Preparation of gold nanoparticles using pyridine-formaldehyde as a reducing agent and its application in high sensitivity colorimetric detection of Pb2+

2019 ◽  
Vol 11 (34) ◽  
pp. 4362-4369 ◽  
Author(s):  
Liling Lei ◽  
Haimei Song ◽  
Junhong Zhao ◽  
Qingxiang Yang ◽  
Zhijun Chen

A new method for preparing AuNPs has been successfully developed by using pyridine-formaldehyde as reducing agent. The AuNPs were used in colorimetric sensor for detection of Pb2+ in aqueous solutions.

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Sidhureddy Boopathi ◽  
Shanmugam Senthilkumar ◽  
Kanala Lakshminarasimha Phani

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+.


2017 ◽  
Vol 41 (19) ◽  
pp. 10592-10597 ◽  
Author(s):  
Fei Qu ◽  
Yanqun Liu ◽  
Haili Lao ◽  
Yaping Wang ◽  
Jinmao You

The negatively charged heparin hinders the aggregation of Au nanoparticles induced by the cationic polymer nanodots.


RSC Advances ◽  
2018 ◽  
Vol 8 (38) ◽  
pp. 21566-21576 ◽  
Author(s):  
Siwat Plaisen ◽  
Wilairat Cheewasedtham ◽  
Thitima Rujiralai

In this work, we developed a AuNP colorimetric sensor for the facile, sensitive and selective detection of bromide ions in rice samples.


2012 ◽  
Vol 4 (5) ◽  
pp. 1259 ◽  
Author(s):  
Junwei Xin ◽  
Lijing Miao ◽  
Shougang Chen ◽  
Aiguo Wu

2016 ◽  
Vol 8 (11) ◽  
pp. 2494-2501 ◽  
Author(s):  
Rong Sheng Li ◽  
Hai Liu ◽  
Bin Bin Chen ◽  
Hong Zhi Zhang ◽  
Cheng Zhi Huang ◽  
...  

In this work, stable gold nanoparticles (AuNPs) were prepared with good compatibility and favorable catalytic activity. They were developed as a peroxidase mimic for colorimetric detection of cysteine with a weakened blue solution, which supplied high sensitivity and selectivity.


2019 ◽  
Vol 11 (29) ◽  
pp. 3706-3713 ◽  
Author(s):  
Mohammed Awad Abedalwafa ◽  
Yan Li ◽  
Chunfang Ni ◽  
Gang Yang ◽  
Lu Wang

Non-enzymatic colorimetric sensor strip for detection of metronidazole (MTZ) was designed and constructed, with high sensitivity and selectivity. Which can be used for naked-eye detection of MTZ with a visible color change from pink to purple.


Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 38
Author(s):  
Jingyang Zhu ◽  
Lifeng Yin ◽  
Weiyi Zhang ◽  
Meilian Chen ◽  
Dongsheng Feng ◽  
...  

Deltamethrin (DEL) is one of the most commonly used pyrethroid pesticides that can cause serious harms to the ecological environment and human health. Herein, we have developed a paper-based colorimetric sensor impregnated with gold nanoparticles (AuNPs) for on-site determination of DEL pesticide. AuNPs show obvious color change on paper device with the presence of DEL. Measuring the gray intensity of the AuNPs on the reaction zone of the paper sensor allows accurate quantitative analysis. The detection mechanism of DEL on paper sensor was confirmed by UV-Vis spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscope (TEM). Under optimal conditions, the colorimetric sensor exhibited high sensitivity, rapid detection, and low detection limit within the values stipulated by Chinese detection standards (LOD = 0.584 mg/L). Besides, detecting DEL in vegetable and fruit samples also gave satisfying results, which were much consistent with those obtained by spectrophotometry. Overall, this work provided a user-friendly, cost-effective and visualized detection platform, which could be applied to rapidly detect DEL pesticides in the food safety field.


2019 ◽  
Vol 7 (22) ◽  
pp. 3576-3581 ◽  
Author(s):  
Xianqi Feng ◽  
Jun Xu ◽  
Yanxia Liu ◽  
Wenpeng Zhao

Possessing the combined advantages of a stable network structure, brilliant structural color, and high sensitivity, the three-dimensional inverse opal hydrogel film could be used as a colorimetric sensor for the precise detection of glucose.


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