scholarly journals Distinct Detection of Ganoderma Boninense On Metal Oxides-Gold Nanoparticle Composite Deposited Interdigitated Electrode DNA sensor

2021 ◽  
Vol 2129 (1) ◽  
pp. 012050
Author(s):  
V Thivina ◽  
U Hashim ◽  
S C B Gopinath ◽  
A Ayoib ◽  
N K S Nordin ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Metal Oxides ◽  
Volume Ratio ◽  
Diagnostic Tools ◽  
Dna Sensor ◽  
Ganoderma Boninense ◽  
Interdigitated Electrode ◽  
Basal Stem Rot ◽  
Lift Off ◽  
Oil Palm Industry

Abstract Oil palms suffer severe losses due to Ganoderma boninense infection that causes Basal Stem Rot (BSR). The available detection measuring the severity of BSR disease have not proved satisfactory output. Due to the influence of oil palm industry in country’s economy, effective and efficient means of diagnostic measure is mandatory. Among the available diagnostic tools, biosensors were redeemed to yield the most rapid and selective results. To overcome the current issues, herein Interdigitated Electrode (IDE) electrochemical DNA biosensor to detect Ganoderma boninense was successfully designed and fabricated by thermal deposition. Lift-off photolithography fabrication process was applied followed by the surface chemical functionalization via seed deposition. Zinc Oxide (ZnO) and Titanium Dioxide (TiO2) were overlaid and the functionalized metal oxides IDE surfaces were used to detect DNA sequence complementation from Ganoderma boninense. Furthermore, gold nanoparticles were doped to increase the surface to volume ratio and enhance biocompatibility. Characterizations were made by validating the sensor’s topology characteristics and electrical characteristics. From the results recorded, it has been justified that IDE with ZnO doped with gold nanoparticles surface serves as an excellent DNA sensor for the detection of Ganoderma boninense with a remarkable current of 290 nA and 176 nA for immobilization and hybridization respectively.

scholarly journals Three-dimensional platinum nanoparticle-based bridges for ammonia gas sensing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nishchay A. Isaac ◽  
Johannes Reiprich ◽  
Leslie Schlag ◽  
Pedro H. O. Moreira ◽  
Mostafa Baloochi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Response Times ◽  
High Surface ◽  
Three Dimensional ◽  
Performance Testing ◽  
Volume Ratio ◽  
Platinum Nanoparticle ◽  
Ammonia Gas ◽  
Lift Off

AbstractThis study demonstrates the fabrication of self-aligning three-dimensional (3D) platinum bridges for ammonia gas sensing using gas-phase electrodeposition. This deposition scheme can guide charged nanoparticles to predetermined locations on a surface with sub-micrometer resolution. A shutter-free deposition is possible, preventing the use of additional steps for lift-off and improving material yield. This method uses a spark discharge-based platinum nanoparticle source in combination with sequentially biased surface electrodes and charged photoresist patterns on a glass substrate. In this way, the parallel growth of multiple sensing nodes, in this case 3D self-aligning nanoparticle-based bridges, is accomplished. An array containing 360 locally grown bridges made out of 5 nm platinum nanoparticles is fabricated. The high surface-to-volume ratio of the 3D bridge morphology enables fast response and room temperature operated sensing capabilities. The bridges are preconditioned for ~ 24 h in nitrogen gas before being used for performance testing, ensuring drift-free sensor performance. In this study, platinum bridges are demonstrated to detect ammonia (NH3) with concentrations between 1400 and 100 ppm. The sensing mechanism, response times, cross-sensitivity, selectivity, and sensor stability are discussed. The device showed a sensor response of ~ 4% at 100 ppm NH3 with a 70% response time of 8 min at room temperature.

scholarly journals First Record of Basal Stem Rot of Foxtail Palm Wodyetia bifurcata Caused by Ganoderma boninense in Malaysia

Plant Disease ◽  
2018 ◽  
Vol 102 (7) ◽  
pp. 1461-1461 ◽  
Author(s):  
A. Mohd Farid ◽  
W. A. Wan Muhd Azrul ◽  
S. A. Syazwan ◽  
S. Y. Lee ◽  
R. Mohamed
Keyword(s):  
First Record ◽  
Stem Rot ◽  
Ganoderma Boninense ◽  
Basal Stem Rot

Smart Theranostic Applications of Metal Nanoparticles Against Cancer

2021 ◽  
pp. 319-336
Author(s):  
Malathi Balasubramaniyan ◽  
Abdul Azeez Nazeer ◽  
Vimalraj Vinayagam ◽  
Sudarshana Deepa Vijaykumar
Keyword(s):  
Metal Nanoparticles ◽  
Complex Disease ◽  
Volume Ratio ◽  
Biological Properties ◽  
Diagnostic Tools ◽  
Theranostic Agent ◽  
Ancient Times ◽  
Theranostic Applications ◽  
Synthesis Methodology ◽  
Enhanced Surface

Metals such as silver, gold, and copper were used in ancient times for their medicinal properties. When these metals are converted to nanoparticles, they show unique and advanced physicochemical and biological properties due to their enhanced surface to volume ratio. Hence, these properties are utilized by researchers to develop highly specific diagnostic tools as well as a therapeutic agent against cancer. Cancer is a complex disease-causing desolation and death. Early detection and treatment is the only way to evade mortality. This chapter focuses on metal nanoparticles used as a theranostic agent against cancer. It summarizes the synthesis methodology along with their advantages, drawbacks and characterizations. Their recent application in diagnosing and treating cancer has also been highlighted.

Catalytic Performance of SO2 by Colloidal Gold Supported on Nano γ-Fe2O3

2010 ◽  
Vol 178 ◽  
pp. 65-70 ◽  
Author(s):  
Sheng Rui Xu ◽  
Qin Shuai ◽  
Jin Hua Cheng ◽  
Xiao Ge Wang
Keyword(s):  
Gas Chromatography ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Metal Oxides ◽  
Water Vapour ◽  
Colloidal Gold ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Sulfate Species

A new catalyst of gold supported on nanometal oxide for oxidation of SO2 was developed. Deposition-precipitation method was used to prepare gold-based catalysts. The catalytic activity of the catalysts was evaluated by determining the concentration of SO2 with gas chromatography under reaction temperature from 100 to 700°C. The results showed that there was an enhancement of catalytic activity when gold nanoparticles were dispersed on the surface of nano-metal oxides, furthermore, γ-Fe2O3 showed the highest activity as the support of the colloidal gold supported catalysts among the nanometal oxides including γ-Fe2O3, Fe2O3, ZnO, and Al2O3. It was also found that water vapour in the reaction enhanced the catalytic activity of Au/γ-Fe2O3. The Au/γ-Fe2O3 was characterized by XRD and FTIR methods, which indicated that the gold nanoparticles were dispersed on the γ-Fe2O3 support and sulfate species were formed on the surface of catalysts.

Tailoring nano-catalysts: turning gold nanoparticles on bulk metal oxides to inverse nano-metal oxides on large gold particles

2015 ◽  
Vol 51 (27) ◽  
pp. 5975-5978 ◽  
Author(s):  
Guofeng Zhao ◽  
Xin-Ping Wu ◽  
Ruijuan Chai ◽  
Qiaofei Zhang ◽  
Xue-Qing Gong ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Metal Oxides ◽  
High Activity ◽  
Gas Phase ◽  
Gold Particle ◽  
Alcohol Oxidation ◽  
Bulk Metal ◽  
Gold Particles ◽  
Nano Oxide ◽  
Nano Catalysts

Inverse nano-oxide/large-gold-particle catalysts create an anti-sintering structure with a large interface thereby showing high activity/selectivity for the gas-phase alcohol oxidation with dramatic stability improvement.

scholarly journals Continuous tuning of the plasmon resonance frequency of porous gold nanoparticles by mixed oxide layers

2020 ◽  
Vol 27 (6) ◽  
pp. 1583-1588
Author(s):  
Laura Juhász ◽  
Bence Parditka ◽  
Péter Petrik ◽  
Csaba Cserháti ◽  
Zoltán Erdélyi
Keyword(s):  
Gold Nanoparticles ◽  
Resonance Frequency ◽  
Mixed Oxide ◽  
High Surface ◽  
Volume Ratio ◽  
Mixture Ratio ◽  
Optical Extinction ◽  
Oxide Layers ◽  
Porous Gold ◽  
Wide Range

Abstract Porous gold nanoparticles (PGNs) are very popular due to their high surface/volume ratio, moreover they have stronger plasmonic properties than their solid counterparts. These properties make the porous gold nanoparticles very useful for lots of applications, for instance chemical sensors, cancer therapy applications. For applications, however, it is indispensable that the resonance frequency (RF) of a plasmonic structure to be tuneable. In this work we show that the RF can be set in a wide range as desired by coating the PGNs by mixed oxide layers. By changing the composition of the coating layer, that is the mixture ratio, the RF can be shifted practically continuously in a wide range determined by the refractive index of the used oxides. As a demonstration, PGNs were coated with mixed alumina-titania oxide layers (5–7 nm) using plasma-enhanced atomic layer deposition method. The oxide layer, beside as a tuning tool, also stabilises the structure of the PGNs when are exposed to elevated temperature. This is shown by the influence of the temperature (from $$350\, ^{\circ }\hbox {C}$$ 350 ∘ C up to $$900\, ^{\circ }\hbox {C}$$ 900 ∘ C ) on the morphology, and as a consequence the optical extinction spectra, of the oxide coated PGNs.

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