TiO
2
nanoparticles (NPs) are widely used in the environmental engineering, medicine, chemical and food industries due to their unique photocatalytic and biocidal properties. NPs may generate ...reactive oxygen species and, hence, have the toxic effect on the living cells via oxidative stress. An external UV irradiation may magnify the photocatalytic properties of TiO
2
NPs. In this regard, we have analyzed the influence of TiO
2
NPs on the conformation and thermal stability of native DNA in a buffer suspension without and under UV irradiation exploiting absorption spectroscopy and thermal denaturation in the range of 20–94 °C. The TiO
2
NPs size distribution and polydispersity index were examined by dynamic light scattering (DLS) and confirmed by TEM. The DNA:TiO
2
NPs assemblies were revealed and characterized by DLS and TEM. Upon heating the DNA suspension with TiO
2
NPs from about 25 to 44 °C we have observed decreasing the hyperchromicity coefficient (
h
) on the DNA melting curves. That is explained by the intensive formation of the DNA:TiO
2
NPs assemblies. We have revealed, that partial DNA disordering appears at initial contacts with NPs. DNA binding to TiO
2
NPs is manifested in the change of the DNA melting temperature (
T
m
). We showed that the performed UV treatment of DNA during 3 h leads to partial unwinding of the biopolymer structure. The NPs injection to the biopolymer suspension induced the additional effect on the DNA thermal stability under UV irradiation. The performed analysis of the experimental data suggests that the nature of the impact of NPs on the biopolymer is complex.
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•The J-aggregates of cationic cyanine dye amphi-PIC interact with bovine serum albumin (BSA) molecules in a buffer solution.•BSA forms complexes with the J-aggregates.•amphi-PIC ...J-aggregates in the complexes with BSA didn’t agglomerate in the solution.•Fluorescence properties of the J-aggregates in the complexes are improved.•Stability and photostability of J-aggregates in the complexes with serum albumins are increased.
The aggregation behavior of amphiphilic pseudoisocyanine (amphi-PIC) dye in solutions with bovine serum albumin (BSA) has been studied by optical spectroscopy. Typically, the interaction of serum albumin molecules with J-aggregates leads to their disaggregation with individual monomers binding to albumins. However, it has been found that BSA molecules form complexes with amphi-PIC J-aggregates improving their spectral properties, like fluorescence quantum yield and absorption. The stability and photostability of the J-aggregates in the complexes appeared to be significantly increased. As the main reason for the improvement of amphi-PIC J-aggregates properties, their agglomeration prevention has been supposed.
In this work, to obtain textile triboelectric layers for wearable flexible triboelectric nanogenerators (TENGs), we used two modes of growing nanostructured zinc oxide (ZnO) arrays on a carbon fabric ...(CF) using the automatic Successive Ionic Layer Adsorption and Reaction (SILAR) method. To produce a CF/ZnO_nr triboelectric textile with an array of intergrown short ZnO nanorods, we used a pre-coating of carbon fibers with ZnO seed layers. When the ZnO layer was fabricated by automatic SILAR on bare carbon fabric, we obtained the CF/ZnO_ns textile with an array of interconnected ZnO nanosheets 50–100 nm thick. As a proof of concept, we developed and tested two prototypes of flexible vertical contact–separation mode CF/ZnO_nr/PET/ITO and CF/ZnO_ns/PET/ITO TENGs, in which a gap was involuntarily formed between the smooth PET layer and the woven carbon textile coated with nanostructured ZnO films. In pressing tests with a force of ~5 N (pressure ~33 kPa), the CF/ZnO_ns/PET/ITO TENG created a higher open-circuit voltage up to 30 V and a higher maximum surface charge density of 1.3 μC/m2. In the successive press–release tests, this TENG showed an output voltage of 3.6 V, a current density of 1.47 μA/cm2, and a power density of 1.8 µW/cm2, confirming its effectiveness.
TiO
2
nanoparticles (NPs) have unique photocatalytic properties, which are used in food industries, medicine, biosensorics, and solar energy conversion. Since the toxic properties of TiO
2
NPs have ...been insufficiently studied, additional information on the molecular mechanisms of their biological action on the structure and stability of biological macromolecules is needed, especially concerning DNA. In this work exploiting the differential UV–visible spectroscopy, the effect of the heating (from 20 to 90 °C) and concentration of TiO
2
NPs ((1–3) × 10
−
4
M) on a conformation of native DNA adsorbed on TiO
2
NPs in a buffer solution (pH 5) is studied. Analysis of dynamic light scattering (DLS) data for the DNA:TiO
2
NP suspension revealed that when the temperature increases the separated DNA:TiO
2
NP nanoassemblies form nanoaggregates. Correlation between the thermal dependency of the DLS data and thermal DNA denaturation measurements indicated that the appearance of the single-stranded unwound regions in double-stranded DNA in the suspension with temperature rise promotes the effective formation of the DNA:TiO
2
NP nanoaggregates.
Graphical abstract
The electrical resistivity of three samples is measured in the range 4.2–295 K. One sample contains the pure Ti3AlC2 MAX‐phase, and the other two samples contain this phase together with inclusions ...of TiC, TiO, and Al2O3 phases. To estimate the value of the residual resistivity of the TiC phase, data of energy‐dispersive X‐ray spectroscopy concentration distributions of elements are used. Estimations show that the Ti3AlC2 phase has the smallest residual resistivity of all phases and can electrically shunt other phases. The approximation of temperature dependences of the resistivity reveals that the Bloch–Grüneisen term of scattering of electrons on phonons (i.e., the term proportional to T5) increases strongly with the increase of volume fractions of inclusions. According to the proposed explanation of this effect, interstitial impurities of the carbon in the Ti3AlC2 phase migrate to neighbor crystals of the titanium carbide during the formation of the MAX phase, so the purification of this phase from carbon appears. As all other phases are electrically shunted by the Ti3AlC2 phase, the Bloch–Grüneisen term of the resistivity of this purified Ti3AlC2 phase increases.
Electrical resistivity of three samples containing the pure Ti3AlC2 hexagonal phase and this phase with inclusions of TiC, TiO, and Al2O3 is measured at 4.2–295 K. The Bloch–Grüneisen term of electron scattering on phonons increases in samples with inclusions. According to the proposed explanation, interstitial carbon atoms migrate into the TiC phase, so the Ti3AlC2 phase is purified.
The electrical resistivity of three samples is measured in the range 4.2–295 K. One sample contains the pure Ti
3
AlC
2
MAX‐phase, and the other two samples contain this phase together with ...inclusions of TiC, TiO, and Al
2
O
3
phases. To estimate the value of the residual resistivity of the TiC phase, data of energy‐dispersive X‐ray spectroscopy concentration distributions of elements are used. Estimations show that the Ti
3
AlC
2
phase has the smallest residual resistivity of all phases and can electrically shunt other phases. The approximation of temperature dependences of the resistivity reveals that the Bloch–Grüneisen term of scattering of electrons on phonons (i.e., the term proportional to
T
5
) increases strongly with the increase of volume fractions of inclusions. According to the proposed explanation of this effect, interstitial impurities of the carbon in the Ti
3
AlC
2
phase migrate to neighbor crystals of the titanium carbide during the formation of the MAX phase, so the purification of this phase from carbon appears. As all other phases are electrically shunted by the Ti
3
AlC
2
phase, the Bloch–Grüneisen term of the resistivity of this purified Ti
3
AlC
2
phase increases.
In the infrastructure of the future, based on intelligent computerized systems and control and monitoring devices, the smart home is part of the Internet of Things (IoT). However, in addition to the ...need to address energy consumption, the widespread adoption of smart homes may also exacerbate the growing problem of increasing amounts of non-recyclable e-waste from IoT devices. Compared to synthetic plastics, biopolymers offer many unique advantages such as robust structure, light weight, mechanical flexibility, biocompatibility, biodegradability and renewability. Biopolymers, which are abundant in natural products such as cellulose, silk fibroin, polylactic acid, chitosan, collagen, keratin, alginate, starch and gelatin, have great promise for the production of environmentally friendly Internet of Things devices. They are ideal candidates for the use of low-temperature sol–gel coating and ink-printing processes to facilitate the development of low-cost, large-area flexible electronic devices. This work presents developments known from the literature, as well as the results of original research on the use of biopolymer materials to create flexible, wearable and textile electronic devices, such as sensors, energy storage devices and nanogenerators, soft hydrogel actuators and wireless communication devices that are promising for the Internet of Things but have not yet been implemented in smart homes.
Graphical Abstract
With the use of two independent in situ methods, the crystallization temperature of supercooled bismuth in a Bi/V contact pair was measured. It was shown that the condensation mechanism of the ...fusible component does not affect the achieved supercooling value, which is somewhat higher than 0.3 of the melting point. However, the temperature width of the crystallization range in the samples obtained by the condensation through the vapor-crystal mechanism is larger than in those obtained using the vapor-liquid condensation mechanism. The observed peculiarities are explained by the interrelationship between the morphology and the mechanism of condensation of the samples.
In this work, we have developed an automatic low temperature, cheap, simple and scalable chemical method Successive Ionic Layer Adsorption and Reaction (SILAR) to obtain layers of two-dimensional ...zinc oxide (ZnO) nanostructures from aqueous solutions. The ZnO networked nanosheets obtained by the automatic SILAR method have high adhesion to the glass substrate and improved mechanical resistance, which was confirmed by scratch adhesion tests performed by applying a progressive load. The value of the normal force Fz = 2.6 N, corresponding to the critical load Lc, for networked ZnO nanosheets is greater than for a conventional array of ZnO nanorods, for which Fz = 2.1 N.
TiO\(_{2}\) nanoparticles (NPs) have unique photocatalytic properties, which are used in food industries, medicine, biosensorics, and solar energy conversion. Since the toxic properties of ...TiO\(_{2}\) NPs have been insufficiently studied, additional information on the molecular mechanisms of their biological action on the structure and stability of biological macromolecules is needed, especially concerning DNA. In this work exploiting the differential UV-visible spectroscopy, the effect of the heating (from 20 till 90 \(^0\)C) and concentration of TiO\(_{2}\) NPs ((1-3)\(\times\)10$^-$$^4\( M) on a conformation of native DNA adsorbed on TiO\)_{2}\( NPs in a buffer solution (pH 5) is studied. Analysis of dynamic light scattering (DLS) data for the DNA:TiO\)_{2}\( NPs suspension revealed that when the temperature increases the separated DNA:TiO\)_{2}\( NP nanoassemblies form nanoaggregates. Correlation between the thermal dependency of the DLS data and thermal DNA denaturation measurements indicated that the appearance of the single-stranded unwound regions in double-stranded DNA in the suspension with temperature rise promotes the effective formation of the DNA:TiO\)_{2}$ NPs nanoaggregates.
