Photothermal Effect Of Gold Nanoparticles Research Articles

Physical Unclonable Functions Based on Photothermal Effect of Gold Nanoparticles.

Physical unclonable functions (PUFs) based on uncontrollable fabrication randomness are promising candidates for anticounterfeiting applications. Currently, the most popular optical PUFs are generally constructed from the scattering, fluorescent, or Raman phenomenon of nanomaterials. To further improve the security level of optical PUFs, advanced functions transparent to the above optical phenomenon have always been perused by researchers. Herein, we propose a new type of PUF based on the photothermal effect of gold nanoparticles, which shows negligible scattering, fluorescent, or Raman responses. The gold nanoparticles are randomly dispersed onto the surface of fused silica, which can enhance the photothermal effect and facilitate high contrast responses. By tuning the areal density of the gold nanoparticles, the optimized encoding capacity (2319) and the total authentication error probability (3.6428 × 10-24) are achieved from our PUF due to excellent bit uniformity (0.519) and inter Hamming distances (0.503). Moreover, the intra-Hamming distance (0.044) indicates the desired reliability. This advanced PUF with invisible features and high contrast responses provides a promising opportunity to implement authentication and identification with high security.

Photothermal Effect of Gold Nanoparticles as a Nanomedicine for Diagnosis and Therapeutics.

Gold nanoparticles (AuNPs) have received great attention for various medical applications due to their unique physicochemical properties. AuNPs with tunable optical properties in the visible and near-infrared regions have been utilized in a variety of applications such as in vitro diagnostics, in vivo imaging, and therapeutics. Among the applications, this review will pay more attention to recent developments in diagnostic and therapeutic applications based on the photothermal (PT) effect of AuNPs. In particular, the PT effect of AuNPs has played an important role in medical applications utilizing light, such as photoacoustic imaging, photon polymerase chain reaction (PCR), and hyperthermia therapy. First, we discuss the fundamentals of the optical properties in detail to understand the background of the PT effect of AuNPs. For diagnostic applications, the ability of AuNPs to efficiently convert absorbed light energy into heat to generate enhanced acoustic waves can lead to significant enhancements in photoacoustic signal intensity. Integration of the PT effect of AuNPs with PCR may open new opportunities for technological innovation called photonic PCR, where light is used to enable fast and accurate temperature cycling for DNA amplification. Additionally, beyond the existing thermotherapy of AuNPs, the PT effect of AuNPs can be further applied to cancer immunotherapy. Controlled PT damage to cancer cells triggers an immune response, which is useful for obtaining better outcomes in combination with immune checkpoint inhibitors or vaccines. Therefore, this review examines applications to nanomedicine based on the PT effect among the unique optical properties of AuNPs, understands the basic principles, the advantages and disadvantages of each technology, and understands the importance of a multidisciplinary approach. Based on this, it is expected that it will help understand the current status and development direction of new nanoparticle-based disease diagnosis methods and treatment methods, and we hope that it will inspire the development of new innovative technologies.

The photothermal effect of gold nanoparticles prepared by electrochemical method at different voltages

This paper was performed to evaluate the photothermal effect of pure gold nanoparticles (AuNPs) prepared by electrochemical method at different voltages, under laser irradiation in the safe wavelength range. The formation, morphological, and structural properties of AuNPs were analyzed by UV-vis absorption spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The stability and dispersion of AuNPs were investigated by dynamic light scattering (DLS) and Zeta potential measurements. The photothermal effect was evaluated by the temperature change of the sample under the green laser irradiated at a wavelength of 532 nm. The results showed the formation of the AuNPs has a spherical shape and high purity; the particle size distribution is in the range of 10 - 40 nm depending on the synthesis voltage, and the absorption peak is in the range of 530 to 556 nm. The temperature of the AuNPs solution increased by 1.3 to 6 oC, compared to that of bi-distilled water under the same conditions of laser irradiation. This paper shows the photothermal effect of AuNPs prepared by the electrochemical method at different voltages, it changed markedly when irradiated with a green laser in the safe wavelength range.

Hydration of Arylacetylenes Promoted by the Photothermal ­Effect of Gold Nanoparticles

AbstractWith the help of the photothermal effect of gold nanoparticles (AuNPs), the hydration of the arylacetylenes to synthesize carbonyl compounds is successfully achieved. The reaction proceeds smoothly for various substrates and the ketone products are obtained in good isolated yields up to 91%. The successful gram-scale and sunlight-exposure experiments illustrate the potential application of this method in the future organic syntheses.

Novel Development of Nanoparticles-A Promising Direction for Precise Tumor Management.

Although the clinical application of nanoparticles is still limited by biological barriers and distribution, with the deepening of our understanding of nanoparticles over the past decades, people are gradually breaking through the previous limitations in the diagnosis and treatment of tumors, providing novel strategies for clinical decision makers. The transition of nanoparticles from passive targeting to active tumor-targeting by abundant surface-modified nanoparticles is also a development process of precision cancer treatment. Different particles can be used as targeted delivery tools of antitumor drugs. The mechanism of gold nanoparticles inducing apoptosis and cycle arrest of tumor cells has been discovered. Moreover, the unique photothermal effect of gold nanoparticles may be widely used in tumor therapy in the future, with less side effects on surrounding tissues. Lipid-based nanoparticles are expected to overcome the blood-brain barrier due to their special characteristics, while polymer-based nanoparticles show better biocompatibility and lower toxicity. In this paper, we discuss the development of nanoparticles in tumor therapy and the challenges that need to be addressed.

Large Terahertz Phase Shift Induced by Photothermal Effect of Gold Nanoparticles Incorporated with Toluene

AbstractPhase and amplitude modulation of propagating terahertz (THz) waves in free space is essential for many rapidly developing THz technologies. Herein, an all‐optical, high‐performance, and ultra‐broadband THz phase shifter is demonstrated. Tunable phase shift is achieved by the photothermal effect of plasmonic gold nanoparticles in toluene, which can induce variations in the THz refractive index of toluene as the temperature increases. A phase shift of 270° at 1 THz can be achieved under a laser irradiation of 2.5 W (3.9 W cm−2) on the mixture solution. Constructive and destructive interference of THz waves can be achieved by tuning the relative phase of two split THz waves, which can be controlled by the power of the irradiation laser. This is the first broadband THz phase modulator in free space driven by optical stimuli, and it provides a new solution for tuning the phase shift of THz waves.

Drug Release System Controlled by Photothermal Effect of Gold Nanoparticles

Controlled drug release in response to light irradiation is an important technique for focusing drug elution to specific sites and reducing the side effects of drugs in normal tissue. In one example, we used double-stranded DNA to modify gold nanorods. When the gold nanorods were heated by irradiation with near-infrared light, single-stranded DNA was released. Thus, we successfully prepared a controlled release system that responds to near-infrared irradiation by combining heat-labile linkers such as double-stranded DNA. However, the drug-loading capacity on the surface of the nanoparticles was limited. To improve the loading efficiency, we encapsulated gold nanorods in poly(lactic-co-glycolic acid) (PLGA) nanoparticles, where PLGA acted as a drug payload. When the gold nanorod-containing PLGA nanoparticles were irradiated with a near-infrared laser, the PLGA nanoparticles were destroyed and significant drug release was observed. In another example, silver nanoplates were used as a near-infrared responsive photothermal nanodevice. Silver nanoparticles show antimicrobial activity that we expected could be controlled by light irradiation. First, we coated the silver nanoplates with gold atoms to mask the antimicrobial activity. When the gold-coated silver nanoplates were irradiated with a near-infrared pulsed laser, the shape of the silver nanoplates changed from plate-like to spherical, and silver ions were released. As a result, the antibacterial activity of the silver nanoplates was recovered. In this review, we outline examples of controlled release systems that respond to light irradiation. We believe that this review will contribute to improving the efficiency and safety of chemotherapy.

Visible Light Responsive DNA Thermotropic Liquid Crystals Based on a Photothermal Effect of Gold Nanoparticles

Visible Light Responsive DNA Thermotropic Liquid Crystals Based on a Photothermal Effect of Gold Nanoparticles

Photothermal release of an encapsulated therapeutic agent from polymer-wrapped gold nanoparticles.

Visible light is used to generate heat from gold nanoparticles wrapped in an amphiphilic polymer shell and trigger a reverse Diels–Alder reaction of a ‘caged’ tyrphostin therapeutic agent. The hydrophilic nature of the released agent results in it travelling from the polymer to the bulk medium, while the byproduct of the reaction is trapped in the hydrophobic layer of the nano-assembly.

Sensitive biosensor for p53 DNA sequence based on the photothermal effect of gold nanoparticles and the signal amplification of locked nucleic acid functionalized DNA walkers using a thermometer as readout

A convenient photothermal biosensor was constructed for p53 DNA sequence detection based on the high discrimination capability of locked nucleic acid and high efficiency of signal amplification strategy of DNA walkers and difference photothermal effect between aggregated and dispersed gold nanoparticles (AuNPs). The presence of target activated the DNA walkers via the high affinity between target and complementary locked nucleic acid in the probe strand, resulting in the hybridization of the walker strand and substrate strand to form a specific enzyme recognition site. Under the cleavage of the endonuclease, single-stranded DNA (ssDNA) was released to the solution. Then the walker strand bound to a new substrate strand, and the next round of cleavage was triggered. The released ssDNA enhanced the stability of AuNPs against salt-induced aggregation. Given difference photothermal effects of the aggregated AuNPs and dispersed AuNPs under the near-infrared laser, the change of the temperature was detected by a common thermometer easily, which had a linear relationship with the target concentration in the range of 2.0–120.0 pM, the detection limit was 1.4 pM (S/N = 3). The proposed photothermal assay has been applied to detect p53 DNA sequence spiked complex samples with satisfying results.

Dual Pathway for Promotion of Stem Cell Neural Differentiation Mediated by Gold Nanocomposites.

The neural differentiation of embryonic stem cells (ESCs) is of great value in the treatment of neurodegenerative diseases. On the basis of the two related signaling pathways that direct the neural differentiation of ESCs, we used gold nanoparticles (GNP) as a means of combining chemical and physical cues to trigger the neurogenic differentiation of stem cells. Neural differentiation-related functional units (glyco and sulfonate units on glycosaminoglycans, GAG) were anchored on the GNP surface and were then transferred to the cell membrane surface via GNP-membrane interactions. The functional units were able to activate the GAG-related signaling pathway, in turn promoting differentiation and maturation of stem cells into neuronal lineages. In addition, using the photothermal effect of GNP, the differentiation-inducing factor retinoic acid (RA), could be actively delivered into cells via laser irradiation. The RA-related intracellular signaling pathway was thereby further triggered, resulting in strong promotion of neurogenesis with a 300-fold increase in mature neural marker expression. The gold nanocomposites developed in this work provide the basis for a new strategy directing ESCs differentiation into nerve cells with high efficiency and high purity by acting on two related signaling pathways.

An immunofiltration strip method based on the photothermal effect of gold nanoparticles for the detection of Escherichia coli O157:H7.

An immunofiltration strip is a promising rapid and powerful tool for the routine monitoring of foodborne pathogenic bacteria. However, the strip assay is generally less sensitive than other immunological techniques. A novel immunofiltration strip method based on the photothermal effect of gold nanoparticles (GNPs) was developed for the sensitive, rapid, simple handheld and low-cost detection of Escherichia coli O157:H7. The photothermal effect of GNPs was used to achieve the amplification of signals to improve the sensitivity of the strip method. The thermal contrasts caused by the photothermal effect were proportional to the bacteria concentrations and yield an almost logarithmic relation. Under optimal conditions, the detection limit was 1.95 × 104 CFU mL-1, and the sensitivity was improved about ten times compared to that of the conventional visual strip method. In brief, the photothermal based immunofiltration strip could be used for the rapid and sensitive detection of other pathogens as a great potential food quality control technique.

N-Thiocarbazole-based gold nanoparticles: synthesis, characterization and anti-proliferative activity evaluation

Carbazoles are aromatic heterocyclic compounds derived from the fusion of a benzene ring with an indole nucleus in 2,3 position. Today, many carbazole derivatives are widely studied as anticancer, anti-fungal, antioxidants, photoconductor, anti-bacterial, antimalarials, anti-Alzheimer, anti-tuberculosis, anti-HIV agents and for the treatment of obesity. Some of them, differently substituted on carbazole nucleus, have been synthetized and their biological activity have been evaluated. The purpose of this work is the study of new species obtained binding, a series of carbazole derivatives in which the carbazolic nitrogen has been functionalized with different alkyl-thiol chains, with gold nanoparticles, synthesized in organic solvent. The formation of self-assembled monolayers of these ligands is obtained on the spherical surface of gold nanoparticles, with a stabilizing effect against aggregation. These systems might present a double innovative function, matching an antineoplastic activity typical of carbazoles, with the photothermal effects of gold nanoparticles.

Rapid detection method and portable device based on the photothermal effect of gold nanoparticles

Gold nanoparticle (GNP)-labeled immunochromatography test strip (ICTS) has been widely used in different fields, but its sensitivity still require further improvement. In this work, a rapid and quantitative test strip detection method based on the photothermal effect of GNPs was established using a temperature sensor. A portable sensor device was fabricated based on the above method, and the main operating parameters were optimized. Three types of analyte models (cells, macromolecules, and small molecules) were chosen to evaluate the application of the sensor device using the commercial ICTS. The detection limit is at least 1 order of magnitude lower than that of the traditional visual detection ICTS. The other strip type of dot immunogold filtration test was adopted to further improve the sensitivity. The sensitivity of the sensor detection method was similar to that of the infrared camera method, and the proposed sensor device has obvious advantage of low-cost, as well as the usage of a small portable instrument, ease of use and rapid test. The portable sensor device based on the photothermal effect of GNPs can be used as a new and promising device for simple, quantitative, rapid, and on-site screening of analyte by ICTS.

Light-induced microfluidic chip based on shape memory gold nanoparticles/poly (vinyl alcohol) nanocomposites

A shape memory light-induced microfluidic technology is applied in preprogrammed microfluidic chip based on shape memory gold nanoparticles/poly (vinyl alcohol) nanocomposites. The shape memory gold nanoparticles/poly (vinyl alcohol) nanocomposites display excellent light-induced shape memory property with recovery ratio of nearly 100% in visible light. The crosslinked network of light-induced shape memory gold nanoparticles/poly (vinyl alcohol) nanocomposites forms by aldol reaction, esterification, and/or hydrogen bonding of poly (vinyl alcohol), glutaraldehyde, and gold nanoparticles. The light-induced shape memory mechanism of shape memory gold nanoparticles/poly (vinyl alcohol) nanocomposites is based on photothermal effect of gold nanoparticles and shape memory effect of poly (vinyl alcohol)-based shape memory polymer (SMP). In this report, a light-induced microfluidic microvalve is demonstrated based on the shape memory gold nanoparticles/poly (vinyl alcohol) nanocomposites. This research presents demonstration of the shape memory light-induced intelligent microfluidic chip. The light-induced SMP microfluidic microvalve would yield practical, physical, and technological advantages for disposable integrated microfluidic chip laboratories.

Continuous adsorption and photothermal lysis of airborne bacteria using a gold-nanoparticle-embedded-geometrically activated surface interaction (gold-GASI) chip.

The rapid increase in the concentration of pathogenic airborne bacteria is a serious issue because of their infectivity. Due to the abundance of these infectious pathogens in the environment, researchers have developed devices to detect airborne pathogens using microfluidic technologies. Such devices represent a significant improvement over conventional techniques that rely on colony counting or biochemical assays, which are time as well as labor consuming. In addition to these detection methods, researchers have also shown that the photothermal effects of gold nanoparticles can be used to kill pathogenic bacteria. Thus, in this study, we combined a microfluidic device with a photothermal system to capture, lyse, and detect airborne bacteria. Specifically, we synthesized gold nanoparticles in poly(dimethylsiloxane) (PDMS) microfluidic chips to enrich and extract DNA from the pathogenic bacteria in air samples. The geometrically activated surface interaction (GASI) chip was employed, which was previously designed by our group and basically modified herringbone structure, to capture bacteria and increase the frequency of bacterial contact with the gold-nanoparticle-embedded PDMS. We design a microfluidic herringbone chip to capture bacteria and increase the frequency of bacterial contact with the gold-nanoparticle-embedded PDMS. Finally, the bacteria-captured PDMS microchips are irradiated at 532nm using a 300-mW laser for 10min, and the destruction of bacteria is verified by fluorescence microscopy and scanning electron microscopy (SEM).

On-demand curing of polydimethylsiloxane (PDMS) using the photothermal effect of gold nanoparticles.

The photothermal effect of gold nanoparticles (AuNPs) produces extremely localized heat that can be harnessed to drive large scale chemical reactions by simultaneously generating many individual reactions on the nanoscale. We use the photothermal effect to enhance the curing rate of polydimethylsiloxane (PDMS) by a factor of 4.9 × 109. Photothermal curing occurs via crosslinking reactions between vinyl and Si-H groups of the pre-polymer, and the course of the reaction was followed by monitoring the disappearance of infrared bands associated with these functional groups. Using mass spectroscopy, we verify that the major polymer m/z peaks are identical for both traditionally and photothermally cured polymers, indicating that the photothermal effect of AuNPs is an effective way in which to supply on-demand curing of PDMS.

Photothermally induced scratch healing effects of thermoplastic nanocomposites with gold nanoparticles

A novel method for providing thermoplastic coatings with light-triggered self-healing ability is reported. Normal thermoplastic coatings can be healed efficiently via local heating generated by photothermal effect of gold nanoparticles (Au NPs). Small amounts of Au NPs were successfully dispersed into the coatings. Once the scratch occurred in the coating surface, a laser could be used to illuminate Au NPs to generate a large amount of heat which dramatically increased the local temperature through the photothermal effect. It would melt the polymer and form local deformation to merge the scratch efficiently. It had been confirmed that the coating containing Au NPs had the healing ability. After healing, the surface morphology and the mechanical property were recovered. The mechanism of the healing was also investigated and it was found that the Au NPs content and irradiation intensity played the key roles in the healing process. Through adjusting these two elements, the maximum temperature rise could achieve 225.5 °C. Healing tests were carried out on multiple types of thermoplastic coatings (PAA, PVAc, PS and TPU) and repeated healing was also achieved.

Photothermal effects of gold nanoparticles induced by light emitting diodes

Gold nanoparticles (AuNPs) have a great potential for biomedical application due to the superior photothermal efficiency. The photothermal effects of AuNPs in different heated media under a polychromatic and three monochromatic light emitting diode (LED) illuminations were experimentally investigated to explore the possible use of LED for the thermotherapy treatment. The results show that the noticeable temperature increase of the heated media can be achieved by the injection of AuNPs induced by LED illumination. The selection of the LED wavelength depends not only on the absorption peak wavelengths of the AuNP with different sizes but also on the absorption coefficient of the heated media. Either a smaller AuNP size, higher AuNP concentration, or higher power density can lead to a higher temperature increase. The AuNP aggregation occurred in the heated egg white, agar solution, and blood leads to the lower temperature increase comparing with the heated water. Moreover, the LED light with a wavelength of 635 nm results in better heating for the heated blood and biological tissue in vitro comparing with other selected wavelengths due to the lower light absorption of the blood, deeper penetration in biological tissues, and the light absorption rate of AuNP to a certain degree.

Gold Nanoparticle Patterning on Planar Type MEA for Selective Inhibition of Cultured Neuronal Network Using NIR Photothermal Effect

Event Abstract Back to Event Gold Nanoparticle Patterning on Planar Type MEA for Selective Inhibition of Cultured Neuronal Network Using NIR Photothermal Effect Gu-Haeng Lee1* and Yoonkey Nam2 1 Korea Advanced Institute of Science and Technology, Dept. of Bio and Brain Engineering, Korea 2 Korea Advanced Institute of Science and Technology, Dept. of Bio and Brain Engineering, Korea 1. Motivation MEA (multi-electrodes array) is a powerful tool to research about dissociated neuronal culture activities. There are several methods to control neuronal networks like electrical stimulation, drug stimulation and cell patterning. Especially, limited methods are used to inhibit neurons using drug or optogenetic method. Inhibition method using the photothermal effect of gold nanoparticles is recently shown [1]. In this work, we tried to combine photothermal inhibition and patterning method for selective inhibition that is hard to achieve using conventional electrical stimulation. 2. Material and Methods GNR (gold nanorod) was PEGylated by SH-PEG-NH2(+) to stabilize and modify the surface property. Substrates were planar type MEAs.with the surface of silicon nitride or ONO(Oxide/Nitride/Oxide). After one minute of air plasma treatment on substrates, GNR solution was loaded on the substrate for 12~24 hours. Then, substrates were rinsed with distilled water and dried by an airgun. A PDMS stamp was treated with air plasma for one minute and it was brought in contact with the GNR coated substrates for one minute. After peeling off stamp carefully, we can see the lift-up result. 3. Results Figure1(left). SEM image of the lift-up result on the cover glass. GNRs remain on the bright part. Size of single dot is 3 ¥ìm Figure 2(right). Modified phase contrast image of MEA with GNR(dark) pattern. Distance between center of electrodes is 200 ¥ìm For the lift-up result, the removal ratio of GNR on the substrate was changed to the different condition, like property of GNR, GNR loading time, time after GNR coating, plasma treatment time on PDMS. We saw consistent results from a cover glass substrate that was not necessary to align pattern. There were no limits of pattern shape similar to micro contact printing and achieve circle shape 3-¥ìm size pattern to smallest pattern. We performed lift-up from two kinds of surface condition and GNR charge property. 4. Discussion Lift-up soft lithography can be used in a large area, so it is good for controlling large size network. Cell patterning using micro contact printing or micro-molding in the capillary can be added, because GNR patterning does not affect to network morphology. 5. Conclusion We show GNR micro patterning using lift-up soft lithography was operating well on MEA surface. We may selectively inhibit cultured neuronal network by GNR patterning which is relatively easy compared to light patterning or optogenetic methods. We expect this work helps research about neuronal network by controlling network activities.