A Rapid and Sensitive Aptasensor for Cyromazine Detection in Raw Milk Based on a Nanogold Probe and G-Quadruplex Formation

2019 ◽  
Vol 72 (7) ◽  
pp. 555
Author(s):  
Xu Dang ◽  
Wenchao Gu ◽  
Xiyin Zheng ◽  
Xuelian Fei ◽  
Fuxiang Tian ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Limit Of Detection ◽  
Raw Milk ◽  
Cationic Polymer ◽  
Remarkable Change ◽  
Detection Range ◽  
Naked Eye ◽  
Diallyldimethylammonium Chloride ◽  
G Quadruplex ◽  
Quadruplex Formation

Herein, a rapid, facile, and colourimetric sensor for the detection of cyromazine in raw milk is reported using an aptamer based on gold nanoparticles (AuNPs). A sequence-specific aptamer for cyromazine called Tcyr1 is designed to absorb on the surface of AuNPs and electrostatically interacts with poly(diallyldimethylammonium chloride) (PDDA), which prevents AuNPs from aggregating. It can also self-assemble to form a G-quadruplex-CYR complex with cyromazine. Because of its specificity and stability, the introduction of cyromazine in raw milk would influence the protection thus the following cationic polymer could aggregate AuNPs and cause a remarkable change in colour. According to this, the presence of cyromazine can be determined by the naked eye and means of absorbance. This sensor is selective for the detection of cyromazine in raw milk and has a limit of detection of 200 ppb by the naked eye and of 5.8 ppb by spectrophotometer, and has a detection range from 0.1 to 1 ppm.

A Label-Free Colorimetric Biosensor for 17β-Estradiol Detection Using Nanoparticles Assembled by Aptamer and Cationic Polymer

2016 ◽  
Vol 69 (1) ◽  
pp. 12 ◽  
Author(s):  
Dongwei Zhang ◽  
Weilin Zhang ◽  
Jiayun Ye ◽  
Shenshan Zhan ◽  
Bing Xia ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Colorimetric Detection ◽  
Cationic Polymer ◽  
Label Free ◽  
Human Beings ◽  
Remarkable Change ◽  
Environment Effects ◽  
Diallyldimethylammonium Chloride ◽  
17Β Estradiol

Concern is mounting regarding the human health and environment effects of 17β-estradiol (E2), a natural oestrogen excreted by human beings and animals. In this paper, a sensitive and selective biosensor for the detection of E2 using gold nanoparticles (AuNPs), label-free E2-specific aptamer, and poly(diallyldimethylammonium chloride) (PDDA) was developed. In the absence of E2, PDDA can electrostatically interact with E2-specific aptamer, and the charge responsible for inducing AuNPs aggregation was destroyed. However, the introduction of E2 can specifically interact with the aptamer to form E2–aptamer complex so that PDDA can aggregate AuNPs and cause a remarkable change in colour from wine red to blue, which enables colorimetric detection of E2 with selectivity and a detection limit of 1.57 nM.

scholarly journals Instrumentation-Free Semiquantitative Immunoanalysis Using a Specially Patterned Lateral Flow Assay Device

Biosensors ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 87
Author(s):  
Kyung Won Lee ◽  
Ye Chan Yu ◽  
Hyeong Jin Chun ◽  
Yo Han Jang ◽  
Yong Duk Han ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Optical Probe ◽  
Lateral Flow ◽  
Analyte Concentration ◽  
Detection Range ◽  
Optical Instruments ◽  
Naked Eye ◽  
Resource Limited ◽  
Test Zone ◽  
Artificial Urine

In traditional colorimetric lateral flow immunoassay (LFI) using gold nanoparticles (AuNPs) as a probe, additional optical transducers are required to quantify the signal intensity of the test line because it presents as a single red-colored line. In order to eliminate external equipment, the LFI signal should be quantifiable by the naked eye without the involvement of optical instruments. Given this objective, the single line test zone of conventional LFI was converted to several spots that formed herringbone patterns. When the sandwich immunoassay was performed on a newly developed semi-quantitative (SQ)-LFI system using AuNPs as an optical probe, the spots were colorized and the number of colored spots increased proportionally with the analyte concentration. By counting the number of colored spots, the analyte concentration can be easily estimated with the naked eye. To demonstrate the applicability of the SQ-LFI system in practical immunoanalysis, microalbumin, which is a diagnostic marker for renal failure, was analyzed using microalbumin-spiked artificial urine samples. Using the SQ-LFI system, the calibration results for artificial urine-based microalbumin were studied, ranging from 0 to 500 μg/mL, covering the required clinical detection range, and the limit of detection (LOD) value was calculated to be 15.5 μg/mL. Thus, the SQ-LFI system provides an avenue for the realization of an efficient quantification diagnostic device in resource-limited conditions.

Colorimetric Detection of Melamine Based on Poly-Thymine Stabilized Gold Nanoparticles

2013 ◽  
Vol 790 ◽  
pp. 619-622
Author(s):  
Chong Jin ◽  
Hui Min Zhao ◽  
Meng Liu ◽  
Jun Ping Tian ◽  
Xie Quan
Keyword(s):  
Gold Nanoparticles ◽  
Color Change ◽  
Limit Of Detection ◽  
Pure Water ◽  
Colorimetric Detection ◽  
Colorimetric Method ◽  
Milk Powder ◽  
Aggregation Process ◽  
Naked Eye ◽  
Fresh Milk

A simple, fast and reliable colorimetric method for melamine detection based on gold nanoparticles (AuNPs) and poly-thymine (poly-T) is reported. Poly-T strands attract AuNPs through static electricity and keep them stable against aggregation in the presence of NaCl. The affinity between melamine and poly-T, hydrogen bond, frees AuNP from the protection provided by poly-T and thus makes AuNPs aggregate in the presence of NaCl. The color change of AuNPs from wine red to blue can be observed immediately by the naked eye during the aggregation process, and can be accurately recorded with the help of a UV/vis spetrophotometer within 5 minutes. The limit of detection (LOD) of melamine in pure water is 0.146 μmol/L with a linear range from 0.2×10-7 mol/L to 10.0×10-7 mol/L. In fresh milk and milk powder, the LOD is respectively as low as 2.37 μmol/L and 5.36 μmol/L.

scholarly journals A simple fluorescent assay for cyromazine detection in raw milk by using CYR-stabilized G-quadruplex formation

RSC Advances ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 2418-2425 ◽  
Author(s):  
Haibo Xing ◽  
Wenchao Gu ◽  
Dang Xu ◽  
Fuxiang Tian ◽  
Linyun Yao ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Raw Milk ◽  
Fluorescent Assay ◽  
G Quadruplex ◽  
Quadruplex Formation

A rapid biosensor for the detection of cyromazine in milk is reported based on a fluorescence quenching result.

Indirect Determination of Amikacin by Gold Nanoparticles as Redox Probe

2020 ◽  
Vol 17 ◽  
Author(s):  
Mansureh Alizadeh ◽  
Mandana Amiri ◽  
Abolfazl Bezaatpour
Keyword(s):  
Gold Nanoparticles ◽  
Bacterial Infections ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Cathodic Peak ◽  
Easy Method ◽  
Peak Current ◽  
Indirect Determination ◽  
Tract Infections

: Amikacin is an aminoglycoside antibiotic used for many gram-negative bacterial infections like infections in the urinary tract, infections in brain, lungs and abdomen. Electrochemical determination of amikacin is a challenge in electroanalysis because it shows no voltammetric peak at the surface of bare electrodes. In this approach, a very simple and easy method for indirect voltammetric determination of amikacin presented in real samples. Gold nanoparticles were electrodeposited at the surface of glassy carbon electrode in constant potential. The effect of several parameters such as time and potential of deposition, pH and scan rates on signal were studied. The cathodic peak current of Au3+ decreased with increasing amikacin concentration. Quantitative analysis of amikacin was performed using differential pulse voltammetry by following cathodic peak current of gold ions. Two dynamic linear ranges of 1.0 × 10−8–1.0 × 10-7 M and 5.0 × 10−7–1.0 × 10-3 M were obtained and limit of detection was estimated 3.0× 10−9 M. The method was successfully determined amikacin in pharmaceutical preparation and human serum. The effect of several interference in determination of amikacin was also studied.

scholarly journals A Compact Detection Platform Based on Gradient Guided-Mode Resonance for Colorimetric and Fluorescence Liquid Assay Detection

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2797
Author(s):  
Jing-Jhong Gao ◽  
Ching-Wei Chiu ◽  
Kuo-Hsing Wen ◽  
Cheng-Sheng Huang
Keyword(s):  
Limit Of Detection ◽  
Detection System ◽  
Fluorescence Emission ◽  
Assay Sensitivity ◽  
Detection Range ◽  
Current Form ◽  
Guided Mode ◽  
Spectral Detection ◽  
Guided Mode Resonance ◽  
Colorimetric Assays

This paper presents a compact spectral detection system for common fluorescent and colorimetric assays. This system includes a gradient grating period guided-mode resonance (GGP-GMR) filter and charge-coupled device. In its current form, the GGP-GMR filter, which has a size of less than 2.5 mm, can achieve a spectral detection range of 500–700 nm. Through the direct measurement of the fluorescence emission, the proposed system was demonstrated to detect both the peak wavelength and its corresponding intensity. One fluorescent assay (albumin) and two colorimetric assays (albumin and creatinine) were performed to demonstrate the practical application of the proposed system for quantifying common liquid assays. The results of our system exhibited suitable agreement with those of a commercial spectrometer in terms of the assay sensitivity and limit of detection (LOD). With the proposed system, the fluorescent albumin, colorimetric albumin, and colorimetric creatinine assays achieved LODs of 40.99 and 398 and 25.49 mg/L, respectively. For a wide selection of biomolecules in point-of-care applications, the spectral detection range achieved by the GGP-GMR filter can be further extended and the simple and compact optical path configuration can be integrated with a lab-on-a-chip system.

scholarly journals DNA polymerase δ stalls on telomeric lagging strand templates independently from G-quadruplex formation

2013 ◽  
Vol 41 (22) ◽  
pp. 10323-10333 ◽  
Author(s):  
Justin D. Lormand ◽  
Noah Buncher ◽  
Connor T. Murphy ◽  
Parminder Kaur ◽  
Marietta Y. Lee ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Dna Polymerase Δ ◽  
G Quadruplex ◽  
Quadruplex Formation ◽  
Lagging Strand

scholarly journals Ratiometric Fluorescent Biosensors for Glucose and Lactate Using an Oxygen-Sensing Membrane

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 208
Author(s):  
Hong Dinh Duong ◽  
Jong Il Rhee
Keyword(s):  
Limit Of Detection ◽  
Oxygen Sensing ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Oxidation Reactions ◽  
Lactate Oxidase ◽  
Lactate Oxidation ◽  
Detection Range ◽  
Quenching Effect ◽  
Sensing Membrane

In this study, ratiometric fluorescent glucose and lactate biosensors were developed using a ratiometric fluorescent oxygen-sensing membrane immobilized with glucose oxidase (GOD) or lactate oxidase (LOX). Herein, the ratiometric fluorescent oxygen-sensing membrane was fabricated with the ratio of two emission wavelengths of platinum meso-tetra (pentafluorophenyl) porphyrin (PtP) doped in polystyrene particles and coumarin 6 (C6) captured into silica particles. The operation mechanism of the sensing membranes was based on (i) the fluorescence quenching effect of the PtP dye by oxygen molecules, and (ii) the consumption of oxygen levels in the glucose or lactate oxidation reactions under the catalysis of GOD or LOX. The ratiometric fluorescent glucose-sensing membrane showed high sensitivity to glucose in the range of 0.1–2 mM, with a limit of detection (LOD) of 0.031 mM, whereas the ratiometric fluorescent lactate-sensing membrane showed the linear detection range of 0.1–0.8 mM, with an LOD of 0.06 mM. These sensing membranes also showed good selectivity, fast reversibility, and stability over long-term use. They were applied to detect glucose and lactate in artificial human serum, and they provided reliable measurement results.

Naked-eye colorimetric detection of HCV RNA mediated by a 5′ UTR-targeted antisense oligonucleotide and plasmonic gold nanoparticles

The Analyst ◽  
2021 ◽  
Author(s):  
Almas Shamaila Mohammed ◽  
Aniket Balapure ◽  
Mahammad Nanne Khaja ◽  
Ramakrishnan Ganesan ◽  
Jayati Ray Dutta
Keyword(s):  
Gold Nanoparticles ◽  
Antisense Oligonucleotide ◽  
Early Stage ◽  
Colorimetric Detection ◽  
Sensitive Detection ◽  
Clinical Samples ◽  
Hcv Rna ◽  
Naked Eye

An Au NP based facile strategy for the rapid, early-stage, and sensitive detection of HCV RNA in clinical samples which avoids thiol tagging to the antisense oligonucleotide and expensive infrastructure is presented.

scholarly journals TGF‐β‐induced fibrotic stress increases G‐quadruplex formation in human fibroblasts

FEBS Letters ◽  
2019 ◽  
Vol 593 (22) ◽  
pp. 3149-3161 ◽  
Author(s):  
Priyanka Toshniwal ◽  
Michelle Nguyen ◽  
Aurore Guédin ◽  
Helena Viola ◽  
Diwei Ho ◽  
...  
Keyword(s):  
Human Fibroblasts ◽  
G Quadruplex ◽  
Quadruplex Formation
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