Fiber-optics: a new route towards ultra-low detection limit label-free biosensing

2019 ◽  
Author(s):  
Pablo Zubiate ◽  
Desiree Santano ◽  
Aitor Urrutia ◽  
Carlos R. Zamarreño ◽  
Silvia Díaz ◽  
...  
Keyword(s):  
Detection Limit ◽  
Fiber Optics ◽  
Label Free ◽  
Low Detection Limit

A nanofluidic device for ultrasensitive and label-free detection of tetracycline in association with γ-cyclodextrin and GO

2021 ◽  
Vol 13 (15) ◽  
pp. 1832-1838
Author(s):  
Jiaxi Cheng ◽  
Fenghua Jiang ◽  
Siqi Zhang
Keyword(s):  
Detection Limit ◽  
Water Samples ◽  
Recovery Rate ◽  
Label Free ◽  
Detection Range ◽  
Low Detection Limit ◽  
Sensing Platform ◽  
Label Free Detection ◽  
Nanofluidic Device

We develop a label-free, sensitive and selective nanochannel sensing platform for detection of TC. The nanosensor provided a low detection limit, a wide detection range and excellent recovery rate in different water samples.

Label-free colorimetric aptasensor for IgE using DNA pseudoknot probe

The Analyst ◽  
2014 ◽  
Vol 139 (13) ◽  
pp. 3347-3351 ◽  
Author(s):  
Chia-Chen Chang ◽  
Chen-Yu Chen ◽  
Xihong Zhao ◽  
Tzu-Heng Wu ◽  
Shih-Chung Wei ◽  
...  
Keyword(s):  
Detection Limit ◽  
High Selectivity ◽  
Colorimetric Assay ◽  
Simple Design ◽  
Label Free ◽  
Low Detection Limit ◽  
Structure Switching ◽  
Colorimetric Aptasensor

A simple design of a label-free colorimetric assay for IgE was demonstrated based on a structure-switching aptamer with a low detection limit of 0.2 nM and high selectivity.

Insecticide Residues on 1972 U.S. Auction-Market Tobacco

1975 ◽  
Vol 8 (1) ◽  
Author(s):  
J. J. Domanski ◽  
P. L. Haire ◽  
T.J. Sheets
Keyword(s):  
Detection Limit ◽  
Auction Market ◽  
Insecticide Residues ◽  
Low Detection Limit ◽  
Average Residue ◽  
The Individual ◽  
In Fire

AbstractAverage residue Ievels of DDT + TDE in flue-cured tobacco decreased from 6.1 ppm in 1970 to 0.85 ppm in 1972. DDT + TDE residues in Burley also dropped sharply from previous levels. In 1972 one sample from Kentucky contained 8.17 ppm; all other Burley samples were less than 0.25 ppm. DDT + TDE residues also declined in fire-cured and air-cured types; of these samples Tennessee dark air-cured tobacco contained the highest average residue (3.5 ppm of DDT + TDE). In 1972 over 90 % of the flue-cured samples were positive for toxaphene. Since each of our samples was a composite of tobacco from 10 farmers, we cannot conclude from this result that 90 % of the individual piles contained toxaphene. Significant amounts of toxaphene were found in other types also; for example, 50 % of the 1972 Burley samples had toxaphene concentrations greater than 0.5 ppm. Average endosulfan levels decreased between 1970 and 1972 in flue-cured and Burley tobaccos. However, in all of the dark air and dark fire-cured samples from Tennessee endosulfan residues exceeded 5 ppm. Average endrin residues were at or near the low detection limit in alI samples except fire-cured and dark air-cured tobacco from Tennessee; these averaged 0.26 and 0.17 ppm, respectively.

Label-Free Electrochemical Detection of DNA Hybridization Related to Anthrax Lethal Factor by using Carbon Nanotube Modified Sensors

2019 ◽  
Vol 15 (4) ◽  
pp. 502-510 ◽  
Author(s):  
Hakan Karadeniz ◽  
Arzum Erdem
Keyword(s):  
Detection Limit ◽  
Dna Hybridization ◽  
Lethal Factor ◽  
Modified Electrodes ◽  
Label Free ◽  
Carbon Paste ◽  
Chip Technology ◽  
Anthrax Lethal Factor ◽  
Hybridization Time ◽  
Electrochemical Monitoring

Background: Anthrax Lethal Factor (ANT) is the dominant virulence factor produced by B. anthracis and is the major cause of death of infected animals. In this paper, pencil graphite electrodes GE were modified with single-walled and multi-walled carbon nanotubes (CNTs) for the detection of hybridization related to the ANT DNA for the first time in the literature. Methods: The electrochemical monitoring of label-free DNA hybridization related to ANT DNA was explored using both SCNT and MCNT modified PGEs with differential pulse voltammetry (DPV). The performance characteristics of ANT-DNA hybridization on disposable GEs were explored by measuring the guanine signal in terms of optimum analytical conditions; the concentration of SCNT and MCNT, the concentrations of probe and target, and also the hybridization time. Under the optimum conditions, the selectivity of probe modified electrodes was tested and the detection limit was calculated. Results: The selectivity of ANT probes immobilized onto MCNT-GEs was tested in the presence of hybridization of probe with NC no response was observed and with MM, smaller responses were observed in comparison to full-match DNA hybridization case. Even though there are unwanted substituents in the mixture samples containing both the target and NC in the ratio 1:1 and both the target and MM in the ratio 1:1, it has been found that ANT probe immobilized CNT modified graphite sensor can also select its target by resulting with 20.9% decreased response in comparison to the one measured in the case of full-match DNA hybridization case Therefore, it was concluded that the detection of direct DNA hybridization was performed by using MCNT-GEs with an acceptable selectivity. Conclusion: Disposable SCNT/MCNT modified GEs bring some important advantages to our assay including easy use, cost-effectiveness and giving a response in a shorter time compared to unmodified PGE, carbon paste electrode and glassy carbon electrode developed for electrochemical monitoring of DNA hybridization. Consequently, the detection of DNA hybridization related to the ANT DNA by MCNT modified sensors was performed by using lower CNT, probe and target concentrations, in a shorter hybridization time and resulting in a lower detection limit according to the SCNT modified sensors. In conclusion, MCNT modified sensors can yield the possibilities leading to the development of nucleic acid sensors platforms for the improvement of fast and cost-effective detection systems with respect to DNA chip technology.

A simple method to construct a low-cost immunosensor based on a dithiol-functionalized polydopamine platform

2021 ◽  
Author(s):  
Bo Liu ◽  
Luanying Yang ◽  
Gang Wang ◽  
Sha He ◽  
Xiaobo Wang ◽  
...  
Keyword(s):  
Detection Limit ◽  
Linear Response ◽  
Low Cost ◽  
Covalent Immobilization ◽  
The Self ◽  
Simple Method ◽  
Low Detection Limit

A simple and low-cost electrochemical CEA immunosensor was investigated via the self-polymerization of dopamine and a dithiol compound spacer for the covalent immobilization of antibodies. The designed CEA immunosensor exhibited a linear response and a low detection limit.

An ultra-highly sensitive and selective self-enhanced AIECL sensor for public security early warning in a nuclear emergency via a co-reactive group poisoning mechanism

2021 ◽  
Author(s):  
Ziyu Wang ◽  
Meiyun Xu ◽  
Nan Zhang ◽  
Jian-Bin Pan ◽  
Xinqi Wu ◽  
...  
Keyword(s):  
Detection Limit ◽  
Early Warning ◽  
High Selectivity ◽  
Public Security ◽  
Reactive Group ◽  
Low Detection Limit ◽  
Highly Sensitive ◽  
Vapor Sensors ◽  
Nuclear Emergency

A mechanism of co-reactive group poisoning (CGP) was discovered for designing efficient I2 vapor sensors for early warning of a nuclear emergency, which give an ultra-low detection limit of 0.13 ppt as well as high selectivity.

Bifunctional 4MBA mediated recyclable SERS-based immunoassay induced by photocatalytic activity of TiO2 nanotube arrays

2016 ◽  
Vol 18 (34) ◽  
pp. 23795-23802 ◽  
Author(s):  
Xiaolong Wang ◽  
Lu Zhou ◽  
Wei Lai ◽  
Tao Jiang ◽  
Jun Zhou
Keyword(s):  
Density Functional Theory ◽  
Photocatalytic Activity ◽  
Detection Limit ◽  
Uv Irradiation ◽  
Density Functional ◽  
Tio2 Nanotube Arrays ◽  
Tio2 Nanotube ◽  
Nanotube Arrays ◽  
Functional Theory ◽  
Low Detection Limit

We present a recyclable SERS-based immunoassay for CA19-9 with a low detection limit of 5 U mL−1. The linking between TiO2-NTs and 4MBA was destroyed by catalyzing 4MBA into 4-sulfobenzoate upon UV irradiation, which was clarified by UPLC/ESI-tqMS and density functional theory.

Electrochemical investigations of 8-hydroxydeoxyguanosine and its determination at an edge plane pyrolytic graphite electrode

RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 1722-1728 ◽  
Author(s):  
Pankaj Gupta ◽  
Munetaka Oyama ◽  
Rajendra N. Goyal
Keyword(s):  
Detection Limit ◽  
Electrochemical Oxidation ◽  
Graphite Electrode ◽  
Pyrolytic Graphite ◽  
Low Detection Limit ◽  
Pyrolytic Graphite Electrode

Electrochemical oxidation of 8-hydroxydeoxyguanosine (8-OHdG) and its detection with low detection limit is reported at pyrolytic graphite electrode.

An ultrasensitive electrochemical immunosensor for the detection of CD146 based on TiO2 colloidal sphere laden Au/Pd nanoparticles

The Analyst ◽  
2015 ◽  
Vol 140 (10) ◽  
pp. 3557-3564 ◽  
Author(s):  
Yaoguang Wang ◽  
Yueyun Li ◽  
Hongmin Ma ◽  
Aiping Guo ◽  
Bin Du ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Detection Limit ◽  
Pd Nanoparticles ◽  
Electrochemical Immunosensor ◽  
Loading Capacity ◽  
Colloidal Sphere ◽  
Low Detection Limit

An ultrasensitive electrochemical immunosensor was developed for detecting CD146. rGO-TEPA enhanced the loading capacity of Ab1 and facilitated the electron transfer. Au and Pd nanoparticles on the TiO2 colloidal sphere facilitated the decomposition of H2O2. The immunosensor exhibited an extremely low detection limit of 1.6 pg mL−1 for CD146.

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