Rapid detection of dibutyl phthalate in liquor by a semi-quantitative multicolor immunosensor with naked eyes as readout

2019 ◽  
Vol 11 (4) ◽  
pp. 524-529 ◽  
Author(s):  
Yanling Huang ◽  
Yue Lin ◽  
Fang Luo ◽  
Peilong Wang ◽  
Jian Wang ◽  
...  

A multicolor competitive immunosensor for DBP detection has been proposed based on the etching of gold nanorods (GNRs) using naked eyes as readout.

2020 ◽  
Vol 10 (10) ◽  
pp. 3654
Author(s):  
Hang Nguyen Thi Nhat ◽  
Ngoc Thuy Trang Le ◽  
Nguyen Thi Phuong Phong ◽  
Dai Hai Nguyen ◽  
Minh-Tri Nguyen-Le

The use of gold nanorods (AuNRs) as surface-enhanced Raman scattering (SERS) substrates has gained much attraction due to their remarkably aspect-ratio-dependent plasmonic properties. In this report, we described the development of AuNRs with a high aspect ratio and longitudinal surface plasmon resonance (LSPR) >850 nm through a hydroquinone-based fabrication with minor modifications. The synthesis started with the reduction of chloroauric acid (HAuCl4) by sodium borohydride (NaBH4) to make gold nanoseeds from which AuNRs were grown with the aid of silver nitrate (AgNO3), HAuCl4, cetyltrimethylammonium bromide (CTAB), and hydroquinone (HQ). Scanning electron microscopy coupled with energy-dispersive X-ray (SEM-EDX), Transmission electron microscope (TEM), X-ray diffraction (XRD) and Ultra-violet-Visible spectroscopy (UV-Vis) were performed to study the shape, size, and structural and optical properties of AuNRs, respectively. The results showed that AuNRs with high aspect ratios (AR > 3) were single crystals with a heterogenous size distribution, and that the growth of Au nanoseeds into AuNRs took place along the [001] direction. AuNRs exhibited two plasmon resonance peaks at 520 nm and 903 nm, while gold nanoseeds had only a plasmon resonance peak at 521 nm. The as-synthesized AuNRs also showed SERS effects for thiophanate methyl, a broad-spectrum fungicide, with the limit of detection down to 5 mg/L of the fungicide. AuNR-coated glass can serve as a SERS-based sensing platform for rapid detection of thiophanate methyl with high sensitivity and reproducibility.


2019 ◽  
Vol 1048 ◽  
pp. 154-160 ◽  
Author(s):  
Yushen Liu ◽  
Juan Wang ◽  
Chao Zhao ◽  
Xiaoxiao Guo ◽  
Xiuling Song ◽  
...  

2014 ◽  
Vol 55 ◽  
pp. 242-248 ◽  
Author(s):  
Yashan Wang ◽  
Daohong Zhang ◽  
Wei Liu ◽  
Xiao Zhang ◽  
Shaoxuan Yu ◽  
...  

Author(s):  
O. E. Bradfute

Electron microscopy is frequently used in preliminary diagnosis of plant virus diseases by surveying negatively stained preparations of crude extracts of leaf samples. A major limitation of this method is the time required to survey grids when the concentration of virus particles (VPs) is low. A rapid survey of grids for VPs is reported here; the method employs a low magnification, out-of-focus Search Mode similar to that used for low dose electron microscopy of radiation sensitive specimens. A higher magnification, in-focus Confirm Mode is used to photograph or confirm the detection of VPs. Setting up the Search Mode by obtaining an out-of-focus image of the specimen in diffraction (K. H. Downing and W. Chiu, private communications) and pre-aligning the image in Search Mode with the image in Confirm Mode facilitates rapid switching between Modes.


Author(s):  
C.D. Humphrey ◽  
T.L. Cromeans ◽  
E.H. Cook ◽  
D.W. Bradley

There is a variety of methods available for the rapid detection and identification of viruses by electron microscopy as described in several reviews. The predominant techniques are classified as direct electron microscopy (DEM), immune electron microscopy (IEM), liquid phase immune electron microscopy (LPIEM) and solid phase immune electron microscopy (SPIEM). Each technique has inherent strengths and weaknesses. However, in recent years, the most progress for identifying viruses has been realized by the utilization of SPIEM.


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