Special Issue "Functional Nanostructures for Sensors, Optoelectronic Devices and Drug Delivery"

A special issue of Nanomaterials (ISSN 2079-4991).

Deadline for manuscript submissions: closed (30 September 2019).

Special Issue Editor

Dr. Maria Angela Castriciano
E-Mail Website
Guest Editor
CNR-ISMN, Istituto Per Lo Studio Dei Materiali Nanostrutturati, c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Italy
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Nanoparticles and nanostructured materials, due to their tunable physicochemical properties and their enhanced performance with respect to the corresponding bulk counterparts, represent an active area of research for their impact in many application fields. Recent progress in the synthesis of nanomaterials and the fundamental understanding of their properties has led to significant advances in nanomaterial-based sensors, in optoelectronic devices, and in drug delivery systems.

For these applications, it is essential to design and synthesize novel systems with an optimized structure and properties, a goal which has been achieved using nonconventional approaches. In this respect, nanostructured materials with peculiar optical properties are attracting increasing interest since their optical response, in terms of electronic absorption, emission fluorescence, optical activity, photocurrent, and so on, can be largely influenced by slight changes in the microenvironments and in the presence of specific analytes. These peculiar features can be conveniently exploited in a variety of different applications.

This Special Issue welcomes the submission of original research papers or comprehensive reviews that demonstrate or summarize significant advances in the synthesis and application of novel functional nanostructures, with potential applications in sensor, optoelectronic devices, and/or drug delivery.

Dr. Maria Angela Castriciano
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • nanomaterials
  • aggregation phenomena
  • supramolecular chemistry
  • chromophoric systems
  • metal nanoparticles
  • quantum dots

Published Papers (13 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Polyfluorene-Based Multicolor Fluorescent Nanoparticles Activated by Temperature for Bioimaging and Drug Delivery
Nanomaterials 2019, 9(10), 1485; https://doi.org/10.3390/nano9101485 (registering DOI) - 18 Oct 2019
Abstract
Multifunctional nanoparticles have been attracting growing attention in recent years because of their capability to integrate materials with different features in one entity, which leads them to be considered as the next generation of nanomedicine. In this work, we have taken advantage of [...] Read more.
Multifunctional nanoparticles have been attracting growing attention in recent years because of their capability to integrate materials with different features in one entity, which leads them to be considered as the next generation of nanomedicine. In this work, we have taken advantage of the interesting properties of conjugated polyelectrolytes to develop multicolor fluorescent nanoparticles with integrating imaging and therapeutic functionalities. With this end, thermosensitive liposomes were coated with three recently synthesized polyfluorenes: copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(phenylene)) bromide (HTMA-PFP), copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-4,7-(2- (phenyl)benzo(d) (1,2,3) triazole)) bromide (HTMA-PFBT) and copoly-((9,9-bis(6′-N,N,N- trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(naphtho(2,3c)-1,2,5-thiadiazole)) bromide (HTMA-PFNT), in order to obtain blue, green and red fluorescent drug carriers, respectively. The stability, size and morphology of the nanoparticles, as well as their thermotropic behavior and photophysical properties, have been characterized by Dynamic Light Scattering (DLS), Zeta Potential, transmission electron microscope (TEM) analysis and fluorescence spectroscopy. In addition, the suitability of the nanostructures to carry and release their contents when triggered by hyperthermia has been explored by using carboxyfluorescein as a hydrophilic drug model. Finally, preliminary experiments with mammalian cells demonstrate the capability of the nanoparticles to mark and visualize cells with different colors, evidencing their potential use for imaging and therapeutic applications. Full article
Show Figures

Figure 1

Open AccessArticle
Enhancing the Relative Sensitivity of V5+, V4+ and V3+ Based Luminescent Thermometer by the Optimization of the Stoichiometry of Y3Al5−xGaxO12 Nanocrystals
Nanomaterials 2019, 9(10), 1375; https://doi.org/10.3390/nano9101375 - 25 Sep 2019
Abstract
In this work the influence of the Ga3+ concentration on the luminescent properties and the abilities of the Y3Al5−xGaxO12: V nanocrystals to noncontact temperature sensing were investigated. It was shown that the increase of [...] Read more.
In this work the influence of the Ga3+ concentration on the luminescent properties and the abilities of the Y3Al5−xGaxO12: V nanocrystals to noncontact temperature sensing were investigated. It was shown that the increase of the Ga3+ amount enables enhancement of V4+ emission intensity in respect to the V3+ and V5+ and thus modify the color of emission. The introduction of Ga3+ ions provides the appearance of the crystallographic sites, suitable for V4+ occupation. Consequently, the increase of V4+ amount facilitates V5+ → V4+ interionic energy transfer throughout the shortening of the distance between interacting ions. The opposite thermal dependence of V4+ and V5+ emission intensities enables to create the bandshape luminescent thermometr of the highest relative sensitivity of V-based luminescent thermometers reported up to date (Smax, 2.64%/°C, for Y3Al2Ga3O12 at 0 °C). An approach of tuning the performance of Y3Al5−xGaxO12: V nanocrystals to luminescent temperature sensing, including the spectral response, maximal relative sensitivity and usable temperature range, by the Ga3+ doping was presented and discussed. Full article
Show Figures

Figure 1

Open AccessArticle
Two-Step Exfoliation of WS2 for NO2, H2 and Humidity Sensing Applications
Nanomaterials 2019, 9(10), 1363; https://doi.org/10.3390/nano9101363 - 24 Sep 2019
Abstract
WS2 exfoliated by a combined ball milling and sonication technique to produce few-layer WS2 is characterized and assembled as chemo-resistive NO2, H2 and humidity sensors. Microstructural analyses reveal flakes with average dimensions of 110 nm, “aspect ratio” of [...] Read more.
WS2 exfoliated by a combined ball milling and sonication technique to produce few-layer WS2 is characterized and assembled as chemo-resistive NO2, H2 and humidity sensors. Microstructural analyses reveal flakes with average dimensions of 110 nm, “aspect ratio” of lateral dimension to the thickness of 27. Due to spontaneous oxidation of exfoliated WS2 to amorphous WO3, films have been pre-annealed at 180 °C to stabilize WO3 content at ≈58%, as determined by X-ray Photoelectron Spectroscopy (XPS), Raman and grazing incidence X-ray Diffraction (XRD) techniques. Microstructural analysis repeated after one-year conditioning highlighted that amorphous WO3 concentration is stable, attesting the validity of the pre-annealing procedure. WS2 films were NO2, H2 and humidity tested at 150 °C operating Temperature (OT), exhibiting experimental detection limits of 200 ppb and 5 ppm to NO2 and H2 in dry air, respectively. Long-term stability of the electrical response recorded over one year of sustained conditions at 150 °C OT and different gases demonstrated good reproducibility of the electrical signal. The role played by WO3 and WS2 upon gas response has been addressed and a likely reaction gas-mechanism presented. Controlling the microstructure and surface oxidation of exfoliated Transition Metal Dichalcogenides (TMDs) represents a stepping-stone to assess the reproducibility and long-term response of TMDs monolayers in gas sensing applications. Full article
Show Figures

Graphical abstract

Open AccessArticle
SnSe2 Quantum Dots: Facile Fabrication and Application in Highly Responsive UV-Detectors
Nanomaterials 2019, 9(9), 1324; https://doi.org/10.3390/nano9091324 - 15 Sep 2019
Abstract
Synthesizing quantum dots (QDs) using simple methods and utilizing them in optoelectronic devices are active areas of research. In this paper, we fabricated SnSe2 QDs via sonication and a laser ablation process. Deionized water was used as a solvent, and there were [...] Read more.
Synthesizing quantum dots (QDs) using simple methods and utilizing them in optoelectronic devices are active areas of research. In this paper, we fabricated SnSe2 QDs via sonication and a laser ablation process. Deionized water was used as a solvent, and there were no organic chemicals introduced in the process. It was a facile and environmentally-friendly method. We demonstrated an ultraviolet (UV)-detector based on monolayer graphene and SnSe2 QDs. The photoresponsivity of the detector was up to 7.5 × 106 mAW−1, and the photoresponse time was ~0.31 s. The n–n heterostructures between monolayer graphene and SnSe2 QDs improved the light absorption and the transportation of photocarriers, which could greatly increase the photoresponsivity of the device. Full article
Show Figures

Figure 1

Open AccessFeature PaperArticle
Nanohybrid Assemblies of Porphyrin and Au10 Cluster Nanoparticles
Nanomaterials 2019, 9(7), 1026; https://doi.org/10.3390/nano9071026 - 18 Jul 2019
Abstract
The interaction between gold sub-nanometer clusters composed of ten atoms (Au10) and tetrakis(4-sulfonatophenyl)porphyrin (TPPS) was investigated through various spectroscopic techniques. Under mild acidic conditions, the formation, in aqueous solutions, of nanohybrid assemblies of porphyrin J-aggregates and Au10 cluster nanoparticles was [...] Read more.
The interaction between gold sub-nanometer clusters composed of ten atoms (Au10) and tetrakis(4-sulfonatophenyl)porphyrin (TPPS) was investigated through various spectroscopic techniques. Under mild acidic conditions, the formation, in aqueous solutions, of nanohybrid assemblies of porphyrin J-aggregates and Au10 cluster nanoparticles was observed. This supramolecular system tends to spontaneously cover glass substrates with a co-deposit of gold nanoclusters and porphyrin nanoaggregates, which exhibit circular dichroism (CD) spectra reflecting the enantiomorphism of histidine used as capping and reducing agent. The morphology of nanohybrid assemblies onto a glass surface was revealed by atomic force microscopy (AFM), and showed the concomitant presence of gold nanoparticles with an average size of 130 nm and porphyrin J-aggregates with lengths spanning from 100 to 1000 nm. Surface-enhanced Raman scattering (SERS) was observed for the nanohybrid assemblies. Full article
Show Figures

Graphical abstract

Open AccessArticle
Effective Modulation of Optical and Photoelectrical Properties of SnS2 Hexagonal Nanoflakes via Zn Incorporation
Nanomaterials 2019, 9(7), 924; https://doi.org/10.3390/nano9070924 - 27 Jun 2019
Abstract
Tin sulfides are promising materials in the fields of photoelectronics and photovoltaics because of their appropriate energy bands. However, doping in SnS2 can improve the stability and robustness of this material in potential applications. Herein, we report the synthesis of SnS2 [...] Read more.
Tin sulfides are promising materials in the fields of photoelectronics and photovoltaics because of their appropriate energy bands. However, doping in SnS2 can improve the stability and robustness of this material in potential applications. Herein, we report the synthesis of SnS2 nanoflakes with Zn doping via simple hydrothermal route. The effect of doping Zn was found to display a huge influence in the structural and crystalline order of as synthesized SnS2. Their optical properties attest Zn doping of SnS2 results in reduction of the band gap which benefits strong visible-light absorption. Significantly, enhanced photoresponse was observed with respect to pristine SnS2. Such enhancement could result in improved electronic conductivity and sensitivity due to Zn doping at appropriate concentration. These excellent performances show that Sn1−xZnxS2 nanoflakes could offer huge potential for nanoelectronics and optoelectronics device applications. Full article
Show Figures

Figure 1

Open AccessArticle
Morphology–Dependent Electrochemical Sensing Properties of Iron Oxide–Graphene Oxide Nanohybrids for Dopamine and Uric Acid
Nanomaterials 2019, 9(6), 835; https://doi.org/10.3390/nano9060835 - 01 Jun 2019
Cited by 3
Abstract
Various morphologies of iron oxide nanoparticles (Fe2O3 NPs), including cubic, thorhombic and discal shapes were synthesized by a facile meta-ion mediated hydrothermal route. To further improve the electrochemical sensing properties, discal Fe2O3 NPs with the highest electrocatalytic [...] Read more.
Various morphologies of iron oxide nanoparticles (Fe2O3 NPs), including cubic, thorhombic and discal shapes were synthesized by a facile meta-ion mediated hydrothermal route. To further improve the electrochemical sensing properties, discal Fe2O3 NPs with the highest electrocatalytic activity were coupled with graphene oxide (GO) nanosheets. The surface morphology, microstructures and electrochemical properties of the obtained Fe2O3 NPs and Fe2O3/GO nanohybrids were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. As expected, the electrochemical performances were found to be highly related to morphology. The discal Fe2O3 NPs coupled with GO showed remarkable electrocatalytic activity toward the oxidation of dopamine (DA) and uric acid (UA), due to their excellent synergistic effect. The electrochemical responses of both DA and UA were linear to their concentrations in the ranges of 0.02–10 μM and 10–100 μM, with very low limits of detection (LOD) of 3.2 nM and 2.5 nM for DA and UA, respectively. Moreover, the d-Fe2O3/GO nanohybrids showed good selectivity and reproducibility. The proposed d-Fe2O3/GO/GCE realized the simultaneous detection of DA and UA in human serum and urine samples with satisfactory recoveries. Full article
Show Figures

Graphical abstract

Open AccessArticle
“Three-Bullets” Loaded Mesoporous Silica Nanoparticles for Combined Photo/Chemotherapy
Nanomaterials 2019, 9(6), 823; https://doi.org/10.3390/nano9060823 - 31 May 2019
Abstract
This contribution reports the design, preparation, photophysical and photochemical characterization, as well as a preliminary biological evaluation of mesoporous silica nanoparticles (MSNs) covalently integrating a nitric oxide (NO) photodonor (NOPD) and a singlet oxygen (1O2) photosensitizer (PS) and encapsulating [...] Read more.
This contribution reports the design, preparation, photophysical and photochemical characterization, as well as a preliminary biological evaluation of mesoporous silica nanoparticles (MSNs) covalently integrating a nitric oxide (NO) photodonor (NOPD) and a singlet oxygen (1O2) photosensitizer (PS) and encapsulating the anticancer doxorubicin (DOX) in a noncovalent fashion. These MSNs bind the NOPD mainly in their inner part and the PS in their outer part in order to judiciously exploit the different diffusion radius of the cytotoxic NO and 1O2. Furthermore this silica nanoconstruct has been devised in such a way to permit the selective excitation of the NOPD and the PS with light sources of different energy in the visible window. We demonstrate that the individual photochemical performances of the photoactive components of the MSNs are not mutually affected, and remain unaltered even in the presence of DOX. As a result, the complete nanoconstruct is able to deliver NO and 1O2 under blue and green light, respectively, and to release DOX under physiological conditions. Preliminary biological results performed using A375 cancer cells show a good tolerability of the functionalized MSNs in the dark and a potentiated activity of DOX upon irradiation, due to the effect of the NO photoreleased. Full article
Show Figures

Figure 1

Open AccessArticle
Orange/Red Photoluminescence Enhancement Upon SF6 Plasma Treatment of Vertically Aligned ZnO Nanorods
Nanomaterials 2019, 9(5), 794; https://doi.org/10.3390/nano9050794 - 23 May 2019
Abstract
Although the origin and possible mechanisms for green and yellow emission from different zinc oxide (ZnO) forms have been extensively investigated, the same for red/orange PL emission from ZnO nanorods (nR) remains largely unaddressed. In this work, vertically aligned zinc oxide nanorods arrays [...] Read more.
Although the origin and possible mechanisms for green and yellow emission from different zinc oxide (ZnO) forms have been extensively investigated, the same for red/orange PL emission from ZnO nanorods (nR) remains largely unaddressed. In this work, vertically aligned zinc oxide nanorods arrays (ZnO nR) were produced using hydrothermal process followed by plasma treatment in argon/sulfur hexafluoride (Ar/SF6) gas mixture for different time. The annealed samples were highly crystalline with ~45 nm crystallite size, (002) preferred orientation, and a relatively low strain value of 1.45 × 10−3, as determined from X-ray diffraction pattern. As compared to as-deposited ZnO nR, the plasma treatment under certain conditions demonstrated enhancement in the room temperature photoluminescence (PL) emission intensity, in the visible orange/red spectral regime, by a factor of 2. The PL intensity enhancement induced by SF6 plasma treatment may be attributed to surface chemistry modification as confirmed by X-ray photoelectron spectroscopy (XPS) studies. Several factors including presence of hydroxyl group on the ZnO surface, increased oxygen level in the ZnO lattice (OL), generation of F–OH and F–Zn bonds and passivation of surface states and bulk defects are considered to be active towards red/orange emission in the PL spectrum. The PL spectra were deconvoluted into component Gaussian sub-peaks representing transitions from conduction-band minimum (CBM) to oxygen interstitials (Oi) and CBM to oxygen vacancies (VO) with corresponding photon energies of 2.21 and 1.90 eV, respectively. The optimum plasma treatment route for ZnO nanostructures with resulting enhancement in the PL emission offers strong potential for photonic applications such as visible wavelength phosphors. Full article
Show Figures

Figure 1

Open AccessArticle
Improvement of Ethanol Gas-Sensing Responses of ZnO–WO3 Composite Nanorods through Annealing Induced Local Phase Transformation
Nanomaterials 2019, 9(5), 669; https://doi.org/10.3390/nano9050669 - 30 Apr 2019
Cited by 3
Abstract
In this study, ZnO–WO3 composite nanorods were synthesized through a combination of hydrothermal growth and sputtering method. The structural analysis results revealed that the as-synthesized composite nanorods had a homogeneous coverage of WO3 crystallite layer. Moreover, the ZnO–WO3 composite nanorods [...] Read more.
In this study, ZnO–WO3 composite nanorods were synthesized through a combination of hydrothermal growth and sputtering method. The structural analysis results revealed that the as-synthesized composite nanorods had a homogeneous coverage of WO3 crystallite layer. Moreover, the ZnO–WO3 composite nanorods were in a good crystallinity. Further post-annealed the composite nanorods in a hydrogen-containing atmosphere at 400 °C induced the local phase transformation between the ZnO and WO3. The ZnO–WO3 composite nanorods after annealing engendered the coexistence of ZnWO4 and WO3 phase in the shell layer which increased the potential barrier number at the interfacial contact region with ZnO. This further enhanced the ethanol gas-sensing response of the pristine ZnO–WO3 composite nanorods. The experimental results herein demonstrated a proper thermal annealing procedure of the binary composite nanorods is a promising approach to modulate the gas-sensing behavior the binary oxide composite nanorods. Full article
Show Figures

Figure 1

Open AccessArticle
Manufacture of Networks from Large Diameter Single-Walled Carbon Nanotubes of Particular Electrical Character
Nanomaterials 2019, 9(4), 614; https://doi.org/10.3390/nano9040614 - 14 Apr 2019
Cited by 1
Abstract
We have demonstrated that the aqueous two-phase extraction (ATPE) can differentiate between large diameter single-walled carbon nanotubes (CNTs) by electrical character. Introduction of “hydration modulators” to the ATPE machinery has enabled us to isolate metallic and semiconducting CNTs with ease. We have also [...] Read more.
We have demonstrated that the aqueous two-phase extraction (ATPE) can differentiate between large diameter single-walled carbon nanotubes (CNTs) by electrical character. Introduction of “hydration modulators” to the ATPE machinery has enabled us to isolate metallic and semiconducting CNTs with ease. We have also shown that often there is a trade-off between the purity of the obtained fractions and the ability to separate both metallic and semiconducting CNTs at the same time. To isolate the separated CNTs from the matrices, we have proposed a method based on precipitation and hydrolysis, which can eliminate the need to use lengthy dialysis routines. In the final step, we prepared thin free-standing films from the sorted material and probed how electrical charge is transported through such macroscopic ensembles. Full article
Show Figures

Graphical abstract

Open AccessArticle
A Facile One-Step Synthesis of Cuprous Oxide/Silver Nanocomposites as Efficient Electrode-Modifying Materials for Nonenzyme Hydrogen Peroxide Sensor
Nanomaterials 2019, 9(4), 523; https://doi.org/10.3390/nano9040523 - 03 Apr 2019
Abstract
Cuprous oxide/silver (Cu2O/Ag) nanocomposites were prepared via a facile one-step method and used to construct an electrochemical sensor for hydrogen peroxide (H2O2) detection. In this method, AgNO3 and Cu(NO3)2 were reduced to Cu [...] Read more.
Cuprous oxide/silver (Cu2O/Ag) nanocomposites were prepared via a facile one-step method and used to construct an electrochemical sensor for hydrogen peroxide (H2O2) detection. In this method, AgNO3 and Cu(NO3)2 were reduced to Cu2O/Ag nanocomposites by glucose in the presence of hexadecyl trimethyl ammonium bromide (CTAB) at a low temperature. The optimum condition was the molar ratio of silver nitrate and copper nitrate of 1:10, the temperature of 50 °C. Under this condition, Cu2O/Ag nanocomposites were obtained with uniformly distributed and tightly combined Cu2O and Ag nanoparticles. The size of Cu2O particles was less than 100 nm and that of Ag particles was less than 20 nm. Electrochemical experiments indicate that the Cu2O/Ag nanocomposites-based sensor possesses an excellent performance toward H2O2, showing a linear range of 0.2 to 4000 μM, a high sensitivity of 87.0 μA mM−1 cm−2, and a low detection limit of 0.2 μM. The anti-interference capability experiments indicate this sensor has good selectivity toward H2O2. Additionally, the H2O2 recovery tests of the sensor in diluted milk solution signify its potential application in routine H2O2 analysis. Full article
Show Figures

Figure 1

Open AccessArticle
Hydrothermal Synthesis of CeO2-SnO2 Nanoflowers for Improving Triethylamine Gas Sensing Property
Nanomaterials 2018, 8(12), 1025; https://doi.org/10.3390/nano8121025 - 08 Dec 2018
Cited by 8
Abstract
Developing the triethylamine sensor with excellent sensitivity and selectivity is important for detecting the triethylamine concentration change in the environment. In this work, flower-like CeO2-SnO2 composites with different contents of CeO2 were successfully synthesized by the one-step hydrothermal reaction. [...] Read more.
Developing the triethylamine sensor with excellent sensitivity and selectivity is important for detecting the triethylamine concentration change in the environment. In this work, flower-like CeO2-SnO2 composites with different contents of CeO2 were successfully synthesized by the one-step hydrothermal reaction. Some characterization methods were used to research the morphology and structure of the samples. Gas-sensing performance of the CeO2-SnO2 gas sensor was also studied and the results show that the flower-like CeO2-SnO2 composite showed an enhanced gas-sensing property to triethylamine compared to that of pure SnO2. The response value of the 5 wt.% CeO2 content composite based sensor to 200 ppm triethylamine under the optimum working temperature (310 °C) is approximately 3.8 times higher than pure SnO2. In addition, CeO2-SnO2 composite is also significantly more selective for triethylamine than pure SnO2 and has better linearity over a wide range of triethylamine concentrations. The improved gas-sensing mechanism of the composites toward triethylamine was also carefully discussed. Full article
Show Figures

Figure 1

Back to TopTop