Search

Due to its advantages of label-free and highly sensitive, the resistive pulse sensing with a nanopore has recently become even more potent for the discrimination of analytes in single molecule level. Generally, a transient interruption of ion current originated from the captured molecule passing through a nanopore will provide the rich information on the structure, charge and translocation dynamics of the analytes. Therefore, nanopore sensors have been widely used in the fields of DNA sequencing, protein recognition, and the portable detection of varied macromolecules and particles. However, the conventional nanopore devices are still lack of sufficient selectivity and sensitivity to distinguish more metabolic molecules involving ATP, glucose, amino acids and small molecular drugs because it is hard to receive a large number of identifiable signals with the fabricated pores comparable in size to small molecules for nanopore sensing. For all this, a series of innovative strategies developed in the past decades have been summarized in this review, including host-guest recognition, engineering alteration of protein channel, the introduction of nucleic acid aptamers and various delivery carriers integrating signal amplification sections based on the biological and solid nanopore platforms, to achieve the high resolution for the small molecules sensing in micro-nano environment. These works have greatly enhanced the powerful sensing capabilities and extended the potential application of nanopore sensors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ground-level O 3 pollution in the Pearl River Delta region (PRD) is closely related to anthropogenic, natural emissions and regional transport. However, the interactions among different sources and natural intervention in modulating anthropogenic management have not been comprehensively assessed. Here, the WRF-CMAQ-MEGAN modeling system was utilized to simulate an O 3 episode over PRD. The integrated source apportionment method (ISAM) and brute-force top-down combined with factor separation approach (BF-TD-FSA) were applied to quantify source contributions, impacts of individual or multiple sources on O 3 , and decouple interactions among various emissions; additionally, based on ISAM, O 3 isopleths visualized MDA8 O 3 response of different source types to anthropogenic perturbations. ISAM concluded considerable MDA8 O 3 contributions of regional transport in PRD/NPRD (non-PRD areas in Guangdong province) (38.8 %/35.7 %), followed by anthropogenic (32.7 %/24.8 %), BVOC (biogenic volatile organic compounds, 23.8 %/20.3 %) and SNO (soil NO, ∼4 %) emissions. Compared to concentrated anthropogenic contributions, widespread natural contributions were observed across their source areas and along the transport pathways. The BF-TD also revealed that regional transport had the largest impact (>90 μg m -3 ) on MDA8 O 3 while anthropogenic and BVOC emissions greatly affected downwind PRD (64.5 and 7.7 μg m -3 ). Negative synergy between anthropogenic and natural emissions (especially BVOC emission) suggested potential natural-induced intensification of anthropogenic impact during O 3 management. The MDA8 O 3 isopleths further demonstrated significant BVOC-induced reward and regional transport-induced penalty for anthropogenic NO x (ANO x ) emission control benefits, leading to additional maximum MDA8 O 3 decrease and increase by -27.5 and 13.8 μg m -3 in polluted high-emission grids. The natural-induced reward effect could impose loose requirements on anthropogenic reduction (decreased by 13.3 %-17.7 %) if there were no regional transport-induced control penalty. It is advisable to prioritize ANO x control and seek collaboration on air quality management with neighboring provinces to maximize the natural-induced control reward and achieve desired targets with minimal human efforts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The persistent O 3 pollution in the Beijing-Tianjin-Hebei (BTH) region remains unresolved, largely due to limited comprehension of O 3 -precursor relationship and photochemistry drivers. In this work, intraday O 3 sensitivity evolution from VOC-limited (volatile organic compound) regime in the forenoon to transition regime in the late afternoon was inferred by relative incremental reactivity (RIR) in summer 2019 at Xianghe, a suburban site in BTH region, suggesting that VOC-focused control policy could combine with stringent afternoon NO x control. Then detailed impacts of VOC subgroups on O 3 formation were further comprehensively quantified by parametric OH reactivity (K OH ), O 3 formation potential (OFP), as well as RIR weighted value and O 3 formation path tracing (OFPT) approach based on photochemical box model. O 3 episode days corresponded to stronger O 3 formation, depicted by higher K OH (10.4 s -1 ), OFP (331.7 μg m -3 ), RIR weighted value (1.2), and F(O 3 )-OFPT (15.5 ppbv h -1 ). High proportions of isoprene and OVOCs (oxygenated VOCs) to the total K OH and the OFPT method were demonstrated whereas results of OFP and RIR-weighted presented extra great impacts of aromatics on O 3 formation. The OFPT approach captured the process that has already happened and included final O 3 response to the original VOC, thus reliable for replicating VOC impacts. The comparison results of the four methods showed similarities when utilizing K OH and OFPT methods, which reveals that the potential applicability of simple K OH for contingency VOC control and more complex OFPT method for detailed VOC- and source-oriented control during policy-making. To investigate propulsion of VOC-involved O 3 photochemistry, atmospheric oxidation capacity (AOC) was quantified by two atmospheric oxidation indexes (AOI). Both AOIp_G (7.0 × 10 7 molec cm -3 s -1 , potential AOC calculated by oxidation reaction rates) and AOIe_G (8.5 μmol m -3 , estimated AOC given redox electron transfer for oxidation products) were stronger on O 3 episode days, indicating that AOC promoted the radical cycling initiated from VOC oxidation and subsequent O 3 production. Result-oriented AOIe_G reasonably characterized actual AOC inferred by good linear correlation between AOIe_G and O 3 concentrations compared to process-oriented AOIp_G. Therefore, with continuous NO x abatement, AOIe_G should be considered to represent actual AOC, also O 3 -inducing ability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Optical imaging and phototherapy in deep tissues face notable challenges due to light scattering. We use encoded acoustic holograms to generate three-dimensional acoustic fields within the target medium, enabling instantaneous and robust modulation of the volumetric refractive index, thereby noninvasively controlling the trajectory of light. Through this approach, we achieved a remarkable 24.3% increase in tissue heating rate in vitro photothermal effect tests on porcine skin. In vivo photoacoustic imaging of mouse brain vasculature exhibits an improved signal-to-noise ratio through the intact scalp and skull. These findings demonstrate that our strategy can effectively suppress light scattering in complex biological tissues by inducing low-angle scattering, achieving an effective depth reaching the millimeter scale. The versatility of this strategy extends its potential applications to neuroscience, lithography, and additive manufacturing.

A series of emission reduction measures were conducted in Wuhan, Central China, to ensure good air quality during the 7th Military World Games (MWG) in October 2019. To better understand the implications for ozone (O 3 ) pollution control strategies, we applied integrated analysis approaches based on the de-weathered statistical model, parameterization methods, chemical box model, and positive matrix factorization model. During the MWG, concentrations of O 3 , NO x , and volatile organic compound (VOCs), OFP (O 3 formation potential), L OH (OH radical loss rate) were 83 µg/m 3 , 43 µg/m 3 , 26 ppbv, 188 µg/m 3 , and 3.9 s -1 , respectively, which were 26%, 18%, 3%, 15%, and 13% lower than pre-MWG values and 6%, 39%, 30%, 33%, and 50% lower than post-MWG values, respectively. After removing meteorological influence, O 3 and its precursors during the MWG decreased largely compared with post-MWG values, and only O 3 , NO 2 , and oxygenated VOCs (OVOCs) declined compared with pre-MWG values, which revealed the emission reduction measures during the MWG played an important role for O 3 decline. For six VOCs sources, the mass contributions of biomass burning and solvents usage during the MWG decreased largely compared with pre-MWG values. O 3 production was sensitive to VOCs and the key species were aromatics, OVOCs, and alkenes, which originated mainly from solvents usage, biomass burning, industrial-related combustion, and vehicle exhaust. Decreasing O 3 concentration during the strict control was mainly caused by OVOCs reduction due to biomass burning control. Generally, the O 3 abatement strategies of Wuhan should be focused on the mitigation of high-reactivity VOCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

The Pearl River Delta (PRD) has long been plagued by severe O 3 pollution, particularly during the autumn. A regional O 3 pollution episode influenced by the Western Pacific Subtropical High in September 2021 was characterized by near-surface O 3 escalation due to strong photochemical reactions within the planetary boundary layer. This event was targeted to develop effective control strategies through investigation of precursor control type and scope based on the high-order decoupled direct method (HDDM) and integrated source apportionment method (ISAM) of CMAQ. Generally, the majority of areas (67.0 %) were under NO x -limited regime, which should strengthen afternoon NO x control inferred by positive convex O 3 responses. However, high emission and heavily polluted areas located in central PRD were under VOC-limited regime (11.6 %) or mixed regime (15.0 %). The remaining areas (6.4 %) were under NO x -titration or insensitive conditions. Regarding source apportionment, Guangdong province contributed 32.3 %-58.4 % to MDA8 O 3 of PRD, especially higher proportion (>50 %) to central areas. Overall, local-focused NO x /VOC emission reductions had limited effects on O 3 mitigation for receptor cities compared to regional-cooperative regulation. When region-wide VOC emission reduction was implemented, MDA8 O 3 in VOC-limited grids exhibited the largest declines (2.3 %-4.1 %, 3.9- 7.0 μg·m -3 ). However, unified NO x control contributed to increasing MDA8 O 3 in VOC-limited grids (most stations located for air quality evaluation) whereas decreased MDA8 O 3 by 2.1 %- 5.7 %, 3.0- 8.2 μg·m -3 in large-scale NO x -limited grids. The sensitivity-oriented regional control avoided O 3 rebound and achieved the greatest decline of 3.4 %- 5.0 %, 5.7- 8.4 μg·m -3 in VOC-limited grids; additionally, time-refined dynamic aggressive NO x control decreased peak O 3 by an extra 1.2- 6 μg·m -3 , both of which facilitate the regulation for the forecasting O 3 episodes. These findings suggest that in heavily polluted environments, the enhancement of O 3 regulation benefits requires meticulous, coordinated, and dynamic NO x and VOC controls spanning the entire region based on high-resolution analysis of heterogeneous O 3 -NO x -VOC sensitivity. Furthermore, emission reduction gains should be more reasonably reflected through increasing in-situ observations covering multi-sensitivity regions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Quercetin (Que) has been proven to enhance the chemosensitivity of multiple cancers, including colon cancer (CC). However, whether the combination of Que and 5-fluorouracil (5-FU) has a synergistic effect on drug-resistant CC cells has not previously been reported. The effect of Que (5 and 10 μg/mL) on cell vitality and apoptosis of CC and CC drug-resistant cells was examined using a cell counting kit-8 (CCK-8) and flow cytometry. After cells were treated with 5-FU (10, 40 μg/mL), Que (10 μM, 40 μM), or 5-FU in combination with Que, cell proliferation, apoptosis, oxidative stress-related factors, reactive oxygen species (ROS), and nuclear factor erythroid 2-related factor (Nrf2)/heme oxygenase-1 (HO-1) pathway-related factors were examined by colony formation assay, flow cytometry, ELISA, ROS kit, immunofluorescence assay, and Western blot. The results showed that 5-FU reduced cell viability and induced apoptosis of CC as well as 5-FU-resistant CC cells. Que further restrained the proliferation, oxidative stress-related factors (SOD, CAT, GPx, and GR), ROS production, and induced apoptosis in CC cells and 5-FU-resistant CC cells induced by 5-FU. Moreover, the combination of Que and 5-FU attenuated the Nrf2/HO-1 pathway-related marker levels in CC cells and 5-FU-resistant CC cells. Therefore, our results suggest that Que reverses 5-FU resistance in CC cells via modulating the Nrf2/HO-1 pathway.

Ultra-fast high-voltage switches (UFHVSs) are a core component of time-of-flight mass spectrometers for realizing high accuracy ion acceleration, deceleration, and temporal focusing. The desirable features of high performance UFHVSs include a large range of adjustability of pulse width, a high maximum output amplitude, and minute rising and falling times. Besides the simplicity of the driver circuit, the total cost of the whole device is also critical to its practical applications. In this work, we present a low-cost and easy-fabrication 5000 V bipolar solid-state UFHVS for a high-resolution mass spectrometer. A double-pulse transformer isolates the circuit's high- and low-voltage sides and synchronously drives series-connected cascode SiC FETs to form its push-pull topology. This scheme allows transmitting drive signals with long widths but without the magnetic saturation of the transformer. Testing results show that output pulses reach a maximum voltage of 5000 V and a width of 150 µs, with rising and falling times of 8.5 and 18.3 ns, respectively. More importantly, they have nearly no voltage decay., (© 2023 Author(s). Published under an exclusive license by AIP Publishing.)

The PM 2.5 -bounded elements were measured in outdoor and indoor from two urban middle schools in Xi'an. The PM 2.5 mass was from 42.4 to 283.7 µg/m 3 with bounded element from 3.4 to 41.7 µg/m 3 . Both the particle mass and the bounded elements displayed higher levels compared with previous studies in school environments. The most abundant elements were Ca, K, Fe, S, Zn and Cl both indoor and outdoor in two schools, which accounted for about 90% of the total elements. Strong correlations between indoor and outdoor were obtained along with relative effect from students' and teachers' activities on the indoor distributions between workdays and weekends. There had different indoor/outdoor (I/O) distributions for the two schools. It revealed the main outdoor sources for elements in JT and predominance of indoor sources in HT. The principal component analysis investigated main sources of elements in this study were coal combustion, geogenic dust and industrial emission, even though there displayed differences in the two school classrooms. The health risk assessment showed that the cancer risk for Ni and Pb was below the safe value while As and Cr might pose acceptable potential threat to both students' and teachers' health. The total non-cancer risks of accumulative multi-metals in JT exhibited to be higher than 1, indicating that there existed the potential non-carcinogenic health risks of exposure metals., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

The bonding and electronic properties of In n - , In n Si - , and In n Ge - (n = 3-16) clusters have been computationally investigated. An intensive global search for the ground-state structures of these clusters were conducted using the genetic algorithm coupled with density functional theory (DFT). The ground-state structures of these clusters have been identified through the comparison between simulated photoelectron spectra (PES) of the found lowest-energy isomers and the experimentally measured ones. Doping semiconductor atom (Si or Ge) can significantly change the structures of the In clusters in most sizes, and the dopant prefers to be surrounded by In atoms. There are three structural motifs for In n X - (X = Si, Ge, n = 3-16), and the transition occurs at sizes n = 5 and 13. All In n Si - and In n Ge - share the same configurations and similar electronic properties except for n = 8. Among all above studied clusters, In 13 - stands out with the largest vertical detachment energy (VDE), HOMO-LUMO gap, (E b ) and second order energy difference Δ 2 E due to its closed electronic shell of (1S) 2 (1P) 6 (1D) 10 (2S) 2 (1F) 14 (2P) 6 . Similarly, the neutral In 12 X (X = Si, Ge) clusters are also identified as superatoms but with electronic configuration of (1S) 2 (1P) 6 (2S) 2 (1D) 10 (1F) 14 (2P) 6 ., (© 2022 Wiley Periodicals LLC.)

Highly precise neuromodulation with a high efficacy poses great importance in neuroscience. Here we developed a candle soot fiber optoacoustic emitter (CSFOE), capable of generating a high pressure of over 10 MPa with a central frequency of 12.8 MHz, enabling highly efficient neuromodulation in vitro . The design of the fiber optoacoustic emitter, including the choice of the material and the thickness of the layered structure, was optimized in both simulations and experiments. The optoacoustic conversion efficiency of the optimized CSFOE was found to be 10 times higher than the other carbon-based fiber optoacoustic emitters. Driven by a single laser, the CSFOE can perform dual-site optoacoustic activation of neurons, confirmed by calcium (Ca 2+ ) imaging. Our work opens potential avenues for more complex and programmed control in neural circuits using a simple design for multisite neuromodulation in vivo ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chen, Shi, Lan, Wang, Li, Du, Hyman, Cheng and Yang.)

High precision neuromodulation is a powerful tool to decipher neurocircuits and treat neurological diseases. Current non-invasive neuromodulation methods offer limited precision at the millimeter level. Here, we report optically-generated focused ultrasound (OFUS) for non-invasive brain stimulation with ultrahigh precision. OFUS is generated by a soft optoacoustic pad (SOAP) fabricated through embedding candle soot nanoparticles in a curved polydimethylsiloxane film. SOAP generates a transcranial ultrasound focus at 15 MHz with an ultrahigh lateral resolution of 83 µm, which is two orders of magnitude smaller than that of conventional transcranial-focused ultrasound (tFUS). Here, we show effective OFUS neurostimulation in vitro with a single ultrasound cycle. We demonstrate submillimeter transcranial stimulation of the mouse motor cortex in vivo. An acoustic energy of 0.6 mJ/cm 2 , four orders of magnitude less than that of tFUS, is sufficient for successful OFUS neurostimulation. OFUS offers new capabilities for neuroscience studies and disease treatments by delivering a focus with ultrahigh precision non-invasively., (© 2022. The Author(s).)

In this article, a novel 2D/2D ultrathin Ti 3 C 2 /SnS 2 Schottky heterojunctions have been prepared via a facile hydrothermal process. The properties of the heterojunction were fully characterized. The photocatalytic degradation performance of composites was examined by photo-degradation of tetracycline hydrochloride (TC-HCL) under visible light irradiation. Compared with single SnS 2 , 3% Ti 3 C 2 /SnS 2 displayed the better performance, the removal rate of TC-HCL reached 87.7% and the kinetic rate constant (k) of the optimal 3% Ti 3 C 2 /SnS 2 composite was about 2.7 times of that of bare SnS 2 . The improved photocatalytic activity of Ti 3 C 2 /SnS 2 is ascribed to the formation of 2D/2D Schottky heterojunction, which promotes the spatial charge separation and increases the surface reactive sites., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Polycyclic aromatic hydrocarbons (PAHs) are widespread toxic pollutants in the atmosphere and have attracted much attention for decades. In this study, we compared the health risks of PAHs based on different toxic equivalent factors (TEFs) in a heavily polluted area during heating and non-heating periods. We also pay attention to occupancy probability (OP) in different polluted areas. The results showed that there were big differences for calculations by different TEFs, and also by OP or not. Age groups except adults were all lower calculated by OP than not. The sensitivity analysis results on the incremental lifetime cancer risks (ILCR) for population groups by Monte Carlo simulation identified that the cancer slope factor extremely affected the health risk assessment in heating periods, followed by daily inhalation exposure levels. However, daily inhalation exposure levels have dominated the effect on the inhalation ILCR and then followed by the cancer slope factor in non-heating periods. The big differences by different calculations investigated that it is important to set up the correlations between the pollution level and health risks, especially for the longtime health assessment., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

As an important central city in western China, Xi'an has the worst atmospheric pollution record in China and many measures have been taken to improve the air quality in the past few years. In this study, PM 2.5 samples were collected across four seasons from 2017 to 2018 in Xi'an. Organic carbon and elemental carbon, water soluble ions, and elements were monitored to assess the air quality. The average annual PM 2.5 concentration was (134.9 ± 48.1 μg/m 3 ), with the highest concentration in winter (188.8 ± 93.2 μg/m 3 ), and lowest concentration in summer (71.2 ± 12.1 μg/m 3 ). The secondary generation of sulfate (SO 4 2- ) and nitrate (NO 3 - ) was strong in spring, and secondary organic carbon (SOC) was formed in all seasons. The compositions of PM 2.5 changed greatly during a sandstorm occurred and the Spring Festival. The sandstorm played a positive role in removing local pollutant NO 3 - , but also increased the concentration of SO 4 2- , however both the concentration of SO 4 2- and NO 3 - greatly increased by secondary generation during Spring Festival. Potential source analysis showed that during the sandstorm, pollutants were transported over a long distance from the northwest of China, whereas it was mainly from the local and surrounded emissions during the Spring Festival. Except Ca 2+ and geological dust (GM), the other components in PM 2.5 increased significantly on the day of the Spring Festival. During sampling time in Xi'an, the positive matrix factorization (PMF) model analysis showed that PM 2.5 mainly came from vehicle emission, coal combustion, and biomass burning., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Reliable packaging for implantable neural prosthetic devices in body fluids is a long-standing challenge for devices' chronic applications. This work studied the stability of Parylene C (PA), SiO 2 , and Si 3 N 4 packages and coating strategies on tungsten wires using accelerated, reactive aging tests in three solutions: pH 7.4 phosphate-buffered saline (PBS), PBS + 30 mM H 2 O 2 , and PBS + 150 mM H 2 O 2 . Different combinations of coating thicknesses and deposition methods were studied at various testing temperatures. Analysis of the preliminary data shows that the pinholes/defects, cracks, and interface delamination are the main attributes of metal erosion and degradation in reactive aging solutions. Failure at the interface of package and metal is the dominating factor in the wire samples with open tips.

Hydrogen sulfide (H2S) is an important signalling molecule with multiple biological functions. The reported H2S fluorescent probes are majorly based on redox or nucleophilic reactions. The combination usage of both redox and nucleophilic reactions could improve the probe's selectivity, sensitivity and stability. Herein we report a new dual-reactable probe with yellow turn-on fluorescence for H2S detection. The sensing mechanism of the dual-reactable probe was based on thiolysis of NBD (7-nitro-1,2,3-benzoxadiazole) amine (a nucleophilic reaction) and reduction of azide to amine (a redox reaction). Compared with its corresponding single-reactable probes, the dual-reactable probe has higher selectivity and fluorescence turn-on fold with magnitude of multiplication from that of each single-reactable probe. The highly selective and sensitive properties enabled the dual-reactable probe as a useful tool for efficiently sensing H2S in aqueous buffer and in living cells.

RNA interference (RNAi) is a cellular process for gene silencing. Because of poor serum stability, transferring dsRNA directly into the target cells is a challenge. We report a facile and universal strategy to construct short hairpin RNA (shRNA) transcription nanoparticles with multiple shRNA transcription templates by PCR with flexible branched primers (branch-PCR). Compared with conventional linear shRNA transcription templates, these shRNA transcription nanoparticles show excellent stability against digestion by exonuclease III. Importantly, we found that our highly stable shRNA transcription nanoparticles can also be transcribed and thus induce efficient and long-lasting RNAi with picomolar activity in living mammalian cells. These chemically well-defined branch-PCR-generated stable shRNA transcription nanoparticles might facilitate RNAi delivery with a long-lasting RNAi effects., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hydrogen sulfide (H2 S) is an important endogenous signaling molecule with multiple biological functions. New selective fluorescent turn-on probes based on fast thiolyling of NBD (7-nitro-1,2,3-benzoxadiazole) amine were explored for sensing H2 S in aqueous buffer and in living cells. The syntheses of both probes are simple and quite straightforward. The probes are highly sensitive and selective toward H2 S over other biologically relevant species. The fluorescein-NBD-based probe showed 65-fold green fluorescent increase upon H2 S activation. The rhodamine-NBD-based probe reacted rapidly with H2 S (t1/2 ≈1 min) to give a 4.5-fold increase in red fluorescence. Moreover, both probes were successfully used for monitoring H2 S in living cells and in mice. Based on such probe-based tools, we could observe H2 O2 -induced H2 S biogenesis in a concentration-dependent and time-dependent fashion in living cells., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hydrogen sulfide (H2 S) is an important endogenous signaling molecule with a variety of biological functions. Development of fluorescent probes for highly selective and sensitive detection of H2 S is necessary. We show here that dual-reactable fluorescent H2 S probes could react with higher selectivity than single-reactable probes. One of the dual-reactable probes gives more than 4000-fold turn-on response when reacting with H2 S, the largest response among fluorescent H2 S probes reported thus far. In addition, the probe could be used for high-throughput enzymatic assays and for the detection of Cys-induced H2 S in cells and in zebrafish. These dual-reactable probes hold potential for highly selective and sensitive detection of H2 S in biological systems., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The two signaling molecules H2 S and H2 O2 play key roles in maintaining intracellular redox homeostasis. The biological relationship between H2 O2 and H2 S remains largely unknown in redox biology. In this study, we rationally designed and synthesized single- and dual-response fluorescent probes for detecting both H2 O2 and H2 S in living cells. The dual-response probe was shown to be capable of mono- and dual-detection of H2 O2 and H2 S selectively and sensitively. Detailed bioimaging studies based on the probes revealed that both exogenous and endogenous H2 O2 could induce H2 S biogenesis in living cells. By using gene-knockdown techniques with bioimaging, the H2 S biogenesis was found to be majorly cystathionine β-synthase (CBS)-dependent. Our finding shows the first direct evidence on the biological communication between H2 O2 (ROS) and H2 S (RSS) in vivo., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Flexible branched primers were designed to construct stable gene nanoparticles with multiple target gene copies through polymerase chain reaction, which can be used as an efficient transcription template in eukaryotic cells for gene delivery.

A FRET-ICT dual-quenching probe with large off-on fluorescent response upon H2S treatment is reported. The probe can be used for bioimaging of endogenous H2S in living cells.

Hydrogen sulfide (H2S) is an endogenously produced gaseous signaling molecule with multiple biological functions. To visualize the endogenous in situ production of H2S in real time, new coumarin- and boron-dipyrromethene-based fluorescent turn-on probes were developed for fast sensing of H2S in aqueous buffer and in living cells. Introduction of a fluoro group in the ortho position of the aromatic azide can lead to a greater than twofold increase in the rate of reaction with H2S. On the basis of o-fluorinated aromatic azides, fluorescent probes with high sensitivity and selectivity toward H2S over other biologically relevant species were designed and synthesized. The probes can be used to in situ to visualize exogenous H2S and D-cysteine-dependent endogenously produced H2S in living cells, which makes them promising tools for potential applications in H2S biology., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)