Accelerated Color Change of Gold Nanoparticles Assembled by DNAzymes for Simple and Fast Colorimetric Pb2+Detection

AuNPs, capped with anti-8-OHdG antibody, aggregate when 8-OHdG was added, resulting in color change and redshift of absorption wavelength. So a simple and rapid method to selectively determine 8-OHdG was developed and semi-quantitative determination could be achieved by the naked eye.

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Preparation of Poly(Acrylic Acid) Crosslinked-Gold Nanoparticles for Colorimetric Detection of Analytes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.950.138 ◽

2019 ◽

Vol 950 ◽

pp. 138-143

Author(s):

Erindyah Retno Wikantyasning ◽

Mutmainnah Mutmainnah ◽

Ghiyats Ramadhan ◽

Zakky Cholisoh ◽

Muhammad Da'i

Keyword(s):

Gold Nanoparticles ◽

Herbal Medicine ◽

Acrylic Acid ◽

Color Change ◽

Colorimetric Detection ◽

Ph Responsive ◽

Herbal Medicine Product ◽

Responsive Polymer ◽

Medicine Product ◽

Poly Acrylic Acid

The aims of this study are to synthesize and characterize gold nanoparticles (AuNPs) crosslinked by pH-responsive polymer poly (acrylic acid) (PAA) and its application for detection of some analytes in herbal medicine product. In this study, a pH-responsive polymer, poly (acrylic acid) was prepared by the reversible addition-fragmentation chain transfer (RAFT) polymerization method. The polymer was then cross-linked by gold nanoparticles, which was synthesized by the Turkevich method. The response of the AuNPs-crosslinked PAA was observed by the color change from red to blue at a specific pH (4-5) and was characterized by TEM. The reversible color change was resulted from aggregation and disaggregation of the AuNPs due to the shrinking and swelling of the polymer when different pH was introduced as a stimulant. This sensor has the capability of recognizing analytes such as aspirin and tolbutamide added in the herbal medicine product at the concentration of 0.04-0.05 M.

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Facile and One Pot Synthesis of Gold Nanoparticles Using Tetraphenylborate and Polyvinylpyrrolidone for Selective Colorimetric Detection of Mercury Ions in Aqueous Medium

Journal of Analytical Methods in Chemistry ◽

10.1155/2012/348965 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 14

Author(s):

Sidhureddy Boopathi ◽

Shanmugam Senthilkumar ◽

Kanala Lakshminarasimha Phani

Keyword(s):

Gold Nanoparticles ◽

Alkaline Medium ◽

Color Change ◽

Colorimetric Detection ◽

Spherical Shape ◽

Reducing Agent ◽

Nanoparticle Dispersion ◽

Mercury Ions ◽

One Pot ◽

Resonance Band

In this work, we reported for the first time, a facile and one step synthesis of gold nanoparticles from HAuCl4, employing tetraphenylborate as the reducing agent. The synthesis is not only facile but also yields “dumb-bell-shaped”particles. This shape appears to arise from a possible emulsion of the products of oxidation/decomposition of tetraphenylborate by HAuCl4, surrounding the particle. The size and shape of the AuNPs were characterized by Transmission electron microscopy (TEM) and UV-visible Spectroscopy. Interestingly, the addition of polyvinylpyrrolidone (PVP) during the synthesis was found to enhance the stability of the nanoparticle dispersion. The particles synthesized under these conditions assume “spherical” shape with the appearance of only transverse surface plasmon resonance band. The highlight of the observations is that the gold nanoparticles synthesized using tetraphenylborate as reducing agent and PVP as stabilizer are highly stable in alkaline medium, in contrast to the synthesis wherein borohydride is used as reducing agent. The AuNPs synthesized using tetraphenylborate and PVP show their mercury sensing behavior only in the alkaline medium. The color of the nanoparticle dispersion undergoes distinct color change from pink to blue with the addition of mercury ions. They also show dramatic selectivity to mercury ions in presence of other interfering ions, Pb2+, Zn2+and Ca2+.

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Gold nanoparticles functionalized with 2,6-dimercaptopurine for sensitive and selective colorimetric determination of cadmium(ii) in food, biological and environmental samples

Analytical Methods ◽

10.1039/c7ay01871a ◽

2017 ◽

Vol 9 (38) ◽

pp. 5598-5603 ◽

Cited By ~ 5

Author(s):

M. H. Hu ◽

W. H. Huang ◽

L. L. Suo ◽

L. H. Zhou ◽

L. F. Ma ◽

...

Keyword(s):

Gold Nanoparticles ◽

Environmental Samples ◽

Color Change ◽

Colorimetric Determination ◽

Biological And Environmental Samples

The proposed method can recognize Cd2+in different samples based on the aggregation of DMP-AuNPs, resulting in a color change.

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A Highly Sensitive and Selective Colorimetric Hg2+ Ion Probe Using Gold Nanoparticles Functionalized with Polyethyleneimine

Journal of Analytical Methods in Chemistry ◽

10.1155/2018/1206913 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Kyung Min Kim ◽

Yun-Sik Nam ◽

Yeonhee Lee ◽

Kang-Bong Lee

Keyword(s):

Gold Nanoparticles ◽

Secondary Ion Mass Spectrometry ◽

Color Change ◽

Colorimetric Assay ◽

Tap Water ◽

Interparticle Distance ◽

Pond Water ◽

Assay Method ◽

Tuna Fish ◽

Highly Sensitive

A highly sensitive and selective colorimetric assay for the detection of Hg2+ ions was developed using gold nanoparticles (AuNPs) conjugated with polyethyleneimine (PEI). The Hg2+ ion coordinates with PEI, decreasing the interparticle distance and inducing aggregation. Time-of-flight secondary ion mass spectrometry showed that the Hg2+ ion was bound to the nitrogen atoms of the PEI in a bidentate manner (N–Hg2+–N), which resulted in a significant color change from light red to violet due to aggregation. Using this PEI-AuNP probe, determination of Hg2+ ion can be achieved by the naked eye and spectrophotometric methods. Pronounced color change of the PEI-AuNPs in the presence of Hg2+ was optimized at pH 7.0, 50°C, and 300 mM·NaCl concentration. The absorption intensity ratio (A700/A514) was correlated with the Hg2+ concentration in the linear range of 0.003–5.0 μM. The limits of detection were measured to be 1.72, 1.80, 2.00, and 1.95 nM for tap water, pond water, tuna fish, and bovine serum, respectively. Owing to its facile and sensitive nature, this assay method for Hg2+ ions can be applied to the analysis of water and biological samples.

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PLASMON ABSORPTION OF GOLD NANOPARTICLES AND THEIR MORPHOLOGIES OBSERVED BY AFM

Surface Review and Letters ◽

10.1142/s0218625x96002060 ◽

1996 ◽

Vol 03 (01) ◽

pp. 1153-1156 ◽

Cited By ~ 8

Author(s):

H. ISHIKAWA ◽

T. IDA ◽

K. KIMURA

Keyword(s):

Heat Treatment ◽

Gold Nanoparticles ◽

Atomic Force Microscopy ◽

Absorption Spectrum ◽

Color Change ◽

Island Film ◽

Plasmon Absorption ◽

Force Microscopy ◽

Atomic Force

We have studied the effect of heat treatment on Au-island film prepared by a sputtering method, atomic force microscopy (AFM), and UV-VIS spectrophotometry. The structure and absorption spectrum of Au-island film are significantly changed by heat treatment, which corresponds to the visible color change from blue to red. In order to elucidate the relation between the structural and optical changes, we have simulated the change of spectrum using the Maxwell-Garnett theory. The calculated spectra are qualitatively in agreement with the experimental spectra.

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A universal strategy for visual chiral recognition of α-amino acids with l-tartaric acid-capped gold nanoparticles as colorimetric probes

The Analyst ◽

10.1039/c5an02434j ◽

2016 ◽

Vol 141 (4) ◽

pp. 1257-1265 ◽

Cited By ~ 29

Author(s):

Guoxin Song ◽

Fulin Zhou ◽

Chunli Xu ◽

Baoxin Li

Keyword(s):

Amino Acids ◽

Gold Nanoparticles ◽

Tartaric Acid ◽

Chiral Recognition ◽

Color Change ◽

Blue Color ◽

Left Handed

All of 19 right-handed α-amino acids can induce a red-to-blue color change of l-tartaric acid-capped AuNP solution, whereas all of the left-handed amino acids (except cysteine) cannot.

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Synthesis of Gold Nanoparticles Using Glutamic Acid as a Reductor and Capping Agent

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.840.472 ◽

2020 ◽

Vol 840 ◽

pp. 472-477

Author(s):

Naura Nadhifah ◽

Wening Rara Pratita ◽

Eko Sri Kunarti ◽

Nuryono Nuryono ◽

Sri Juari Santosa

Keyword(s):

Gold Nanoparticles ◽

Acid Solution ◽

Glutamic Acid ◽

Color Change ◽

Reaction Times ◽

Chloroauric Acid ◽

Optimum Synthesis ◽

Transmission Electron ◽

Particle Size Analyzer ◽

Uv Visible

The synthesis of gold nanoparticles (AuNPs) was carried out by reacting chloroauric acid [AuCl4]‒ and glutamic acid solution in a water bath at 80 °C. The reaction was confirmed by the color change from colorless solution into pink. Various concentrations of the glutamic acid solution, reaction times and pH were examined to determine the optimum condition of AuNPs synthesis. The AuNPs colloid was characterized by UV-Visible spectrophotometer at wavelength 350-800 nm, particle size analyzer (PSA) and transmission electron microscope (TEM). The optimum synthesis condition for obtained [AuCl4]‒ was 4 mM glutamic acid solution at pH 11 and 60 min reaction. TEM results showed that the particles were round in shape with the article size indicated by PSA was 40 nm.

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