Search

Human epidermal growth factor receptor 2 (HER2) is an important breast cancer marker that is abnormally expressed in 20–30% of breast cancer patients. Here, we report an electrochemical biosensor using carboxy-functionalized multi-walled carbon nanotubes (MWCNTs) and activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) on a highly conductive poly (3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) platform for efficient detection of HER2. In this work, PEDOT:PSS and AuNPs were first modified onto a glassy carbon electrode (GCE) to increase the signal transmission efficiency of the biosensor. Then, an aptamer-HER2-antibody (Apt-HER2-Ab*) sandwich structure was constructed to capture and immobilize the target HER2. Of note, the Ab* is a composite composed of Ab, poly ferrocene methyl methacrylate (PFMMA), and carboxyl-functionalized MWCNTs (Ab-MWCNTs-PFMMA). The BMP was attached to the electrode by forming an ester bond with the hydroxyl group on the carboxyl-functionalized MWCNTs, and triggering ARGET ATRP to attach FMMA to the MWCNTs. In addition, Ab was attached to the electrode by ester bonds with the MWCNTs. In the presence of highly conductive materials and a polymer, the biosensor showed high sensitivity and a good linear relationship between the current signal and HER2 concentration in the range of 10−2 to 103 ng mL−1, and the limit of detection (LOD) was 1.979 fg mL−1. The regression equation was I (μA) = 8.23905 lg[CHER2/ng mL−1] + 25.3585 (R2 = 0.995). Moreover, the biosensor still shows good detection performance in the complex environment of normal serum, which is promising for clinical applications. [ABSTRACT FROM AUTHOR]

Classical local anesthetics are unsuitable to treat regional pain lasting several days due to their limited duration and systemic toxicity. Self-delivery nano systems without excipients were designed for long-term sensory blocks. 1a self-assembled into different vehicles with different fractions of intermolecular π–π stacking, transported itself into nerve cells, and released single molecules slowly to achieve long-term duration for rats' sciatic nerve block for 11.6 h in water, 12.1 h in water with CO2 and 3.4 h in NS (normal saline). After the counter ions were changed to SO42−, 1e can self-assemble into vesicles and prolong the duration to 43.2 h, which was much longer than the 3.8 h led by (s)-bupivacaine hydrocloride (0.75%). This was mainly caused by the enhancement of self-release and counter ion exchange inside nerve cells, which were affected by the gemini surfactant structure, pKa of the counter ions and π–π stacking interactions. [ABSTRACT FROM AUTHOR]

Surface passivation by organic dyes has been an effective strategy for simultaneous enhancement of the efficiency and stability of perovskite solar cells. However, lack of in-depth understanding of how subtle structural changes in dyes leads to distinctly different passivation effects is a challenge for screening effective passivation molecules (PMs). In an experiment done by Han et al. (Adv. Energy Mater., 2019, 9, 1803766), three donor–π–acceptor (D–π–A) dyes (SP1, SP2, and SP3) with distinct electron donors have been applied to passivate the perovskite surface, where the efficiency and stability of PSCs are quite different. Herein, we carried out first-principles calculations and ab initio molecular dynamics (AIMD) simulations on the structures and electronic properties of SP1, SP2, SP3, and their passivated perovskite surfaces. Our results showed that SP3 enhances the carrier transfer rate, electric field, and absorption region compared to SP1 and SP2. Moreover, AIMD simulations reveal that the cooperative multiple interactions of O–Pb, S–Pb, and H–I between SP3 and the perovskite surface result in a stronger passivation effect in a humid environment than that of SP1 and SP2. This work is expected to pave the way for screening dye passivation molecules to endow perovskite solar cells with high efficiency and stability. [ABSTRACT FROM AUTHOR]

Lidocaine salts self-assembled into different nano systems in water at a clinical dosage (2%, 0.2 mL) without excipient addition, and led to different sensory block durations and acute systemic toxicities, which were affected by the self-delivery and self-release behaviors of the salts in vivo. These differences were mainly caused by intermolecular π–π stacking under different conditions, which was proved by the unique supramolecular arrangement of gourd-shaped Janus particles. π–π stacking in lidocaine nano systems can be enhanced by carbon dioxide addition or the exchange of counter ions from Br− to Cl−. Without π–π stacking, nano systems self-assembled by lidocaine hydrobromide achieved 7.8 h sensory block by intradermal administration on rats, which is much longer than the efficacy of classical local anesthetics and more suitable for postoperative treatment. [ABSTRACT FROM AUTHOR]

In this paper, vanadium carbides VC2 and bi-transition-metal carbides V1/2Mn1/2C2 are predicted to be stable metallic nanosheets showing promising mechanical properties and their Young's moduli are 70.8 N m−1 and 83.7 N m−1, respectively. Ab initio molecular dynamics results showed that both VC2 and V1/2Mn1/2C2 can tolerate temperatures up to 1000 K showing favorable thermal properties. The excellent Li-ion specific energy storage capacity and low diffusion barrier also make them promising candidates as anode materials. In addition, nonmagnetic–ferromagnetic (–ferrimagnetic) transitions in VC2 and V1/2Mn1/2C2 can be tuned easily by oxygen or fluorine passivation. [ABSTRACT FROM AUTHOR]

A series of atypical asymmetric gemini surfactants with an amphiphilic carbonate group (–O–CO–O–) have been prepared. Some of these compounds could self-assemble in water into gourd-shaped Janus particles (JPs). Initial results suggested that the formation of JPs was highly likely to be related to their atypical gemini surfactant structure. To our knowledge, this is the first report on JPs that are self-assembled from a single kind of small organic molecule. We believe that our results will be utilized in many fields. [ABSTRACT FROM AUTHOR]

Two novel organic sensitizers (FNE55 and FNE56) containing a 6,7-difluoroquinoxaline moiety have been designed and synthesized for quasi-solid-state dye-sensitized solar cells (DSSCs). For comparison, an organic dye, FNE54, without fluorine has also been synthesized. The effects of the introduction of fluorine on the absorption, electrochemical and photovoltaic properties have been systematically investigated. Upon the incorporation of fluorine in the quinoxaline unit, the electron-withdrawing ability is strengthened, which results in the enhanced push–pull interactions and thus narrows the energy band gap. The absorption maximum wavelength in toluene solution bathochromically shifts from 504 nm for FNE54 to 511 nm for FNE55, and further to 525 nm for FNE56. However, although the lowest unoccupied molecular orbitals (LUMOs) are lowered down after the introduction of fluorines, the driving force for the photo-excited electrons from their excited states to the semiconductor conduction band is still sufficient. Consequently, the quasi-solid-state DSSC based on FNE56 exhibits a highest power conversion efficiency of 8.2%, which is 37% higher than that for FNE54 based quasi-solid-state DSSCs. [ABSTRACT FROM AUTHOR]

In this paper, vanadium carbides VC 2 and bi-transition-metal carbides V 1/2 Mn 1/2 C 2 are predicted to be stable metallic nanosheets showing promising mechanical properties and their Young's moduli are 70.8 N m -1 and 83.7 N m -1 , respectively. Ab initio molecular dynamics results showed that both VC 2 and V 1/2 Mn 1/2 C 2 can tolerate temperatures up to 1000 K showing favorable thermal properties. The excellent Li-ion specific energy storage capacity and low diffusion barrier also make them promising candidates as anode materials. In addition, nonmagnetic-ferromagnetic (-ferrimagnetic) transitions in VC 2 and V 1/2 Mn 1/2 C 2 can be tuned easily by oxygen or fluorine passivation.