We report cellphone-based detection of dopamine with attomolar sensitivity in clinical samples with the use of a surface plasmon-coupled emission (SPCE) platform. To this end, silver-coated carbon nanotubes were used as spacer and cavity materials on SPCE substrates to obtain up to 100-fold fluorescence enhancements. The presence of silver on the carbon nanotubes helped to overcome fluorescence quenching arising due to π-π interactions between the carbon nanotube and rhodamine 6G. The competing adsorption of dopamine versus rhodamine 6G on graphene oxide was utilized to develop this sensing platform.

An allylimidazolium-based poly(ionic liquid), poly-[vinylbenzylallylimidazolium bis(trifluoromethane)sulfonylimide] (PVBCAImTFSI) was used as a binder for graphite anodes in lithium-ion batteries. The anodes with the synthesized binder exhibited lesser electrolyte degradation and higher lithium-ion diffusion. Electrochemical impedance spectroscopy (EIS) results showed decreased interfacial and diffusion resistance for PVBCAImTFSI-based electrodes after cycling compared to PVDF-based anodes. Dynamic electrochemical impedance spectroscopy (DEIS) results indicated the interfacial resistance of the interface formed for the PVBCAImTFSI-based anodes to be 3 times lesser than the PVDF-based anodes. Suppression of electrolyte degradation and decrease in the intercalation− deintercalation potential and improved Li-ion diffusion coefficient for PVBCAImTFSI-based half-cells were observed from cyclic voltammetry measurements. DFT-based theoretical studies also speculated the suppression in the electrolyte degradation in the case of PVBCAImTFSI binder due to the positioning of its HOMO−LUMO levels. A reversible discharge capacity of 210 mAh/g was obtained for PVBCAImTFSI-based half-cells at 1C rate as compared to the 140 mAh/g obtained for PVDF-based anodic half-cells. After 500 cycles, 95% retention in the discharge capacity was observed. Also, PVBCAImTFSI-based anodes exhibited better charge− discharge stability than the PVDF-based anodes. Suppression of electrolyte degradation, reduction in the interfacial resistance, enhanced wettability, and an optimal SEI layer formed in the case of PVBCAImTFSI-based anodes cumulatively led to an enhanced stability and cyclability during the charge−discharge studies as compared to the commercially employed PVDF-based anodes. Thus, the tuning of the interfacial properties leads to the improvement in the performance of the lithium-ion batteries with PVBCAImTFSI as a binder.

In this work, we demonstrate for the first time the ultrasensitive detection of Hg2+ ions with femtomolar sensitivity in water samples with the use of the surface plasmoncoupled emission (SPCE) platform. The use of portable network diagnostic tools for water security and integrated water shed management is a topic of recent research interest. In this context, the current study explores Hg2+ monitoring using a rhodamine-6G (Rh6G) derivative bearing a monothiospirolactone mounted onto a SPCE substrate. Thus far, the limit of detection for mercury ions by the conventional fluorescence technique has been 0.15 nM. However, we have achieved 1 fM Hg2+ detection using silver nanoparticle-based spacer layer engineering on an SPCE sensor chip. Using this technology, a field device can be fabricated for rapid, ultrasensitive, multianalyte detection (of contaminants) in water samples.Keywords: fluorescence enhancements; mercury sensing; silver nanoparticles ; spacer engineering; surface plasmon-coupled emission Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.

Solid electrolyte interphase (SEI) formation in Li-ion batteries is essential for good long-term performance of the cell. However, for electrodes exhibiting high volume expansion (like Si and Sn), continuous SEI formation can not only deplete electrolyte content but also increase cell impedance and hence mediocre performance. This is particularly detrimental in the case of thin-film electrodes where there is a minute amount of active materials loading. In the current work, defined poly­(borosiloxane) (PBS) as an artificial polymeric SEI having self-healing, anion-trapping properties, and electron-deficient boron moiety is investigated. Studies on thin-film Si electrodes show excellent enhancement with polymeric coating in terms of cycling stability. These improvements are attributed to a combination of factors including the anion-trapping effect of tricoordinate boron, self-healing ability of PBS, and adherence to the electrode surface.

Lithium sulfur (Li–S) battery is an appealing energy storage system due to its high theoretical specific capacity and specific energy. However, two main challenges, lithium polysulfides (LPS) dissolution from the sulfur cathode and the unstable Li anode, impede the practical application of Li–S battery. Developing advanced electrolyte is an effective strategy to tune the stability of both sulfur cathode and Li anode. Here, a concentrated imidazolium-based ionic liquids (IL) electrolyte was explored for Li–S battery with the synergistic advantages of both IL and high concentrated electrolyte. A systematic study was conducted to reveal the effect of salt concentration on the properties of the IL electrolyte and the electrochemical performances of Li–S battery. It is found that an effective suppression of LPS dissolution and improved stability of Li anode can be obtained with increase of salt concentration. As a result, a good cycling stability of the Li–S battery is achieved in the concentrated IL electrolyte, with high capacity retention of 92% after 100 cycles at current density of 0.1 C. The concentrated electrolyte based on IL solvent exhibits good compatibility with both cathode and anode, offering a new opportunity for designing electrolyte to achieve stable electrochemical system.