Loading Of Gold Nanoparticles Research Articles

Determination of the Minimum Temperature Required for Selective Photothermal Destruction of Cancer Cells with the Use of Immunotargeted Gold Nanoparticles

Laser photothermal therapy of cancer with the use of gold nanoparticles immunotargeted to molecular markers on the cell surface has been shown to be an effective modality to selectively kill cancer cells at much lower laser powers than those needed for healthy cells. To elucidate the minimum light dosimetry required to induce cell death, photothermal destruction of two cancerous cell lines and a noncancerous cell line treated with antiepidermal growth factor receptor (anti-EGFR) antibody-conjugated gold nanoparticles is studied, and a numerical heat transport model is used to estimate the local temperature rise within the cells as a result of the laser heating of the gold nanoparticles. It is found that cell samples with higher nanoparticle loading require a lower incident laser power to achieve a certain temperature rise. Numerically estimated temperatures of 70-80 degrees C achieved by heating the gold particles agree well with the measured threshold temperature for destruction of the cell lines by oven heating and those measured in an earlier nanoshell method. Specific binding of anti-EGFR antibody to cancerous cells overexpressing EGFR selectively increases the gold nanoparticle loading within cancerous cells, thus allowing the cancerous cells to be destroyed at lower laser power thresholds than needed for the noncancerous cells. In addition, photothermal therapy using gold nanoparticles requires lower laser power thresholds than therapies using conventional dyes due to the much higher absorption coefficient of the gold nanoparticles.

Synthesis of hierarchically porous inorganic–metal site-isolated nanocomposites

Hierarchically porous inorganic nanocomposites have been synthesized combining interconnected macropores and mesopores with a high loading of site-isolated gold nanoparticles.

Extended-range glucose biosensor via layer-by-layer assembly incorporating gold nanoparticles

We report on a glucose oxidase (GOx)/polyelectrolyte (PE)/gold nanoparticle (AuNP) multilayer films that can be utilized as efficient glucose biosensors by layer-by-layer self-assembly method. Electrochemical impedance spectroscopy (EIS) and UV-visible spectroscopy were adopted to monitor the regular growth of the multilayer films. The role of gold nanoparticles integrated in the multilayer films not only increase the amount and activity of GOx, but also significantly improve the electron-transfer characteristics of the films. The performance of the multilayer films for sensing glucose could be tailored by controlling the gold nanoparticles loading in the film and the number of layers. A biosensor constructed by four poly(dimethyldiallylammonium chloride) (PDDA)/AuNP/PDDA/GOx multilayer films exhibited a wide linear calibration range from 0 to 60.0 mM with the detection limit of 3.0 microM for the detection of glucose. The dynamic range can be extended up to 120 mM. The biosensor has good stability and reproducibility.

Nanostructured Electrochemical Sensor Based on Dense Gold Nanoparticle Films

Polyelectrolyte (PE)/gold nanoparticle hybrid films that can be utilized as efficient electrochemical sensors were prepared by infiltrating 4-(dimethylamino)pyridine-stabilized gold nanoparticles (DMAP−AuNP) into PE multilayers preassembled on indium tin oxide (ITO) electrodes. Quartz crystal microgravimetry (QCM) and UV−vis spectroscopy showed that via this infiltration method, composite films with densely packed DMAP−AuNP were obtained. Electrochemical experiments revealed that the presence of gold nanoparticles in the PE multilayers could significantly improve the electron-transfer characteristics of the films, which showed high electrocatalytic activity to the oxidation of nitric oxide (NO). The sensitivity of the composite films for measuring NO could be further tailored by controlling the gold nanoparticle loading in the film.