Graphene quantum dots as a nanoprobe for analysis of o- and p-nitrophenols in environmental water adopting conventional fluorometry and smartphone image processing-assisted paper-based analytical device. In-depth study of sensing mechanisms

El-Shaheny, Rania; Yoshida, Sakura; Fuchigami, Takeshi

doi:10.1016/j.microc.2020.105241

Cited by 42 publications

(21 citation statements)

References 35 publications

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“…1,2 The agriculture sector introduces pnitrophenols (PNPs) to the soil and drinkable water system through extensive use of organophosphorus pesticides which on hydrolysis convert into PNP. 3,4 Additionally, these PNPs owing to their persistent toxic and mutagenic nature are generally too secure to be separate from soil and water by selfdecomposition and hence possess a great threat to aquatic and human life. 1,5,6 The U.S. Environmental Protection Agency (EPA) has catalogued the PNP as the major pollutant with maximum permissible limits in the commercial sewerage as 1− 20 mg L −1 .…”

Section: Introductionmentioning

confidence: 99%

Ecofriendly Green Synthesis of the ZnO-Doped CuO@Alg Bionanocomposite for Efficient Oxidative Degradation of p-Nitrophenol

et al. 2020

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In the present study, ecofriendly green synthesized ZnO/CuO nanorods were prepared by using the stabilizing and reducing characteristics of the alginate biopolymer. The bionanocomposite (BNC) material was characterized by various sophisticated analytical tools such as Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy− energy dispersive X-ray spectroscopy, transmission electron microscopy, UV−visible spectroscopy, differential scanning calorimetry, and the Brunauer−Emmett−Teller (BET) method. The composition of ZnO/CuO@Alg BNC was found to be C (16.16 ± 0.42%), O (42.26 ± 1.87%), Cu (31.96 ± 1.05%), and Zn (9.62 ± 0.48%), which also supports the approximate 3:1 ratio of Cu 2+ and Zn 2+ taken as the precursor. The nanocrystalline spinel ferrite was found to have a BET specific surface area of 19.24 m 2 g −1 with a total pore volume of 0.075 cm 3 g −1 and 1.45 eV as the band gap energy (E g ). Further, the material was applied for the photodegradation of p-nitrophenol (PNP) under the advanced oxidative process (AOP) under visible sunlight irradiation. The visible light radiation was used for the degradation of PNP under pH 2 conditions and resulted in 98.38% of the photocatalytic efficiency of the ZnO/CuO@Alg catalyst within 137 min of irradiation time. The photocatalytic reaction was best defined by the pseudo-first-order kinetics which involves the adsorption of the PNP molecule on the surface of the catalyst, thereby demineralizing it in the presence of advanced active • OH radicals. The values of rate constant for the pseudo-first-order model (k 1 ) were calculated as 0.013, 0.016, 0.019, 0.021, and 0.023 min −1 with half-life periods of 53.31, 43.31, 36.47, 33.00, and 30.13 min for 10−50 mg L −1 PNP concentrations. The presence of t-butyl alcohol decreases the photocatalytic efficiency, which suggests that the degradation of PNP was accomplished by the • OH oxidative radical.

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Section: Introductionmentioning

confidence: 99%

Ecofriendly Green Synthesis of the ZnO-Doped CuO@Alg Bionanocomposite for Efficient Oxidative Degradation of p-Nitrophenol

et al. 2020

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“…The plot between %E of both observed and corrected fluorescence intensities of N,S‐CQDs and CRO concentration in moles indicated that the mechanism of quenching during this study was IFE (Figure 6), which was attributed to the amidation reaction between the –COOH groups of CRO and some of –NH 2 groups of the as‐prepared N,S‐CQDs. [ 43 ] In addition, hydrogen bonding between surface groups of the prepared dots (–OH, –NH 2 , and –COOH) and CRO and π–π stacking between heterocyclic part of dots and phenyl group of CRO occurred.…”

Section: Resultsmentioning

confidence: 99%

Utilization of N,S‐doped carbon dots as a fluorescent nanosensor for determination of cromolyn based on inner filter effect: application to aqueous humour

et al. 2022

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A simple and eco-friendly hydrothermal technique is used to prepare water soluble N-and S-co-doped carbon quantum dots probes (N,S-CQDs) from thiosemicarbazide and citric acid. Several characterization techniques were performed to ensure the successful synthesis of highly luminescent N,S-CQDs. The prepared probe exhibited analytical potential as an optical nanosensor for the spectrofluorimetric determination of cromolyn sodium (CRO) in its pharmaceutical dosage forms and aqueous humour. The emission intensity of the synthesized N,S-CQDs was measured at 411 nm after excitation at 345 nm. Addition of increasing concentrations of CRO to N,S-CQDs led to quenching of its fluorescence intensity. CRO was investigated within a wide concentration range 10.0-150.0 μM with a limit of detection of 2.0 μM and a limit of quantification of 6.0 μM. The quenching of fluorescent N,S-CQDs occurred through the inner filter effect (IFE). The developed spectrofluorimetric method was successfully optimized and validated according to the International Council of Harmonisation guidelines (ICH). The method greenness is proved through using both Eco-Scale and AGREE approaches.

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“…4 a). In 2020 [ 166 ], taking advantage of the blue luminescence of graphene quantum dots (GQDs), o- and p-nitrophenols (ONP and PNP, respectively), two kinds of endocrine disruptors were determined selectively and sensitively. The quantitative analysis of ONP and PNP showed linear ranges of 0.30–60.0 µg/mL and 0.20–40.0 µg/mL, respectively, with LODs of 0.07 µg/mL for ONP and 0.03 µg/mL for PNP.…”

Section: Optical Detection Methodsmentioning

confidence: 99%

“…In the field of environmental monitoring, FL was applied on detection of metal ions [155][156][157][158][159][160][161][162], anion [163][164][165], gas [155], and organic compounds [166][167][168]. Liu [155] has reported a FL probe on μPads with carbazole for the detection of Cu 2+ and gaseous H 2 S. In 2019, a paper-based platform was established [157] using a hand-held UV lamp as an excitation resource.…”

Section: Environmental Monitoringmentioning

confidence: 99%

Recent Advances and Applications in Paper-Based Devices for Point-of-Care Testing

Hou

Guo

et al. 2022

J. Anal. Test.

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Point-of-care testing (POCT), as a portable and user-friendly technology, can obtain accurate test results immediately at the sampling point. Nowadays, microfluidic paper-based analysis devices (μPads) have attracted the eye of the public and accelerated the development of POCT. A variety of detection methods are combined with μPads to realize precise, rapid and sensitive POCT. This article mainly introduced the development of electrochemistry and optical detection methods on μPads for POCT and their applications on disease analysis, environmental monitoring and food control in the past 5 years. Finally, the challenges and future development prospects of μPads for POCT were discussed.

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Graphene quantum dots as a nanoprobe for analysis of o- and p-nitrophenols in environmental water adopting conventional fluorometry and smartphone image processing-assisted paper-based analytical device. In-depth study of sensing mechanisms

Cited by 42 publications

References 35 publications

Ecofriendly Green Synthesis of the ZnO-Doped CuO@Alg Bionanocomposite for Efficient Oxidative Degradation of p-Nitrophenol

Ecofriendly Green Synthesis of the ZnO-Doped CuO@Alg Bionanocomposite for Efficient Oxidative Degradation of p-Nitrophenol

Utilization of N,S‐doped carbon dots as a fluorescent nanosensor for determination of cromolyn based on inner filter effect: application to aqueous humour

Recent Advances and Applications in Paper-Based Devices for Point-of-Care Testing

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