scholarly journals Highly Sensitive Fluorescence Sensor for Carrageenan from a Composite Methylcellulose/Polyacrylate Membrane

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5043
Author(s):  
Riyadh Abdulmalek Hassan ◽  
Lee Yook Heng ◽  
Ling Ling Tan
Keyword(s):  
Composite Membrane ◽  
Optical Sensors ◽  
Optical Sensor ◽  
Detrimental Effect ◽  
Acrylic Polymer ◽  
Sulphated Polysaccharides ◽  
Highly Sensitive ◽  
Confectionery Products ◽  
Linear Manner ◽  
Better Than

Carrageenans are linear sulphated polysaccharides that are commonly added into confectionery products but may exert a detrimental effect to human health. A new and simpler way of carrageenan determination based on an optical sensor utilizing a methylcellulose/poly(n-butyl acrylate) (Mc/PnBA) composite membrane with immobilized methylene blue (MB) was developed. The hydrophilic Mc polymer membrane was successfully modified with a more hydrophobic acrylic polymer. This was to produce an insoluble membrane at room temperature where MB reagent could be immobilized to build an optical sensor for carrageenan analysis. The fluorescence intensity of MB in the composite membrane was found to be proportional to the carrageenan concentrations in a linear manner (1.0–20.0 mg L−1, R2 = 0.992) and with a detection limit at 0.4 mg L−1. Recovery of spiked carrageenan into commercial fruit juice products showed percentage recoveries between 90% and 102%. The optical sensor has the advantages of improved sensitivity and better selectivity to carrageenan when compared to other types of hydrocolloids. Its sensitivity was comparable to most sophisticated techniques for carageenan analysis but better than other types of optical sensors. Thus, this sensor provides a simple, rapid, and sensitive means for carageenan analysis.

A Three-Dimensional Tetraphenylethylene-Based Fluorescence Covalent Organic Framework for Molecular Recognition

2020 ◽  
Author(s):  
Junxia Ren ◽  
Yaozu Liu ◽  
Xin Zhu ◽  
Yangyang Pan ◽  
Yujie Wang ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Fluorescence Probe ◽  
Three Dimensional ◽  
Hazardous Substances ◽  
Covalent Organic Framework ◽  
Highly Sensitive ◽  
Volatile Organic ◽  
Polycyclic Aromatic ◽  
Better Than ◽  
Organic Framework

<p><a></a><a></a><a></a><a></a><a></a><a></a><a></a><a>The development of highly-sensitive recognition of </a><a></a><a></a><a></a><a></a><a>hazardous </a>chemicals, such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), is of significant importance because of their widespread social concerns related to environment and human health. Here, we report a three-dimensional (3D) covalent organic framework (COF, termed JUC-555) bearing tetraphenylethylene (TPE) side chains as an aggregation-induced emission (AIE) fluorescence probe for sensitive molecular recognition.<a></a><a> </a>Due to the rotational restriction of TPE rotors in highly interpenetrated framework after inclusion of dimethylformamide (DMF), JUC-555 shows impressive AIE-based strong fluorescence. Meanwhile, owing to the large pore size (11.4 Å) and suitable intermolecular distance of aligned TPE (7.2 Å) in JUC-555, the obtained material demonstrates an excellent performance in the molecular recognition of hazardous chemicals, e.g., nitroaromatic explosives, PAHs, and even thiophene compounds, via a fluorescent quenching mechanism. The quenching constant (<i>K</i><sub>SV</sub>) is two orders of magnitude better than those of other fluorescence-based porous materials reported to date. This research thus opens 3D functionalized COFs as a promising identification tool for environmentally hazardous substances.</p>

scholarly journals Highly sensitive and selective liquid crystal optical sensor for detection of ammonia

2017 ◽  
Vol 25 (12) ◽  
pp. 13549 ◽  
Author(s):  
Xiaofang Niu ◽  
Yuanbo Zhong ◽  
Rui Chen ◽  
Fei Wang ◽  
Dan Luo
Keyword(s):  
Liquid Crystal ◽  
Optical Sensor ◽  
Highly Sensitive

Highly Sensitive Nanoscale Optical Sensor Based on Plasmonic Nanocavity Array

2020 ◽  
Author(s):  
Yunjie Shi ◽  
Guangyuan Li ◽  
Guoquan Liu ◽  
Liang Zhang ◽  
Degui Sun ◽  
...  
Keyword(s):  
Optical Sensor ◽  
Highly Sensitive

A rapid and accurate method for screening T-2 toxin in food and feed using competitive AlphaLISA

2021 ◽  
Vol 368 (6) ◽  
Author(s):  
Liwen Zhang ◽  
Qingyu Lv ◽  
Yuling Zheng ◽  
Xuan Chen ◽  
Decong Kong ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Accurate Method ◽  
Detection Methods ◽  
Cereal Crops ◽  
Detection Range ◽  
Highly Sensitive ◽  
Food And Feed ◽  
Good Repeatability ◽  
Feed Samples ◽  
Better Than

ABSTRACT T-2 is a common mycotoxin contaminating cereal crops. Chronic consumption of food contaminated with T-2 toxin can lead to death, so simple and accurate detection methods in food and feed are necessary. In this paper, we establish a highly sensitive and accurate method for detecting T-2 toxin using AlphaLISA. The system consists of acceptor beads labeled with T-2-bovine serum albumin (BSA), streptavidin-labeled donor beads and biotinylated T-2 antibodies. T-2 in the sample matrix competes with T-2-BSA for antibodies. Adding biotinylated antibodies to the test well followed by T-2 and T-2-BSA acceptor beads yielded a detection range of 0.03–500 ng/mL. The half-maximal inhibitory concentration was 2.28 ng/mL and the coefficient of variation was &lt;10%. In addition, this method had no cross-reaction with other related mycotoxins. This optimized method for extracting T-2 from food and feed samples achieved a recovery rate of approximately 90% in T-2 concentrations as low as 1 ng/mL, better than the performance of a commercial ELISA kit. This competitive AlphaLISA method offers high sensitivity, good specificity, good repeatability and simple operation for detecting T-2 toxin in food and feed.

Laser-written nanoporous silicon ridge waveguide for highly sensitive optical sensors

2012 ◽  
Vol 37 (2) ◽  
pp. 256 ◽  
Author(s):  
Jinan Xia ◽  
Andrea M. Rossi ◽  
Thomas E. Murphy
Keyword(s):  
Optical Sensors ◽  
Ridge Waveguide ◽  
Nanoporous Silicon ◽  
Highly Sensitive

scholarly journals Effect of combination of dye carotene and phycocyanin using daucus carota and spirulina sp. on optical sensor performance

2020 ◽  
Vol 17 (2) ◽  
pp. 907
Author(s):  
Rahmadwati Rahmadwati ◽  
Luthfiyah Rachmawati ◽  
Panca Mudjirahardjo ◽  
Eka Maulana
Keyword(s):  
Optical Sensors ◽  
Optical Sensor ◽  
Daucus Carota ◽  
Spin Coating ◽  
Deposition Method ◽  
Mercury Lamp ◽  
Current Output ◽  
Sensor Performance ◽  
Absorption Of Light ◽  
Light Absorbance

<span>This research designed optical sensors using mercury lamp of 160W. These sensors provided voltage and current output. The design of optical sensors used the organic based material,i.e. dye  carotene and phycocyanin. Fabrication of optical sensor in this research used spin coating deposition method. Based on the results of absorbance test, dye carotene had the largest absorption of light of 2.882 (a.u).  Dye phycocyanin at length had the largest absorption of light of 2.787 (a.u). Combination between dye carotene and phycocyanin, for a 3: 1 (Carotene: Phycocyanin) ratio had a waveform like a dye carotene with a peak of 2.587 (au), whereas for 1: 3 had a waveform like phycocyanin with a peak of 2,279 (au). But, sample 1: 1 ratio had decrement the light absorbance rate with peaks of 1.183 (au). At the voltage testing result, combination of phycocyanin: carotene (1:3) had the best linearity. The response time of dye 3:1 (phycocyanin: carotene), 1:1, 1:3, phycocyanin, and carotene were 6.72 s, 2.469s, 1.171s, 2.66s and 7.01s respectively. </span>

Continuous measurement of pollution due to urban effluents under wet conditions using optical systems

1995 ◽  
Vol 32 (1) ◽  
pp. 241-247
Author(s):  
Gwenael Ruban
Keyword(s):  
Optical Sensors ◽  
Optical Systems ◽  
Sample Collection ◽  
Rainfall Events ◽  
Automation Systems ◽  
Calibration Sample ◽  
Long Time ◽  
Pollution Measurement ◽  
Measurement Validation ◽  
Better Than

Optical sensors appear well adapted to the pollution measurement of urban discharges during wet weather: they allow a continuous and long time investigation of sudden and highly variable phenomena such as rainfall events. They may also be connected to remote monitoring and sanitary equipment automation systems. This paper deals with the measurement principles and use of this type of equipment: adjustment and calibration, sample collection, equipment maintenance and measurement validation. Taking into account the hydraulicity (flow rate or velocity) allows one to improve appreciably the calibration for runoff waters. Calibration at the laboratory seems better than calibration using registered data on the field, as it makes it possible to eliminate the Suspended Matter under-estimation resulting from sampling/analysis.

scholarly journals Determining Weight of Cargo Onboard Ship by Means of Optical Fibre Technology Draft Reading

2012 ◽  
Vol 23 (6) ◽  
pp. 421-429 ◽  
Author(s):  
Renato Ivče ◽  
Irena Jurdana ◽  
Robert Mohović
Keyword(s):  
Sea Level ◽  
Optical Fibre ◽  
Optical Sensors ◽  
Optical Sensor ◽  
Measuring Method ◽  
Liquid Level ◽  
Fibre Technology ◽  
Navigational System ◽  
Displacement Based ◽  
Made In

The accuracy of measuring mass of loaded or discharged cargo by draft survey mass measuring method varies due to both systematic and accidental errors. The paper analyzes an error of draft readings on the calculated quarter mean draft, displacement based on the calculated quarter mean draft and the final displacement. By analyzing this problem, the authors have reached the conclusion that the influence of an error made in draft readings can be significant, especially on the draft marks amidships. Optical fibre technology has been suggested as a new option for draft readings. In this paper, the authors propose a liquid level optical sensor for measuring the sea level in the sounding pipe. Draft readings obtained by optical sensors will be entered into ships’ navigational system and load master. KEY WORDS: ship’s draft, error of draft readings, optical fibre technology, liquid level optical sensors.

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