Multi‐Hydration Induced Zwitterionic Hydrogel with Open Environment Stability for Chemical Sensing

Abstract Hydrogels with open environment stability are of great significance in the fields of microelectronics, organ regeneration, and hydrogel‐based sensors. Although a series of strategies for exploring highly robust hydrogels have been proposed, it is still challenging to improve environmental stability while maintaining the original dispersed medium feature. Here, 1‐vinyl‐3‐butylimidazolium (VBIM) and acrylic acid (AA) are used as the anionic and cationic monomers to prepare zwitterionic hydrogels through the thermal initiation polymerization. The prepared PAA‐IL (polyacrylic acid‐co‐ionic liquid) hydrogel forms a large number of multi‐hydration, including hydrogen bonds and ion‐dipole interactions with water to inhibit the freezing and volatilization of water, and it possesses good structural stability due to the formation of ion bond self‐association through interchain charge interaction. The robust stability of the chemical sensor with PAA‐IL hydrogels as the substrate at different pH and temperature verifies the validity of the proposed design strategy. It is expected that the present zwitterionic hydrogel design strategy would shine a light on the exploration of environment‐stable hydrogels and hydrogel‐based chemical sensors

Zn-doped SnO2 nanocrystals as efficient DSSC photoanode material and remarkable photocurrent enhancement by interface modification

Zn-doped SnO2 nanocrystals with different doping concentrations were synthesized and the nanocrystal photoanode based DSSC achieved a PCE of 2.07% with a high Voc (0.67 V). TiCl4 modification of the photoanode greatly improves the charge injection efficiency and charge collection efficiency and the resulting PCE increased to 4.32% despite a decreased dye adsorption. The Zn-doped SnO2 nanocrystals will be of particular interest as photoanode material in DSSCs.Published versio

Design of Highly Efficient Electronic Energy Transfer in Functionalized Quantum Dots Driven Specifically by Ethylenediamine

The exploration of emerging functionalized quantum dots (QDs) through modulating the effective interaction between the sensing element and target analyte is of great significance for high-performance trace sensing. Here, the chromone-based ligand grafted QDs (QDs-Chromone) were initiated to realize the electronic energy transfer (EET) driven specifically by ethylenediamine (EDA) in the absence of spectral overlap. The fluorescent and colorimetric dual-mode responses (from red to blue and from colorless to yellow, respectively) resulting from the expanded conjugated ligands reinforced the analytical selectivity, endowing an ultrasensitive and specific response to submicromolar-liquid of EDA. In addition, a QDs-Chromone-based sensing chip was constructed to achieve the ultrasensitive recognition of EDA vapor with a naked-eye observed response at a concentration as low as 10 ppm, as well as a robust anti-interfering ability in complicated scenarios monitoring. We expect the proposed EET strategy in shaping functionalized QDs for high-performance sensing will shine light on both rational probe design methodology and deep sensing mechanism exploration

Intermolecular through‐space charge transfer enabled by bicomponent assembly for ultrasensitive detection of synthetic cannabinoid JWH‐018

Abstract Launching the intermolecular through‐space charge transfer (TSCT) from a bicomponent assembly for photophysical property manipulation is of great significance in fluorescence probe design. Here, we demonstrate the elaborate control of droplet evaporation dynamics for intermolecular TSCT can facilitate the ultrasensitive detection of JWH‐018, a representative synthetic cannabinoid. Driven by diverse intermolecular interactions, the probe, and JWH‐018 assemble in a closely stacked manner to emit strong fluorescence at 477 nm, ascribing to the intermolecular TSCT at the S2 state. The strategy realizes an ultra‐low limit of detection of 11 nmol/mL and great selectivity towards JWH‐018. The practicability is further verified by constructing a sensing chip for JWH‐018 aerosol detection, which facilitates the on‐site drug abuser screening with the naked eye. Moreover, the proposed assembly‐enabled TSCT is expected to find a variety of applications for optoelectronic materials design and photophysical mechanism‐dominated molecular recognition

Additional file 1: Figure S1. of Sensitive, Selective, and Fast Detection of ppb-Level H2S Gas Boosted by ZnO-CuO Mesocrystal

XRD patterns of the products obtained from zinc nitrate and copper nitrate as the mixed precursor by annealing at 200 and 250 °C. Figure S2. Dynamic response curves of the ZnO-CuO mesocrystal-based sensor responding to 1000 ppm NO2, H2, CO2, CO, acetone and NH3 at 125 °C. Figure S3. The responses of the ZnO-CuO mesocrystal based sensor upon exposure to air with different relative humidity relative to air with RH of 20 % at 125 °C. (DOCX 198 kb

Gas Adsorption Thermodynamics Deduced from the Electrical Responses in Gas-Gated Field-Effect Nanosensors

Understanding the underlying physical chemistry governing the nanomaterial-based electrical gas sensing process is pivotal for the rational design of high-performance gas sensors. Herein, using a remarkable ppb-level NO₂-gated field-effect nanosensor that is based on a reduced graphene oxide rGO/TiO₂ nanoparticle heterojunction, as an exploratory platform, we have established a generic physical chemistry model to quantitatively gain insight into the correlation between the measured source-drain (S-D) current and the gas sorption thermodynamics in this NO₂ nanosensor. Based on thin-film field-effect transistor theory, the measured S-D current leads to the solution to the gas-induced gate voltage, which further solves the surface charge density using the Graham surface potential vs surface charge density function. Consequently, based on the Van’t Hoff equation, key thermodynamic information can be obtained from this model including adsorption equilibrium constants and adsorption enthalpy of NO₂ on TiO₂ nanoparticles. The acquisition of gas adsorption enthalpy provides a generic and nonspecific method to identify the nature of the adsorbed molecules