An optical ratiometric temperature sensor based on dopant-dependent thermal equilibrium in dual-emitting Ag&Mn:ZnInS quantum dots

RSC Advances ◽  
2016 ◽  
Vol 6 (63) ◽  
pp. 58113-58117 ◽  
Author(s):  
Guangguang Huang ◽  
Chunlei Wang ◽  
Xiaojing Xu ◽  
Yiping Cui
Keyword(s):  
Quantum Dots ◽  
Optical Sensor ◽  
Temperature Sensor ◽  
Thermal Equilibrium ◽  
Temperature Detection ◽  
Pl Intensity

A novel optical sensor for ratiometric temperature detection is devised via Ag&Mn:ZnInS quantum dots (QDs). The temperature can be read via the PL ratios of Ag-related and Mn-related PL intensity.

Carbon quantum dots for optical sensor applications: A review

2021 ◽  
Vol 139 ◽  
pp. 106928
Author(s):  
Nur Afifah Ahmad Nazri ◽  
Nur Hidayah Azeman ◽  
Yunhan Luo ◽  
Ahmad Ashrif A Bakar
Keyword(s):  
Quantum Dots ◽  
Optical Sensor ◽  
Carbon Quantum Dots ◽  
Sensor Applications

scholarly journals Photoluminescence of CdSe/ZnS quantum dots in nematic liquid crystals in electric fields

2018 ◽  
Vol 9 ◽  
pp. 1544-1549 ◽  
Author(s):  
Margarita A Kurochkina ◽  
Elena A Konshina ◽  
Daria Khmelevskaia
Keyword(s):  
Quantum Dots ◽  
Liquid Crystals ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Fields ◽  
Dielectric Anisotropy ◽  
Vertical Position ◽  
Decay Times ◽  
Pl Intensity

We have experimentally investigated the effect of the reorientation of a nematic liquid crystal (LC) in an electric field on the photoluminescence (PL) of CdSe/ZnS semiconductor quantum dots (QDs). To the LC with positive dielectric anisotropy, 1 wt % QDs with a core diameter of 5 nm was added. We compared the change of PL intensity and decay times of QDs in LC cells with initially planar or vertically orientated molecules, i.e., in active or passive LC matrices. The PL intensity of the QDs increases four-fold in the active LC matrix and only 1.6-fold in the passive LC matrix without reorientation of the LC molecules. With increasing electric field strength, the quenching of QDs luminescence occurred in the active LC matrix, while the PL intensity did not change in the passive LC matrix. The change in the decay time with increasing electric field strength was similar to the behavior of the PL intensity. The observed buildup in the QDs luminescence can be associated with the transfer of energy from LC molecules to QDs. In a confocal microscope, we observed the increase of particle size and the redistribution of particles in the active LC matrix with the change of the electric field strength. At the same time, no significant changes occurred in the passive LC matrix. With the reorientation of LC molecules from the planar in vertical position in the LC active matrix, quenching of QD luminescence and an increase of the ion current took place simultaneously. The obtained results are interesting for controlling the PL intensity of semiconductor QDs in liquid crystals by the application of electric fields.

Graphene quantum dots prepared from glucose as optical sensor for glucose

2017 ◽  
Vol 184 ◽  
pp. 110-116 ◽  
Author(s):  
Mona Shehab ◽  
Shaker Ebrahim ◽  
Moataz Soliman
Keyword(s):  
Quantum Dots ◽  
Optical Sensor ◽  
Graphene Quantum Dots

scholarly journals An optical sensor for selective detection of phenol via double cross-linker precipitation polymerization

RSC Advances ◽  
2020 ◽  
Vol 10 (42) ◽  
pp. 25402-25407
Author(s):  
Xiaodong Lv ◽  
Peng Gao
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Optical Sensor ◽  
Precipitation Polymerization ◽  
Transfer Mechanism ◽  
Selective Detection ◽  
Electron Transfer Mechanism ◽  
Cross Linker ◽  
Double Cross

Based on the electron-transfer mechanism between the template and quantum dots (QDs), an optical sensor was structured.

scholarly journals An ultrafast quantum thermometer from graphene quantum dots

2019 ◽  
Vol 1 (5) ◽  
pp. 1772-1783 ◽  
Author(s):  
Poonam Sehrawat ◽  
Abid Abid ◽  
S. S. Islam
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Temperature Sensor ◽  
Graphene Quantum Dots ◽  
Reduced Graphene

We report an ultra-sensitive temperature sensor derived from graphene quantum dots (GQDs) embedded in a self-standing reduced graphene oxide (RGO) film.

Optical Detection of the Pesticide by Functionalized Quantum Dots as Fluorescence-Based Biosensor

2011 ◽  
Vol 495 ◽  
pp. 314-318 ◽  
Author(s):  
Nguyen Ngoc Hai ◽  
Vu Duc Chinh ◽  
Tran Kim Chi ◽  
Ung Thi Dieu Thuy ◽  
Nguyen Xuan Nghia ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Detection ◽  
Thick Shell ◽  
Study Results ◽  
Pl Intensity ◽  
Best Fit

In this work, the results on using biosensor composed from quantum dots as transducer and acetylcholinesterase enzymes (AChE) to detect pesticides optically are presented. The used quantum dots were CdTe, CdSe/ZnS 10 monolayer (ML) and CdSe/ZnSe2ML/ZnS 8 ML – the brand new thick-shell quantum dots (QD). The study results pointed out that the CdSe/ZnS 10 ML and CdSe/ZnSe 2ML/ZnS 8ML quantum dots best fit for the role of transducers in biosensors. In the biosensor, acetylthiocholine (ATCh) is used as indicator for the AChE enzymes to work, since it is a very powerful hydrolyte with the presence of AChE enzymes. Moreover, the organophosphorus (OP) pesticides are the inhibitors for the AChE enzymes, thus, by the biosensors that we designed, we can detect pesticides by the change in photoluminescence (PL) intensity of QDs, with the detection of OP like parathion methyl is 0.05 ppm, and acetamiprid is 2.5 ppm.

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