A highly selective and simple fluorescent sensor for mercury (II) ion detection based on cysteamine‐capped CdTe quantum dots synthesized by the reflux method

Ding, Xiaojie; Qu, Lingbo; Yang, Ran; Zhou, Yuchen; Li, Jianjun

doi:10.1002/bio.2761

Cited by 68 publications

(18 citation statements)

References 39 publications

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“…Energy levels of donor obtained from Brus's approximations, show a nice matching with acceptor's energy level (Scheme ). Similar quenching phenomena are reported in the literature but most of them studied hole or electron transfer from QD* to π‐conjugated polymers . For an instance, Ghosh and colleagues studied the hole transfer in CdTe QD‐MEHPPV hybrid system, where they observed excited state lifetime of CdTe QD quenched significantly in the presence of MEHPPV π‐conjugated polymer nanoparticles.…”

Section: Resultssupporting

confidence: 70%

Study of Interfacial Charge Transfer from an Electron Rich Organic Molecule to CdTe Quantum Dot by using Stern‐Volmer and Stochastic Kinetic Models

et al. 2020

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Photoinduced electron transfer (PET) from N‐methylaniline (NMA) to a photoexcited CdTe quantum dot (QD*) is studied in toluene. The PET mechanism at low to moderate quencher (NMA) concentrations (<0.08 M) remains mostly collisional with some contributions from QD‐NMA complex formation. However, at high quencher concentrations (>0.10 M), QDs form larger numbers of static complexes with NMA molecules leading to a steep positive deviation in the steady‐state Stern–Volmer curves. An isothermal titration calorimetry (ITC) study confirms the formation of QD‐NMA complexes (K∼150 M−1) at high quencher concentrations. Fitting our experimental data using a stochastic kinetic model indicates that the number of NMA molecules attached per QD at highest NMA concentration (∼0.16 M) used in this study decreases from ∼0.76 to ∼0.47 with reducing the QD size from ∼5.2 nm to ∼3.2 nm. However, the PET rate increases with decreasing QD size, which is commensurate with the observation that the chemical driving force (ΔG) increases with decreasing the QD particle size. We have analyzed the PET kinetics mainly by using Stern‐Volmer fittings. However, in some cases Tachiya's stochastic kinetic model is used for stoichiometric analysis, which seems to be useful only at high quencher concentrations. The measured PET rate coefficients in all the cases are found to be at least an order of magnitude lower when compared to the diffusion‐controlled rate of the reaction medium.

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Section: Resultssupporting

confidence: 70%

Study of Interfacial Charge Transfer from an Electron Rich Organic Molecule to CdTe Quantum Dot by using Stern‐Volmer and Stochastic Kinetic Models

et al. 2020

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“…Apart from photo voltaic applications, CdTe QDs being the best alternative to the molecular fluorophores, have appealed an intense interest of researchers working on various sensing, and bio‐application fields . In the last couple of decades, literatures have witnessed a burgeoning use of nanoscale semiconductors and its alloys in several occasions for the detection of various analytes in biology and chemistry . Efficiency of a fluorescence based sensing application depends on the extent of fluorescence quenching of the sensor molecule either by PET or FRET reaction .…”

Section: Introductionmentioning

confidence: 99%

“…[15] In the last couple of decades, literaturesh ave witnessed ab urgeoning use of nanoscale semiconductors and its alloys in several occasions for the detection of variousa nalytes in biology and chemistry. [16][17][18] Efficiency of af luorescenceb ased sensing application depends on the extent of fluorescence quenching of the sensorm olecule either by PET or FRET reaction. [19] CdTeQ De mits as a result of recombination of exciton.…”

Section: Introductionmentioning

confidence: 99%

Role of Emissive and Non‐Emissive Complex Formations in Photoinduced Electron Transfer Reaction of CdTe Quantum Dots

Bharadwaj

Choudhary

Hazra

et al. 2019

Chemistry An Asian Journal

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Bimolecular photoinduced electron transfer (PET) from excited state CdTe quantum dot (QD*) to an electron deficient molecule 2,4‐dinitrotoluene (DNT) is studied in toluene. We observed two types of QD‐DNT complex formations; (i) non‐emissive complex, in which DNT is embedded deep inside the surface polymer layer of QD and (ii) emissive complex, in which DNT molecules are attached to QDs but approach to the QD core is shielded by polymer layer. Because of its non‐emissive nature, the lifetime of QD is not affected by dark complex formation, though the steady‐state emission is greatly quenched. However, emissive complex formation causes both, lifetime and steady‐state emission quenching. In our fitting model, consideration of Poisson distribution of the attached quencher (DNT) molecules at QD surface enables a comprehensive fitting to our time resolved data. QD‐DNT complex formation was confirmed by an isothermal titration calorimetry (ITC) study. Fitting to the time resolved data using a stochastic kinetic model shows moderate increase (0.05 ns−1 to 0.072 ns−1) of intrinsic quenching rate with increasing the QD particle size (from ≈3.2 nm to ≈5.2 nm). Our fitting also reveals that the number of DNT molecules attached to a single QD increases from ≈0.1–0.2 to ≈1.2–1.7, as the DNT concentration is increased from ≈1 mm to 17.5 mm. Complex formation at higher quencher concentration assures that the observed PET kinetics is a thermodynamically controlled process where solvent diffusion has no role on it.

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“…5c). Finally, using the three-sigma method (3s/k), [66][67][68] the iron(III) detection limit for the PAF-1-ET and 8-hydroxyquinoline assay was determined to be 150 mg L À1 (see Fig. S17 and the ESI for details †).…”

Section: Iron Capture and Detection In Synthetic And Environmental Wamentioning

confidence: 99%

Iron Detection and Remediation with a Functionalized Porous Polymer Applied to Environmental Water Samples

Lee¹,

Uliana²,

Taylor³

et al. 2019

Preprint

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<div> <p>Iron is one of the most abundant elements in the environment and in the human body. As an essential nutrient, iron homeostasis is tightly regulated, and iron dysregulation is implicated in numerous pathologies, including neuro-degenerative diseases, atherosclerosis, and diabetes. Endogenous iron pool concentrations are directly linked to iron ion uptake from environmental sources such as drinking water, providing motivation for developing new technologies for assessing iron(II) and iron(III) levels in water. However, conventional methods for measuring aqueous iron pools remain laborious and costly and often require sophisticated equipment and/or additional processing steps to remove the iron ions from the original environmental source. We now report a simplified and accurate chemical platform for capturing and quantifying the iron present in aqueous samples through use of a post-synthetically modified porous aromatic framework (PAF). The ether/thioether-functionalized network polymer, PAF-1-ET, exhibits high selectivity for the uptake of iron(II) and iron(III) over other physiologically and environmentally relevant metal ions. Mössbauer spectroscopy, XANES, and EXAFS measurements provide evidence to support iron(III) coordination to oxygen-based ligands within the material. The polymer is further successfully employed to adsorb and remove iron ions from groundwater, including field sources in West Bengal, India. Combined with an 8-hydroxyquinoline colorimetric indicator, PAF-1-ET enables the simple and direct determination of the iron(II) and iron(III) ion concentrations in these samples, providing a starting point for the design and use of molecularly-functionalized porous materials for potential dual detection and remediation applications.</p></div>

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A highly selective and simple fluorescent sensor for mercury (II) ion detection based on cysteamine‐capped CdTe quantum dots synthesized by the reflux method

Cited by 68 publications

References 39 publications

Study of Interfacial Charge Transfer from an Electron Rich Organic Molecule to CdTe Quantum Dot by using Stern‐Volmer and Stochastic Kinetic Models

Study of Interfacial Charge Transfer from an Electron Rich Organic Molecule to CdTe Quantum Dot by using Stern‐Volmer and Stochastic Kinetic Models

Role of Emissive and Non‐Emissive Complex Formations in Photoinduced Electron Transfer Reaction of CdTe Quantum Dots

Iron Detection and Remediation with a Functionalized Porous Polymer Applied to Environmental Water Samples

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