scholarly journals Room temperature seed mediated growth of gold nanoparticles: mechanistic investigations and life cycle assesment

2015 ◽  
Vol 2 (5) ◽  
pp. 440-453 ◽  
Author(s):  
Weinan Leng ◽  
Paramjeet Pati ◽  
Peter J. Vikesland
Keyword(s):  
Gold Nanoparticles ◽  
Life Cycle ◽  
Room Temperature ◽  
Gold Salt ◽  
Life Cycle Assesment ◽  
Seed Mediated ◽  
Mechanistic Investigations

In this study, we report the first room temperature seed-mediated synthesis of gold nanoparticles (AuNPs) in the presence of citrate and gold salt.

Seed-mediated synthesis and PEG coating of gold nanoparticles for controlling morphology and sizes

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3353-3360
Author(s):  
Susana Helena Arellano Ramírez ◽  
Perla García Casillas ◽  
Christian Chapa González
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Room Temperature ◽  
Colloidal Stability ◽  
Infrared Spectrometry ◽  
Ammonium Bromide ◽  
Chloroauric Acid ◽  
Vis Spectroscopy ◽  
Seed Mediated ◽  
Peg Coating

AbstractA significant area of research is biomedical applications of nanoparticles which involves efforts to control the physicochemical properties through simple and scalable processes. Gold nanoparticles have received considerable attention due to their unique properties that they exhibit based on their morphology. Gold nanospheres (AuNSs) and nanorods (AuNRs) were prepared with a seed-mediated method followed of polyethylene glycol (PEG)-coating. The seeds were prepared with 0.1 M cetyltrimethyl-ammonium bromide (CTAB), 0.005 M chloroauric acid (HAuCl4), and 0.01 M sodium borohydride (NaBH4) solution. Gold nanoparticles with spherical morphology was achieved by growth by aggregation at room temperature, while to achieve the rod morphology 0.1 M silver nitrate (AgNO3) and 0.1 M ascorbic acid solution were added. The gold nanoparticles obtained by the seed-mediated synthesis have spherical or rod shapes, depending on the experimental conditions, and a uniform particle size. Surface functionalization was developed using polyethylene glycol. Morphology, and size distribution of AuNPs were evaluated by Field Emission Scanning Electron Microscopy. The average size of AuNSs, and AuNRs was 7.85nm and 7.96 x 31.47nm respectively. Fourier transform infrared spectrometry was performed to corroborate the presence of PEG in the AuNPs surface. Additionally, suspensions of AuNSs and AuNRs were evaluated by UV-Vis spectroscopy. Gold nanoparticles were stored for several days at room temperature and it was observed that the colloidal stability increased once gold nanoparticles were coated with PEG due to the shield formed in the surface of the NPs and the increase in size which were 9.65±1.90 nm of diameter for AuNSs and for AuNRs were 29.03±5.88 and 8.39±1.02 nm for length and transverse axis, respectively.

Synthesis of Chitosan-Stabilized Gold Nanorod Using Tripolyphosphate

2013 ◽  
Vol 652-654 ◽  
pp. 250-253
Author(s):  
Hua Nan Guan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Chemical Synthesis ◽  
Gold Nanorods ◽  
Gold Nanorod ◽  
Gold Salt ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Seed Mediated

An improvement in the previously reported seed-mediated chemical synthesis of gold nanorods (GNRs) is reported. Gold nanoparticles were prepared by reducing gold salt with a polysaccharide, chitosan, in the presence of tripolyphosphate (TPP). The obtained gold nanoparticles were characterized with UV-vis spectroscopy and transmission electron microscopy. The study shows that TPP plays an important role in the formation of GNRs.

scholarly journals Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 893
Author(s):  
Olufunto T. Fanoro ◽  
Sundararajan Parani ◽  
Rodney Maluleke ◽  
Thabang C. Lebepe ◽  
Jose R. Varghese ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cell Viability ◽  
Leaf Extract ◽  
Room Temperature ◽  
Klebsiella Oxytoca ◽  
Cost Effective ◽  
Average Diameter ◽  
Antibacterial Activities ◽  
Inhibition Concentration ◽  
First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

scholarly journals A study on biology and larval behaviour of fruit piercing moth of Othreis (Eudocima) materna (L.) (Lepidoptera: Noctuidae) on pomegranate, Punica granatum

2021 ◽  
Vol 13 (1) ◽  
pp. 178-182
Author(s):  
Eknath Shendge ◽  
Bapurao Khaire ◽  
Ramrao Chavan
Keyword(s):  
Life Cycle ◽  
Room Temperature ◽  
Punica Granatum ◽  
Tinospora Cordifolia ◽  
Medium Size ◽  
Present Communication ◽  
Larval Behaviour ◽  
First Instar ◽  
Bright Orange ◽  
Lepidoptera Noctuidae

Among different fruit piercing moths, the genus Othreis are the most harmful, causing widespread damage to pomegranate, citrus and mango fruits causing fruit fall in tropical and subtropical countries. The present communication deals with the study on the biology of  Othreis materna (L) from egg to adult’s death which was carried out  at room temperature of the laboratory  to investigate the delicate and vulnerable stages of its life cycle. The life cycle of the moth was completed within 45-61 days, with an average 55.03 days in case of male and within 47-63 days with an average 57.07±4.92 in case of female. Eggs hatching started at night or early in the morning and duration of hatching was 2.72 days. The eggs measured were about 0.95 to 0.03 mm in diameter. The freshly emerged first instar larvae were light yellowish coloured and translucent. The first instar larvae were very active after hatching and they moved 4 to 6 feet for searching the food. The larvae were fed with the leaves of Tinospora cordifolia (Giloy or Guduchi). The total larval duration in days from first, second, third, fourth and fifth instar varied from 2.12±0.01, 1.81±0.05, 2.87±0.02, 3.90±0.11, 4.74±0.38 in days respectively and total larval period was 15.44±0.57. Pupae were dark brown in colour and total pupation period was of 13.81±0.12 days and total adult duration for male and female was 23.08±0.70 and 25.20±0.66 days respectively. The adult of O. materna was bright orange in colour and of medium size. The male was small than the female. This is first study of this type from Marathwada, which will help to trace the vulnerable and delicate stage of the life cycle of this O. materna.

scholarly journals A STUDY OF THE LIFE HISTORY OF TRICHOBILHARZIA CAMERONI SP. NOV. (FAMILY SCHISTOSOMATIDAE)

1953 ◽  
Vol 31 (4) ◽  
pp. 351-373 ◽  
Author(s):  
Liang-Yu Wu
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Room Temperature ◽  
Migratory Birds ◽  
Local Infection ◽  
Domestic Ducks ◽  
Ottawa River ◽  
Daughter Sporocyst ◽  
Physa Gyrina ◽  
History Of

A cause of swimmer's itch in the lower Ottawa River is Trichobilharzia cameroni sp. nov. Its life cycle has been completed experimentally in laboratory-bred snails and in canaries and ducks, and the various stages are described. The eggs are spindle-shaped. The sporocysts are colorless and tubular. Mother sporocysts become mature in about a week. The younger daughter sporocyst is provided with spines on the anterior end and becomes mature in about three weeks. The development in the snail requires from 28 to 35 days. A few cercariae were found to live for up to 14 days at 50 °C., although their life at 16° to 18 °C. was about four days. Cercariae kept at room temperature for 60 to 72 hr. were found infective. The adults become mature in canaries and pass eggs in about 12 to 14 days. Physa gyrina is the species of snail naturally infected. It was found in one case giving off cercariae for five months after being kept in the laboratory. Domestic ducks were found to become infected until they were at least four months old, with the parasites developing to maturity in due course; no experiments were made with older ducks. Furthermore, miracidia were still recovered from the faeces four months after the duck had been experimentally infected, and it is suggested that migratory birds are the source of the local infection.

Study of Antioxidant Property of the Rhizome Extract of Polygonatum cirrhifolium (Mahameda) and its use in the green synthesis of Gold nanoparticles

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Braja Gopal Bag ◽  
Shib Shankar Dash ◽  
Anup Mandal
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Room Temperature ◽  
Chemical Constituents ◽  
Antioxidant Property ◽  
Dpph Radical ◽  
Mild Conditions ◽  
One Step ◽  
The One

The antioxidant efficacy of the rhizome extract of Polygonatum cirrhifolium (Mahameda) has been studied against a stable 2, 2-diphenylpicrylhydrazyl (DPPH) radical at room temperature. The chemical constituents present in the rhizome extract have been utilized for the one step synthesis of stable gold nanoparticles at room temperature under very mild conditions.

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