A naked-eye liquid-phase colorimetric assay of simultaneous detect cysteine and lysine

2019 ◽  
Vol 160 ◽  
pp. 151-158 ◽  
Author(s):  
Zhonghua Xue ◽  
Lulu Xiong ◽  
Honghong Rao ◽  
Xiuhui Liu ◽  
Xiaoquan Lu
Keyword(s):  
Liquid Phase ◽  
Colorimetric Assay ◽  
Naked Eye

scholarly journals Instrument-free quantitative gold nanoparticle-based liquid-phase colorimetric assays for use in resource-poor environments

2017 ◽  
Vol 53 (60) ◽  
pp. 8407-8410 ◽  
Author(s):  
Huili Wang ◽  
Yun Zhang ◽  
Rongxing Li ◽  
Jinfang Nie ◽  
Afaf H. El-Sagheer ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Gold Nanoparticle ◽  
Colorimetric Assay ◽  
Quantitative Detection ◽  
Two Dimensional ◽  
New Class ◽  
Naked Eye ◽  
Resource Poor ◽  
Colorimetric Assays

This work describes a new class of gold nanoparticle-based liquid-phase colorimetric assay (GNP-LPCA) termed as two dimensional (2D) GNP-LPCA that enables quantitative detection of model analytes with naked eye.

New two dimensional liquid-phase colorimetric assay based on old iodine–starch complexation for the naked-eye quantitative detection of analytes

2016 ◽  
Vol 52 (47) ◽  
pp. 7454-7457 ◽  
Author(s):  
Jinfang Nie ◽  
Tom Brown ◽  
Yun Zhang
Keyword(s):  
Liquid Phase ◽  
Colorimetric Assay ◽  
Point Of Care ◽  
Low Cost ◽  
Quantitative Detection ◽  
Complexation Reaction ◽  
Two Dimensional ◽  
Eye Detection ◽  
Naked Eye ◽  
Naked Eye Detection

This work describes a new point-of-care two dimensional liquid-phase colorimetric assay (2D LPCA) based on old iodine–starch complexation reaction firstly discovered in 1814 for simple, low-cost, portable, naked-eye detection and quantification of two model analytes.

An ultra-sensitive colorimetric assay for reliable visual detection of telomerase activity

The Analyst ◽  
2017 ◽  
Vol 142 (17) ◽  
pp. 3235-3240 ◽  
Author(s):  
Yaocai Wang ◽  
Luzhu Yang ◽  
Yanjun Wang ◽  
Wei Liu ◽  
Baoxin Li ◽  
...  
Keyword(s):  
Hela Cell ◽  
Visual Detection ◽  
Colorimetric Assay ◽  
Telomerase Activity ◽  
Cell Lysates ◽  
Naked Eye ◽  
Vis Spectroscopy

We proposed a sensitive colorimetric assay for detecting telomerase activity. The telomerase activity of 5 and 20 HeLa cell lysates can be detected via UV-vis spectroscopy and the naked eye, respectively.

Colorimetric detection of class A soybean saponins by coupling DNAzyme with the gap ligase chain reaction

2020 ◽  
Vol 12 (26) ◽  
pp. 3361-3367
Author(s):  
Wenshuai Li ◽  
Guorui Wu ◽  
Min Wang ◽  
Aiqin Yue ◽  
Weijun Du ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Chain Reaction ◽  
Ligase Chain Reaction ◽  
Naked Eye ◽  
Class A

We propose a colorimetric assay based on the coupling of gap ligase chain reaction (Gap-LCR) with DNAzyme to detect the target GmSg-1 genes of class A soybean saponins with the naked eye, without the involvement of expensive instruments.

Visual detection of cancer cells by using in situ grown functional Cu2−xSe/reduced graphene oxide hybrids acting as an efficient nanozyme

The Analyst ◽  
2019 ◽  
Vol 144 (2) ◽  
pp. 716-721 ◽  
Author(s):  
Qing Juan Guo ◽  
Zi Yu Pan ◽  
Chen Men ◽  
Wen Yi Lv ◽  
Hong Yan Zou ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Cancer Cells ◽  
Reduced Graphene Oxide ◽  
Visual Detection ◽  
Colorimetric Assay ◽  
Signal Transducer ◽  
Naked Eye ◽  
Reduced Graphene ◽  
Se Nanoparticles

Cu2−xSe nanoparticles grown in situ on reduced graphene oxide (Cu2−xSe/rGO) acted as an efficient nanozyme. Using the Cu2−xSe/rGO as a signal transducer, a colorimetric assay for cancer cells with the naked eye has been developed.

scholarly journals Polyol-Mediated Synthesis of Nitrogen-Containing Carbon-Dots from Tetracyanobenzene with Intense Red Fluorescence

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1470 ◽  
Author(s):  
Roman Lehmacher ◽  
Claus Feldmann
Keyword(s):  
Polyethylene Glycol ◽  
Liquid Phase ◽  
Quantum Yield ◽  
Carbon Dots ◽  
Emission Spectra ◽  
Excitation Wavelength ◽  
Polyethylene Glycol 400 ◽  
Strong Emission ◽  
Red Emission ◽  
Naked Eye

Nitrogen-containing C-dots were prepared by heating (160 °C, 1 h) 1,2,4,5-tetracyanobenzene (TCB) in polyethylene glycol 400 (PEG400). The as-prepared monocrystalline C-dots were 2–4 nm in diameter and contained 24.4 wt. % of nitrogen. They showed intense fluorescence under excitation at 400–500 nm as well as under excitation at 600–700 nm. In addition to an excitation-wavelength-depending emission at 400 to 650 nm, the emission spectra exhibited a strong emission peaking at 715 nm, whose position was independent from the wavelength of excitation. For this deep-red emission a remarkable quantum yield of 69% was detected. The synthesis of nitrogen-containing C-dotswas completely performed in the liquid phase. Moreover, the C-dots could be directly dispersed in water. The resulting aqueous suspensions of PEG400-stabilized nitrogen-containing C-dots also showed intense red emission that was visible to the naked eye.

scholarly journals Portable on-chip colorimetric biosensing platform integrated with a smartphone for label/PCR-free detection of Cryptosporidium RNA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
George S. Luka ◽  
Ephraim Nowak ◽  
Quin Robert Toyata ◽  
Nishat Tasnim ◽  
Homayoun Najjaran ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Color Change ◽  
Colorimetric Assay ◽  
Cost Effective ◽  
Naked Eye ◽  
Sensing Platform ◽  
3D Printed ◽  
Protozoan Pathogen ◽  
On Chip ◽  
Colorimetric Biosensing

AbstractCryptosporidium, a protozoan pathogen, is a leading threat to public health and the economy. Herein, we report the development of a portable, colorimetric biosensing platform for the sensitive, selective and label/PCR-free detection of Cryptosporidium RNA using oligonucleotides modified gold nanoparticles (AuNPs). A pair of specific thiolated oligonucleotides, complementary to adjacent sequences on Cryptosporidium RNA, were attached to AuNPs. The need for expensive laboratory-based equipment was eliminated by performing the colorimetric assay on a micro-fabricated chip in a 3D-printed holder assembly. A smartphone camera was used to capture an image of the color change for quantitative analysis. The detection was based on the aggregation of the gold nanoparticles due to the hybridization between the complementary Cryptosporidium RNA and the oligonucleotides immobilized on the AuNPs surface. In the complementary RNA’s presence, a distinctive color change of the AuNPs (from red to blue) was observed by the naked eye. However, in the presence of non-complementary RNA, no color change was observed. The sensing platform showed wide linear responses between 5 and 100 µM with a low detection limit of 5 µM of Cryptosporidium RNA. Additionally, the sensor developed here can provide information about different Cryptosporidium species present in water resources. This cost-effective, easy-to-use, portable and smartphone integrated on-chip colorimetric biosensor has great potential to be used for real-time and portable POC pathogen monitoring and molecular diagnostics.

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