Bombesin receptor-targeted liposomes for enhanced delivery to lung cancer cells

• Mohammad J. Akbar,
• Pâmela C. Lukasewicz Ferreira,
• Melania Giorgetti,
• Leanne Stokes and
• Christopher J. Morris

Beilstein J. Nanotechnol. 2019, 10, 2553–2562, doi:10.3762/bjnano.10.246

• relative cellular accumulation (data not shown). To overcome this, the density of targeting lipid was increased to 3 mol %. To examine for active internalisation and intracellular accumulation of liposomes at the endocytosis permissive temperature of 37 °C, we subtracted the median fluorescence intensity

• (MFI) attributable to cell-surface adsorption of liposomes at 4 °C, to yield a “normalised cell MFI” at each time point and for each formulation. For non-targeted FL-Control-lipo, there was a modest increase in normalised fluorescence over time (blue bars, Figure 4a). In contrast, the fluorescence of

• FL-Target-lipo increased over time (red bars, Figure 4a). Drawing comparison between the control and targeted liposome groups, it was clear to see that at 15 min, fluorescence was no greater in cells treated with FL-Target-lipo compared to FL-Control-lipo. However, at 60 min and beyond cell

Evaluation of click chemistry microarrays for immunosensing of alpha-fetoprotein (AFP)

• Seyed Mohammad Mahdi Dadfar,
• Sylwia Sekula-Neuner,
• Vanessa Trouillet,
• Hui-Yu Liu,
• Ravi Kumar,
• Annie K. Powell and
• Michael Hirtz

Beilstein J. Nanotechnol. 2019, 10, 2505–2515, doi:10.3762/bjnano.10.241

• was spotted onto them via microchannel cantilever spotting (µCS). Based on the fluorescence measurements, the optimal microarray design was found and its sensitivity was determined. Keywords: alpha-fetoprotein (AFP); cancer biomarker; click chemistry; fluorescent immunosensor; hepatocellular

• spotted onto the surfaces via µCS. The microarrays were incubated for performing antigen–antibody interaction for different times (10 to 60 min) and at different temperatures (room temperature of 25 °C and elevated physiological temperature of 37 °C). Then, the samples were washed and the fluorescence

• signal of the spot array was quantified (Figure 4). As a general trend, higher fluorescence intensities are observed at an elevated temperature of 37 °C for all microarrays at the same incubation time. For room temperature incubation, the observed fluorescence intensity increases with incubation time for

Formation of metal/semiconductor Cu–Si composite nanostructures

• Natalya V. Yumozhapova,
• Andrey V. Nomoev,
• Vyacheslav V. Syzrantsev and
• Erzhena C. Khartaeva

Beilstein J. Nanotechnol. 2019, 10, 2497–2504, doi:10.3762/bjnano.10.240

• silicon are concentrated in the core and on the surface of the particle, respectively. The X-ray fluorescence analysis (EDX) of Cu–SiOx nanoparticles, taken on a section of size 500 × 500 nm (Figure 7c), confirms that the particles consist of copper, silicon, and oxygen. The nanoparticles are stable

Small protein sequences can induce cellular uptake of complex nanohybrids

• Jan-Philip Merkl,
• Malak Safi,
• Christian Schmidtke,
• Fadi Aldeek,
• Johannes Ostermann,
• Tatiana Domitrovic,
• Sebastian Gärtner,
• John E. Johnson,
• Horst Weller and
• Hedi Mattoussi

Beilstein J. Nanotechnol. 2019, 10, 2477–2482, doi:10.3762/bjnano.10.238

• ]. We found that once uploaded onto an amylose-filled column, the nanohybrid stayed tightly bound to the column even after several washes with buffer. The bimodal character of the hybrid is reflected in the pinkish colour of the AuNPs and the fluorescence of the QDs of the immobilized band in the

• consisting of 100 nM QD solution, 2 equivalents of LA-ZW-AuNP per QD and 14 equivalents His6-MBP-γ per AuNPs, were incubated with the cell culture for 1 h. Following rinsing the culture was imaged using epifluorescence and confocal fluorescence microscopy. A pronounced intracellular uptake of the hybrids was

• observed, as indicated by the significant fluorescence staining of the cells (see Figure 1D). Additional confocal images collected from two sets of cultures, one incubated with nanohybrids prepared with His6-MBP-γ and the other with His6-MBP (gamma-free MBP), and serving as control. Only the culture

Self-assembly of a terbium(III) 1D coordination polymer on mica

• Quentin Evrard,
• Giuseppe Cucinotta,
• Felix Houard,
• Guillaume Calvez,
• Yan Suffren,
• Carole Daiguebonne,
• Olivier Guillou,
• Andrea Caneschi,
• Matteo Mannini and
• Kevin Bernot

Beilstein J. Nanotechnol. 2019, 10, 2440–2448, doi:10.3762/bjnano.10.234

• . Luminescence measurements. Luminescence emission spectra were measured with a Horiba Jobin-Yvon Fluorolog-III fluorescence spectrometer equipped with a 450 W Xe lamp. The emission signal was collected in the 190–860 nm range via a Hamamatsu R928 UV–vis photomultiplier. The sample emission was measured directly

pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

• Saban Kalay,
• Yurij Stetsyshyn,
• Volodymyr Donchak,
• Khrystyna Harhay,
• Ostap Lishchynskyi,
• Halyna Ohar,
• Yuriy Panchenko,
• Stanislav Voronov and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2019, 10, 2428–2439, doi:10.3762/bjnano.10.233

• functionalization of BNNTs was confirmed by spectroscopic, gravimetric and imaging techniques. In contrast to “pure” BNNTs, P(AA-co-FA)-functionalized BNNTs demonstrate intense green fluorescence emission at 520 nm. Under neutral or alkaline pH values, P(AA-co-FA)-functionalized BNNTs are highly emissive in

• (DU145) and are suitable for further evaluation in cellular imaging applications. Keywords: boron nitride nanotubes; cellular imaging; fluorescence; pH switching; polymer brushes; surface modification; Introduction In recent years, considerable effort has been devoted to the development of hybrid

• commonly used labels is fluorescein [37][38][39][40][41][42]. In biomedical applications, fluorescein has several advantages over other dyes such as nontoxicity, high water solubility, and pH responsivity. Fluorescein demonstrates a high fluorescence efficiency at basic pH values but becomes nonfluorescent

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• narrow emission bands in the ultraviolet/visible/NIR upon excitation in the NIR range where light absorption and scattering from biological tissues is minimal as well as long fluorescence lifetimes in the microsecond range that are insensitive to oxygen, a high chemical stability and a low cytotoxicity

• excitation power density, this can influence both the UCL intensity and the UCL spectral distribution. In general, the coating with a thick silica shell is not expected to strongly affect the brightness of the UCNPs as long as the two properties absorption cross section and fluorescence quantum yield, which

• such as peptides, antibodies or nucleic acids for bioimaging applications or fluorescence assays. The growth of a mesoporous silica shell on a microporous silica shell can also be applied for the subsequent use of these nanomaterials for drug loading and delivery [69]. Experimental All syntheses were

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• implanted with H+ ions to produce an ensemble of color centers at a depth of approximately 2 μm. The samples were in part annealed at different temperatures (750 and 900 °C) to selectively produce distinct color centers. For all these color centers we saw an enhancement of the photostable fluorescence

• the near-infrared, there is a need to improve the spontaneous emission rate for room-temperature applications such as magnetic sensing and SPSs. For all the above applications, the fluorescence emission enhancement of the color centers is a crucial issue for room-temperature applications, specifically

• the VSiVC and NCVSi. A detailed confocal microscopy study of NCVSi in the pillars is given in the next section. A summary of the PL-measured color centers in each sample is reported in Table 1. Confocal microscopy Confocal fluorescence scanning microscopy was performed using two custom-built systems

Polyvinylpyrrolidone as additive for perovskite solar cells with water and isopropanol as solvents

• Chen Du,
• Shuo Wang,
• Xu Miao,
• Wenhai Sun,
• Yu Zhu,
• Chengyan Wang and
• Ruixin Ma

Beilstein J. Nanotechnol. 2019, 10, 2374–2382, doi:10.3762/bjnano.10.228

• monochromator. Infrared (IR) spectroscopy was performed using a Fourier transform IR spectrometer (VERTEX80v, Bruker). Photoluminescence (PL) spectra and the fluorescence decay curves were recorded with a computer controlled, modular spectro- fluorimeter (FLS980, Edinburgh). The active area of the cell was 0.1

Atomic force acoustic microscopy reveals the influence of substrate stiffness and topography on cell behavior

• Yan Liu,
• Li Li,
• Xing Chen,
• Ying Wang,
• Meng-Nan Liu,
• Jin Yan,
• Liang Cao,
• Lu Wang and
• Zuo-Bin Wang

Beilstein J. Nanotechnol. 2019, 10, 2329–2337, doi:10.3762/bjnano.10.223

• distribution of molecules. However, many native tissues are not homogeneously stiff and it is not clear whether the controlled presentation of rigid and flexible material axes on the substrate governs the cytoskeletal and nuclear morphology [14]. Several techniques such as fluorescence microscopy [14][15

• ], confocal microscopy, scanning electron microscopy (SEM) [12] and atomic force microscopy (AFM) [16][17] have been employed to investigate cell–substrate interactions. Fluorescence and confocal microscopy are traditional techniques to investigate the intra- and intercellular processes in biological studies

• topography is determined by both the exposure dose and the development of the SU-8 films. We cultured L929 cells on undeveloped and developed SU-8 surfaces as well as on a reference glass substrate. The structural responses of the L929 cells on the substrate topography were probed using AFAM. A fluorescence

Design of a nanostructured mucoadhesive system containing curcumin for buccal application: from physicochemical to biological aspects

• Sabrina Barbosa de Souza Ferreira,
• Gustavo Braga,
• Évelin Lemos Oliveira,
• Jéssica Bassi da Silva,
• Hélen Cássia Rosseto,
• Lidiane Vizioli de Castro Hoshino,
• Mauro Luciano Baesso,
• Wilker Caetano,
• Craig Murdoch,
• Helen Elizabeth Colley and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2019, 10, 2304–2328, doi:10.3762/bjnano.10.222

• in comparison to pH 7 at 37 °C. These results could be explained by new chemical species from pKa that do not appear in the emission spectra due to the excitation wavelength of 422 nm (CUR maximum absorption). Anisotropy of fluorescence (r) was also investigated for the samples with maximum peak

• spectral emission (Table 1). Anisotropy is considered a powerful technique to investigate the molecular dynamics of fluorescent solutes, such as CUR. During the fluorescence analysis, the molecules are excited by linearly polarized light, and they absorb and emit the fluorescence in a polarized way. If the

• ]. Furthermore, the temperature changes were more remarkable than the variation in pH, with the systems investigated at 45 °C displaying higher anisotropy values in comparison to those evaluated at 37 °C. Incorporation kinetics Incorporation kinetics were evaluated by observing the fluorescence emission

Microfluidics as tool to prepare size-tunable PLGA nanoparticles with high curcumin encapsulation for efficient mucus penetration

• Nashrawan Lababidi,
• Valentin Sigal,
• Aljoscha Koenneke,
• Konrad Schwarzkopf,
• Andreas Manz and
• Marc Schneider

Beilstein J. Nanotechnol. 2019, 10, 2280–2293, doi:10.3762/bjnano.10.220

• were of HPLC grade. Fluorescence labelling of PLGA In a first step 1.1 equiv of rhodamine B was dissolved in dried dichloromethane (DCM) and activated with 1.5 equiv of dicyclohexylcarbodiimide (DCC, Scheme 1). This solution was stirred at room temperature. Subsequently, a solution with 1 equiv of PLGA

• within the mucus sample were obtained at constant distance from the bottom of the slide. The permeability of PLGA NPs through mucus was tracked by the change in the fluorescence signal. This approach allowed us to study the size-dependent permeation of PLGA NP through pulmonary human mucus. One day

• nanoparticles stabilized with different types of Pluronic before and after their distribution and interaction with mucin. xz-micrographs taken in confocal laser scanning microscopy study of the penetration of differently sized F68-stabilized PLGA NPs. Fluorescently labelled (red fluorescence) 60, 120 and 400 nm

Use of data processing for rapid detection of the prostate-specific antigen biomarker using immunomagnetic sandwich-type sensors

• Camila A. Proença,
• Tayane A. Freitas,
• Thaísa A. Baldo,
• Elsa M. Materón,
• Flávio M. Shimizu,
• Gabriella R. Ferreira,
• Frederico L. F. Soares,
• Ronaldo C. Faria and
• Osvaldo N. Oliveira Jr.

Beilstein J. Nanotechnol. 2019, 10, 2171–2181, doi:10.3762/bjnano.10.210

• diseases [1]. Protein biomarkers are commonly measured using conventional immunoassays such as enzyme-linked immuno-sorbent assay (ELISA) [1], radioimmunoassay (RIA) [2], fluorescence methods [3], and chemiluminescence [4]. Unfortunately, these standard methodologies have high cost, long analysis times

BergaCare SmartLipids: commercial lipophilic active concentrates for improved performance of dermal products

• Florence Olechowski,
• Rainer H. Müller and
• Sung Min Pyo

Beilstein J. Nanotechnol. 2019, 10, 2152–2162, doi:10.3762/bjnano.10.208

• suspension was prepared containing 0.2% curcumin. Curcumin has many positive effects on the skin [31][32] and is at the same time fluorescent, allowing for a good and easy detection in the skin by fluorescence microscopy. The suspension was applied to pig ear skin in a covered Franz cell, incubated for 24 h

• and then skin slices were investigated by normal light and fluorescence microscopy (Figure 8, left column). Figure 8 (upper row) shows the fluorescence microscopy images. The lower row shows overlays of fluorescence and light microscopy images, allowing to locate the fluorescence in the epidermis. For

• comparison, a tenfold higher concentrated 2% curcumin suspension is shown in Figure 8 (middle column). The curcumin remains as a thick fluorescent layer on top of the stratum corneum, showing practically no fluorescence inside the epidermis. Finally, a curcumin containing marketed product from the US is

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

• illumination [7]. The characterization of single NV centers became popular at the end of the 1990s. It was demonstrated that the fluorescence of single NV centers can be detected by room-temperature fluorescence microscopy and that the defect shows perfect photostability [8]. Room-temperature optically

• alternating magnetic field in a traditional fluorescence microscope. As NV centers can be placed much closer to the sample, within a few nanometers of the surface, NV magnetometry has a clear advantage over conventional methods [28][29]. The interaction between the NV center and the sample can be carried out

• cell can be directly used as a fluorescence probe and temperature sensor. A review on the use of fluorescent NDs for tracking in living cells is given in [40] and [41]. Later in this review, we discuss cell temperature mapping by ND NV spins. Direct magnetic imaging in cells using NDs has not yet been

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• Instruments, USA). The pore size distribution was calculated using the Barret–Joyner–Halenda (BJH) method. The photoluminescence (PL) was measured on a fluorescence spectrophotometer (F-4500, Hitachi, Japan). Electron spin resonance (ESR) signals of the reactive species spin trapped by 5,5-dimethyl-1

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• processes, such as catalytic reactions and fluorescence quenching, often improves sensor capabilities through component nanoarchitectonics. Imanaka and co-workers used a combustion process induced by a precious-metal-free CeO2–ZrO2–ZnO catalyst for CO gas detection [87]. The semiconducting (p-type) La2CuO4

• fluorescent gelators containing a tris(β-diketonato) complex with appropriate metals. The presence of amines can be found through fluorescence-quenching efficiencies of the thin layer films of the gel materials. The prepared films are most sensitive to the detection of tertiary amines. The discrimination and

• having chiral ʟ-serine and ʟ-threonine to discriminate enantiomers of N-acetyl amino acid anions through ratiometric fluorescence analysis. Torsi and co-workers adopted odorant binding proteins to discriminate chiral substances [90]. They immobilized odorant binding proteins to the gate of a water-gated

Optimization and performance of nitrogen-doped carbon dots as a color conversion layer for white-LED applications

• Tugrul Guner,
• Hurriyet Yuce,
• Didem Tascioglu,
• Eren Simsek,
• Umut Savaci,
• Aziz Genc,
• Servet Turan and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 2004–2013, doi:10.3762/bjnano.10.197

• the blue (430 nm), green (500 nm) and red (630 nm) fluorescence, the AC-CDots can produce a pure white-light emission spectrum. Finally, highly efficient CDot/gel glass, phosphor-based, trichromatic WLEDs were developed by Yuan et al. [50]. The authors doped green and red CDots into a matrix of

Gold-coated plant virus as computed tomography imaging contrast agent

• Alaa A. A. Aljabali,
• Mazhar S. Al Zoubi,
• Khalid M. Al-Batanyeh,
• Ali Al-Radaideh,
• Mohammad A. Obeid,
• Abeer Al Sharabi,
• Walhan Alshaer,
• Bayan AbuFares,
• Tasnim Al-Zanati,
• Murtaza M. Tambuwala,
• Naveed Akbar and
• David J. Evans

Beilstein J. Nanotechnol. 2019, 10, 1983–1993, doi:10.3762/bjnano.10.195

• −53.8 ± 2.4 mV upon antibody coating of the particles. The zeta potential value of VCAM1-PEG5000Au-CPMV becomes more negative [38], which is consistent with the literature [42]. In vitro fluorescent cell imaging Confocal fluorescence microscopy was performed on the cell lines to demonstrate the

• . Fluorescence microscopy confirmed that the VCAM1-PEG5000Au-CPMV can selectively bind to their target, whereas, the IgG-PEG5000Au-CPMV control did not show any fluorescence signal, which is indicative that no binding to the surface of the cells occurred (Figure 4A). The merged confocal microscopy image in

• analyzed with a fluorescence microscope (Cytation Cell Imager; BioTek Instruments, Inc). Transmission electron microscopy TEM images were recorded using a Titan FEI microscope, operating at 300 kV and fitted with a post-column Gatan Tridiem GIF 863 imaging filter. Samples were dispersed in water at a

Engineered superparamagnetic iron oxide nanoparticles (SPIONs) for dual-modality imaging of intracranial glioblastoma via EGFRvIII targeting

• Xianping Liu,
• Chengjuan Du,
• Haichun Li,
• Ting Jiang,
• Zimiao Luo,
• Zhiqing Pang,
• Daoying Geng and
• Jun Zhang

Beilstein J. Nanotechnol. 2019, 10, 1860–1872, doi:10.3762/bjnano.10.181

• visualization of pathophysiological processes with high sensitivity but with relatively low spatial resolution and shallow penetration into the tissue [30][31]. Cyanine7.5 NHS ester (Cy7.5), a near infrared fluorescence dye, has attracted extensive attention from researchers in various fields, including optical

• -EGFRvIII cells was carried out on cells digested and gathered through centrifugation at 1000 rpm for 4 min. Finally, 0.5 mL of PBS (0.01 M, pH 7.4) was used to suspend the cells and the fluorescence intensity of the cells was ascertained by flow cytometry (BD, USA). U87MG and U87MG-EGFRvIII cells were

• seeded into 24-well plates and cultured for 24 h. When the cells reached 80% confluence, they were incubated with 5-FAM-labled PEPHC1 (1 mg/mL) for 1 h. For fluorescence imaging, the culture solution was discarded, and the cells were incubated with 4% paraformaldehyde solution for 15 minutes at room

Nanoarchitectonics meets cell surface engineering: shape recognition of human cells by halloysite-doped silica cell imprints

• Elvira Rozhina,
• Ilnur Ishmukhametov,
• Svetlana Batasheva,
• Farida Akhatova and
• Rawil Fakhrullin

Beilstein J. Nanotechnol. 2019, 10, 1818–1825, doi:10.3762/bjnano.10.176

• previously published protocol [24][25]. Silica/halloysite-decorated HeLa cells were then imaged in situ with optical fluorescence microscopy. A typical image is shown in Figure 2A demonstrating the preserved cell morphology and characteristic nuclear DAPI stain. Next, we imaged the silica/halloysite

• (Figure 3F,G), confirming the viability of the encapsulated cells. CFSE-labelled HeLa cells divide, thus the overall fluorescence intensity decreases. In case of silica-encapsulated HeLa cells there was a prominent decrease in fluorescence intensity during day 1 of the observation, which we attribute to

• the inhibition of proliferation by the silica shells. On day 3, however, the fluorescence intensity in silica-coated cells was even higher than in the control cells, apparently due to the partial destruction of the shells and the release of HeLa cells. Although non-compromised viability is an

Toxicity and safety study of silver and gold nanoparticles functionalized with cysteine and glutathione

• Barbara Pem,
• Igor M. Pongrac,
• Lea Ulm,
• Ivan Pavičić,
• Valerije Vrček,
• Darija Domazet Jurašin,
• Marija Ljubojević,
• Adela Krivohlavek and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2019, 10, 1802–1817, doi:10.3762/bjnano.10.175

• wavelength of 535 nm. The untreated cells were used as negative controls, while cells treated with hydrogen peroxide (100 μM) served as positive controls. The data are expressed as percentage of fluorescence intensity compared to negative controls. The changes in the intracellular level of GSH were measured

• , incubated with MBCl (50 μM) for 20 min at 37 °C, washed again twice with PBS and analyzed using a VictorTM multilabel reader at an excitation wavelength of 355 nm and emission wavelength of 460 nm. The data are expressed as percentage of fluorescence intensity compared to negative controls. DNA damage in

• . After 48 h of treatment, the daphnids were washed with PB pH 7.4 and put on microscopic glass using cover slips mounted with Vectashield (Vector Laboratories, Burlingame, CA, USA). An Opton III RS fluorescence microscope (Opton Feintechnik, Oberkochen, Germany) with ×10 magnification was used for

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• changes of the molecular machines, for instance, to capture and release guest molecules [167][168], to rotate of molecular rotors [169][170], to open and close molecular pliers [171][172], or in indicator displacement assays of glucose based on fluorescence resonance energy transfer [173]. Subtle

• environments of closely packed nanorods (when the inter-rod distance was less than ca. 70 nm), enhanced excitation transfer was observed, indicating that fluorescence would be efficiently enhanced within well-aligned nanorods prepared at the air–water interface. Inorganic low-dimensional nanomaterials often

BiOCl/TiO₂/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

• Minlin Ao,
• Kun Liu,
• Xuekun Tang,
• Zishun Li,
• Qian Peng and
• Jing Huang

Beilstein J. Nanotechnol. 2019, 10, 1412–1422, doi:10.3762/bjnano.10.139

• CHI700E) with blue light (400–450 nm) irradiation. The steady-state photoluminescence (PL) spectra of the samples were detected by using a Hitachi F-7000 fluorescence spectrophotometer with excitation at 280 nm. Photocatalytic activity tests With visible-light irradiation, the photocatalytic activity was

Janus-micromotor-based on–off luminescence sensor for active TNT detection

• Ye Yuan,
• Changyong Gao,
• Daolin Wang,
• Chang Zhou,
• Baohua Zhu and
• Qiang He

Beilstein J. Nanotechnol. 2019, 10, 1324–1331, doi:10.3762/bjnano.10.131

• ], surface plasmon resonance [10], molecularly imprinted polymers [6], and fluorescence polarization [11] have been proposed to detect TNT. However, most of these techniques have major limitations such as cumbersome pretreatment, complicated operation, long detection time and high cost. In recent years

• surface charge of the UCNPs before and after modification was measured. As shown in Figure 1d, the zeta potential changed from −22.08 to 17.3 mV, indicating the successful surface amine group functionalization. Moreover, the fluorescence emission spectrum shows that the surface functionalization did not

• surface of the UCNPs could chemically recognize the TNT molecules efficiently and form a Meisenheimer complex which has a strong absorption within the emission spectrum of the UCNPs. Due to the fluorescence resonance energy transfer from the excited UCNPs to the complex, the luminescence intensity of the