or in disease monitoring, but also in mass screening tests, a timely topic that impacts on daily life of the whole society. Nanotechnologies lend themselves to the development of highly sensitive device whose realization has become a very interdisciplinary topic. Relying on the enhancement of the fluorescence signal detected at the surface of patterned gold nanoparticles, we report the behavior of an analytical device in detecting immunoglobulins in real urine samples that shows a limit of detection of approximately 8 μg/L and a linear range of 10-100 μg/L well below the detection limit of nephelometric method, which is the reference method for this analysis. These performances have been reached thanks to an effective surface functionalization technique and can be improved even more if superhydrophobic features of the substrate we produce will be exploited. Since the analyte recognition is realized by antibodies the specificity is very high and, in fact, no interference has been detected by other compounds also present in the real urine samples. The device has been assessed on serum samples by comparing IgG concentrations values obtained by the biosensor with those provided by a nephelometer. In this step we found that our approach allows the analysis of the whole blood without any pretreatment; moreover, it is inherently extendable to the analysis of most biochemical markers in biological fluids.
关键词： antibody,point-of-care device,nanostructured gold surface,photochemical immobilization technique,gold nanoparticles,metal enhanced fluorescence,biosensors
更新于2025-09-23 15:22:29
-
Enlargement of Gold Nanoparticles for Sensitive Immunochromatographic Diagnostics of Potato Brown Rot
摘要： Lateral ?ow immunoassay (LFIA) is a convenient tool for rapid ?eld-based control of various bacterial targets. However, for many applications, the detection limits obtained by LFIA are not suf?cient. In this paper, we propose enlarging gold nanoparticles’ (GNPs) size to develop a sensitive lateral ?ow immunoassay to detect Ralstonia solanacearum. This bacterium is a quarantine organism that causes potato brown rot. We fabricated lateral ?ow test strips using gold nanoparticles (17.4 ± 1.0 nm) as a label and their conjugates with antibodies speci?c to R. solanacearum. We proposed a signal enhancement in the test strips’ test zone due to the tetrachloroauric (III) anion reduction on the GNP surface, and the increase in size of the gold nanoparticles on the test strips was approximately up to 100 nm, as con?rmed by scanning electron microscopy. Overall, the gold enhancement approach decreased the detection limit of R. solanacearum by 33 times, to as low as 3 × 104 cells·mL–1 in the potato tuber extract. The achieved detection limit allows the diagnosis of latent infection in potato tubers. The developed approach based on gold enhancement does not complicate analyses and requires only 3 min. The developed assay together with the sample preparation and gold enlargement requires 15 min. Thus, the developed approach is promising for the development of lateral ?ow test strips and their subsequent introduction into diagnostic practice.
关键词： gold nanoparticles,immunochromatographic diagnostics,potato brown rot,gold particle growth,increase of sensitivity,lateral ?ow immunoassay,test strips,Ralstonia solanacearum
更新于2025-09-23 15:22:29