Fluorescent carbon dots for the sensitive detection of Cr(<scp>vi</scp>) in aqueous media and their application in test papers

Bu, Lingli; Peng, Jingdong; Peng, Huanjun; Liu, Shaopu; Xiao, Huan; Liu, Dan; Pan, Ziyu; Yu, C. X.; Chen, Fang; He, Yan

doi:10.1039/c6ra19977a

Cited by 69 publications

(25 citation statements)

References 52 publications

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“…There are different methods to synthesize CDs, such as the electrochemical method, hydrothermal method, microwave synthesis technique, simple heating technique, etc. The hydrothermal method, or simple heating technique, is advantageous and is better than other techniques due to its simple preparation process and low energy consumption, and it enables easy control over reactions.…”

Section: Introductionmentioning

confidence: 99%

A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging

et al. 2019

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In this study, we have reported the synthesis of luminescent carbon dots (CDs) from indigenous potato sources by simple heating reactions. The as‐synthesized CDs exhibited an average size of ~ 5.97 nm with a quantum yield (QY) of 6.08%. Furthermore, the CDs possessed high water‐solubility, possibly due to the presence of ─COOH and ─OH groups on their surfaces. The quenching of luminescence of the CDs specifically by Cr6+ and Fe3+ ions was used to detect chromium and iron in the water sample. The minimum limit of detection (LOD) for Cr6+ and Fe3+ ions was found to be 0.012 μM and 0.000549 μM, respectively, in a linear range of 0.5 μM‐100 μM and 0.5 μM‐5 μM for Cr6+ and Fe3+, respectively, which was well below the concentration specified by WHO. We used our sensing system to detect the metal ions in water from the Brahmaputra River as well as in tannery water. In addition, the MTT‐based cell viability experiments showed that the CDs were nontoxic within 200 μg/mL. High quantum yield and the easy uptake of CDs enabled the quick labelling of cytoplasm of the HeLa cells, which can be further attributed to bioimaging applications.

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Section: Introductionmentioning

confidence: 99%

A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging

et al. 2019

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“…Desde a sua descoberta acidentalmente em 2004, durante uma purificação rotineira de nanotubos de carbono [1,2], os pontos quânticos de carbono, ou simplesmente carbon dots (C-Dots), vêm atraindo atenção de pesquisadores do mundo inteiro, por ser um novo tipo de nanomaterial de carbono, que exibe luminescência, biocompatibilidade, tamanhos inferiores a 10 nm, solubilidade em água e que podem ser obtidos por rotas sintéticas de baixo custo [3,4]. Em virtude das suas propriedades ópticas únicas, os C-Dots têm sido aplicados em diferentes áreas, a exemplo das biológicas, ambientais e ópticas-eletrônicas [3,5,6]. O mecanismo de luminescência dos C-Dots ainda não é totalmente elucidado, uma vez que são produzidos por diversos precursores e diferentes rotas sintéticas, além de pós-tratamentos, sendo assim, apresentam desempenhos ópticos diversos [4].…”

Section: Introductionunclassified

Resíduo de fruta cítrica como precursor de Carbon dots: um estudo de reprodutibilidade

et al. 2020

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Nos últimos anos, a busca por precursores verdes para a síntese de nanopartículas de carbono (carbon dots), tem despertado interesse da comunidade científica, devido dentre outros aspectos, o alinhamento com a química verde, abundância de resíduos carbonáceos e ampla faixa de aplicações desses nanomateriais. Nesse sentido, uma estratégia simples, verde e de baixo custo, foi desenvolvida para a síntese reprodutível de carbon dots (C-dots) usando extrato do bagaço de limão, proveniente de diferentes cidades de Alagoas, Brasil, a saber Rio Largo, Coruripe e Maceió. As dispersões aquosas das nanopartículas, exibiram emissão no verde, tamanhos médios abaixo de 10 nm e índice de polidispersividade entre 0-1, indicando uma distribuição monodispersa das nanopartículas. As análises de FTIR e absorção UV-Vis evidenciaram a presença de estiramentos vibracionais de grupos funcionais oxigenados e bandas de absorção atribuídas as transições π - π* (230 nm) e n - π* em (286 nm), respectivamente. Os espectros de fotoluminescência, mostraram que a emissão dos C-dots é dependente do comprimento de onda de excitação, exibindo uma intensidade máxima em 445 nm, quando excitados em 350 nm. Assim, foi observada uma boa correlação das propriedades ópticas e estruturais dos C-dots, indicando a reprodutibilidade dessas nanopartículas. Além disso, os C-Dots exibiram potencial aplicação como sensor de cromo (VI), demonstrando que o uso do extrato do bagaço de limão é uma forma eficiente de produzir C-dots de baixo custo via química verde.

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“…To synthesize CDs from different bio resources, different methods have also been employed. For example, electrochemical method, 16 hydrothermal method, 11 microwave synthesis technique, [17][18][19] simple heating technique 20 etc. are some of the different CD synthesis techniques.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the oxygengasand UVbarrier properties of nano ZnO coated PET and PHBHHx packaging films via ultrasonic spray coating

Abbas¹

2019

Nanotech France 2019 Conference Proceedings

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The acoustoelectric effect is the generation of a acoustoelectric current in a non-biased device by a piezoactive acoustic wave. This effect has recently attracted the attention of researchers as possible method to control the motion of massive objects in the quantum regime. We suggest use this effect for development of high sensitive nanoelectronic sensors. The sensitivity could be increase through the use of modulation mode of operation based on the acoustic pilot signal and the transition from quasi-stationary measurement to measurement at the modulation frequency. The acoustic delay line based on shear-horizontal acoustic wave of zero order (SH 0 ) with resonant frequency 2.77 MHz in Y-X LiNbO 3 plate was produced. The nanostructure consisting of nanowire with size 20nm x 180nm was placed in the center between IDTs. The volt-ampere characteristics of this nanowire in presence and at the absence of the acoustic wave were meazured by picoampermeter. The analysis has shown that presence of piezoactive acoustic wave is influenced on electric current in a nanowire.Keywords: acoustoelectric effect, nanowire, volt-ampere characteristics, shear-horizontal acoustic wave, lithium niobate plate, sensor applications Experimental Fabrication of the Acoustic Delay LineThe acoustic delay line and the system of electrodes supplied to the nanostructure were produced as follows. First, the lithium niobate substrate was washed in a centrifuge with a stream of isopropyl alcohol and acetone, and then wiped with dimethylformamide. Then, a Shipley S1813 resist was applied by the centrifuge, after that it was dried for 5 minutes on HotPlate at a temperature of 115 0 C. The corresponding photomask was superimposed on the sample in the MA-750 combining unit and the structure was exposed to UV radiation at a wavelength of 400 nm for 75 seconds at an intensity of 50 mW /cm 2 . Next, the sample was placed for 1 minute in a KOH-based developer with a concentration of 0.01 mg/ml. After that, thermal evaporation of 100 nm of titanium and 30 nm of gold on top of it was sputtered through the obtained photoresist mask. Then, using the lift-off method, the sample was freed from the remnants of the undeveloped photoresist, and the result was a structure of IDT and supply electrodes for the nanostructure. The geometry size of obtained delay line was 11mm x 13mm with substrate thickness 0.35mm. Fabrication of the Central NanostructureAfter production of the delay line, the corresponding nanostructure was placed between the IDT. To produce it, we used an electron lithography method with a two-layer overhanging resistive mask. This approach allows to avoid low-quality edges due to the contact of the sprayed metal with the walls of the photoresist and to obtain rather sharp boundaries of metal nanostructures [6]. In result of modified method we obtained central nanostructure with geometry size 80x80 m 2 .This structure consisted of eight nanowires. Each nanowire was 180nm in length, 20nm in width and with thickness about 77nm (chromium -7nm, gold-50...

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Fluorescent carbon dots for the sensitive detection of Cr(vi) in aqueous media and their application in test papers

Abstract: A fluorescent sensor for the sensitive and selective detection of Cr(vi) was developed and applied to spot test papers.

Cited by 69 publications

References 52 publications

A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging

A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging

Resíduo de fruta cítrica como precursor de Carbon dots: um estudo de reprodutibilidade

Comparison of the oxygengasand UVbarrier properties of nano ZnO coated PET and PHBHHx packaging films via ultrasonic spray coating

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