A novel bifunctional thiophene-based Schiff base TS as a colorimetric and fluorescent turn-on sensor for rapid and simultaneous detection of Al 3+ and Zn 2+ ions with high selectivity and sensitivity has been developed. The sensor shows remarkable fluorescence enhancement response for Al 3+ and Zn 2+ over a broad pH range with good anti-interference capability, which accompanied with an obvious color change easily detected by naked eyes. Sensor TS can detect as low as 3.7 × 10 −9 M for Al 3+ and 3.0 × 10 −8 M for Zn 2+ , whereas respective association constants are 1.16 × 10 4 M −1 and 2.08 × 10 4 M −1 . With the help of fluorescence titration and Job's plot, the stoichiometric ratio of TS with Al 3+ /Zn 2+ was determined to be 1:1. The sensing mechanism of sensor TS with Al 3+ /Zn 2+ based on the chelation-enhanced fluorescence (CHEF) was analyzed in detail through 1 H NMR titration, FTIR, HRMS and DFT studies . Moreover, sensor TS has been applied to the detection of Al 3+ and Zn 2+ in real environmental water and food samples as well as the filter paper-based test strips. Furthermore, sensor TS has good cell-permeability and can be used to selectively sense intracellular Al 3+ and Zn 2+ by bioimaging.
Wanqing Qian,Yan Shu,Cai Pan,Xueqing Yu,Weitao Su,Mikhail P. Kuz'min,Kaixin Song
Near-infrared phosphor conversion light emitting diode (NIR pc-LED) has important application value in plant growth, night vision imaging and biological detection. Its performance depends on the optimized design of fluorescent materials. Based on gadolinium gallium garnet (Gd 3 Ga 5 O 12 ), the near-infrared phosphors of Gd 2.5 (CaSn) 0.5 (InAl) 0.5 Ga 3.5-x O 12 : xCr 3+ (x = 0.01–0.09) were prepared by Ca 2+ -Sn 4+ /In 3+ -Al 3+ double ion pair synergistic substitution strategy. Under excitation of 450 nm blue light, the material exhibits broadband near-infrared emission covering the range of 650–1150 nm, with a quantum yield of 96.29 %. The material exhibits excellent thermal stability of luminescence and can maintain 82.4 % of the initial emission intensity at room temperature at 423K. The NIR pc-LED device based on this phosphor package achieved 67.37 mW output power and 16.68 % photoelectric conversion efficiency at 100 mA driving current. Application verification shows that the NIR pc-LED light source shows excellent performance in plant supplementary light, night vision security, information encryption and nondestructive testing applications. It fully proves that the broadband near-infrared emission of this series of phosphors can take into account multi-functional application scenarios and has broad development prospects.
Hongyan Yin,Lizhi Chen,Fangfei Liu,Tursun Abdiryim,Jiaying Chen,Xinyu Jing,Yancai Li,Mengyao Su,Xiong Liu
MXene-based conductive hydrogels have emerged as a new type of soft materials in flexible electronics. Herein, metal coordination is introduced into MXene-based conductive hydrogels to synchronously enhance the mechanical and self-healing properties. MXene-based conductive hydrogels are made up of polyacrylic acid (PAA), sium carboxymethyl cellulose (SCMC), Ti 3 C 2 T X and metal ions (Ni 2+ , Al 3+ or Sn 4+ ). PAA/SCMC/Ti 3 C 2 T X /Sn 4+ hydrogel is found to have excellent mechanical (stress: 122 kPa; strain: 1688 %; toughness: 0.95 ± 0.12 MJ m −3 ) and self-healing (self-healing efficiency: 99.27 % (conductivity); 81.16 % (stress); and 83.13 % (strain)) properties due to the metal coordination and H-bonding. The hydrogel has also good conductivity of 0.82 S m −1 and adhesion of 38.94 kPa. The flexible sensors based on this hydrogel can efficiently detect human motions, electromyography (EMG), electrocardiography (ECG) and handwriting signals. Furthermore, a supercapacitor assembled from this hydrogel has a high specific capacitance of 118.66 F g −1 and good stability (15000 charge-discharge cycles). This work provides an effective strategy for exploiting mechanically tough and self-healing MXene-based conductive hydrogels with prospective applications in flexible electronics.
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