Detection of Fe 3+ ions is of paramount importance for environmental protection and human health. Herein, we reported a highly selective and sensitive fluorescence probe for the quantification of Fe 3+ ions in aqueous solution with Eu 3+ /SnO 2 nanocrystals co-doped silica glasses as the sensing unit. Due to the high stability of silica glasses and their efficient protection for emitting centers, the probe has good recyclability and can be applied in real water environment, indicating its potential for on-site sensing. The detection limit of Fe 3+ ions is 7.54 nmol/L. Experiments were carried out to verify that the probe shows excellent cross interference with other metal ions. The detecting mechanism can be ascribed to the excitation/emission absorption and energy transfer of Fe 3+ ions. Our work paves a novel way of semiconductor oxide nanocrystals for applications in optoelectronics .
Dodecahedron-like SnO 2 nanomaterial was synthesized via a solvothermal method under mild reaction condition. The morphological and structural characterization results indicated that the as-prepare dodecahedral SnO 2 nanocrystallines with the average length of 130 nm and width of 45 nm were partially surrounded by high surface-energy {221} facets. The gas-sensing performance of the sample was investigated and the experiment results showed that the sensor had a good sensitivity to sulfur dioxide (SO 2 ) at 183 °C. To 800 ppb SO 2 , the response could reach 1.32 and the response time was about 10 s. The good SO 2 -sensing performance of SnO 2 nanocrystallines was closely related to the high surface-energy {221} facets whose surface possessed more dangling bonds and the corresponding SO 2 -sensing mechanism was discussed.
The bilayered electron transport layer (ETL) has made significant contributions to enhancing the photovoltaic performance for perovskite solar cells. However, it is generally required to prepare the TiO 2 at a high temperature before adding the SnO 2 layer due to the difference in temperature tolerance, resulting in energy consumption and hampering electron transfer. To address this issue, we proposed a simple low-temperature process based on TiO 2 @SnO 2 nanocrystals for bilayered ETL. The introduction of SnO 2 enhances the Fermi level and lowers the valence band position of TiO 2 nanocrystals, which facilitates electron extraction and hole blocking, leading to the enhancement of open circuit voltage and fill factor. Additionally, TiO 2 @SnO 2 nanocrystals provide a more suitable refractive index and less parasitic absorption than TiO 2 , these optical gains forming a higher short-circuit current. As a result, the champion efficiency of the perovskite solar cell was significantly raised from 16.17% to 19.04% along with enhancement in the stability and hysteresis phenomena. Moreover, photovoltaic performance can be further increased by combining perovskite component engineering and interfacial passivation because of the high compatibility of TiO 2 @SnO 2 ETL.
Acetamiprid is a kind of broad-spectrum pesticides that has been largely applied in agriculture and household pest control. In this paper, a simple, novel and highly sensitive electrochemiluminescence aptamer sensor (ECL aptasensor) based on Ag 3 PO 4 -NH 2 -SnO 2 was proposed. The ECL signal was greatly amplified with the synergistic effect of Ag 3 PO 4 and NH 2 -SnO 2 (Ag 3 PO 4 -NH 2 -SnO 2 ) which was dropped on a glass carbon electrode (GCE) and used as working electrode. We designed an “on–off” ECL sensing strategy for the sensitive and specific detection of acetamiprid. Under the optimal conditions, the linear range of the sensor for acetamiprid detection was 1.0 × 10 −11 ∼ 1.0 × 10 −5 M, with a detection limit of 2.5 × 10 −12 M (S/N = 3). The method showed simple and fast operation, high sensitivity and selectivity, strong anti-interference ability and good stability. More importantly, the developed aptasensor exhibited excellent recognition ability towards residual acetamiprid in actual water samples, which might open promising avenues to develop new ECL systems for biological analysis and environmental water monitoring.
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