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It remains a great challenge to develop effective strategies for improving the weak cathodic electrogenerated chemiluminescence (ECL) of the luminol-dissolved O 2 system. Interface modulation between metal and supports is an attractive strategy to improve oxygen reduction reaction (ORR) activity. Therefore, the design of electrocatalysts via interface modulation would provide new opportunities for the ECL amplification involving reactive oxygen species (ROSs). Herein, we have fabricated an Ag single-atom catalyst with an oxygen-bridged interface (Ag-O-Co) through the electrodeposition of Ag on a CoAl layered double hydroxide (LDH) modified indium tin oxide (ITO) electrode (Ag s /LDH/ITO). Interestingly, it was found that the cathodic ECL intensity of the luminol-dissolved O 2 system at the Ag s /LDH/ITO electrode was extraordinarily enhanced in comparison with those at bare ITO and other Ag nanoparticle-based electrodes. The enhanced ECL performances of the Ag s /LDH/ITO electrode were attributed to the increasing amounts of ROSs by electrocatalytic ORR in the Ag-O-Co interface. The electron redistribution of Ag and Co bimetallic sites could accelerate electron transfer, promote the adsorption of O 2 , and sufficiently activate O 2 through a four-electron reaction pathway. Finally, the luminol cathodic ECL intensity was greatly improved. Our findings can provide inspiration for revealing the interface effects between metal and supports, and open up a new avenue to improve the luminol cathodic ECL.

Oxygen vacancy is known to act as a reactive center in oxides to produce radicals. Currently, X-ray photoelectron spectra (XPS) become a unique spectral tool for analyzing oxygen vacancy based on the differences in atomic number ratios between metal ions and lattice oxygen. In this work, it was found that the superoxide radical (O 2 •- )-luminol electrochemiluminescence (ECL) intensity linearly increases with increasing the oxygen vacancy concentrations of TiO 2 samples coated on the electrodes. An experimental study of the mechanism demonstrates that an increase in oxygen vacancy concentrations could lead to an increase in the generation of O 2 •- , resulting in an increase in the O 2 •- -related luminol ECL signals. Accordingly, we have developed a rapid and simple O 2 •- -luminol ECL platform to detect oxygen vacancy in TiO 2 samples, based on the relationship between O 2 •- generation and oxygen vacancy. The proposed ECL platform exhibits good reproducibility and stability through the parallel ECL measurements. Moreover, the feasibility is verified by analyzing the oxygen vacancy concentrations in different TiO 2 samples with varying the Co, Cr, Fe, and N doping concentrations. The oxygen vacancy concentrations obtained by the proposed ECL method could match well with those obtained by conventional XPS measurements. Our successful construction of the ECL platform will significantly promote the development of the oxygen vacancy detection in oxides and deepen the understanding of the relationship between oxygen vacancy and radicals.

It is a considerable challenge to realize 3D fluorescence quantification of macrodispersion of clay fillers in a polymer matrix mainly owing to quenching of light emission in the solid state. Herein, a strong light emission is generated within the interlaminated clay as a result of a cation-π interaction between cationic surfactant and fluorescent polycyclic aromatic hydrocarbon when they are cointercalated into clay. Confocal laser scanning microscopy (CLSM) is applied for 3D imaging of macrodispersion of the fluorescence-labeled clay fillers in a silicone rubber matrix. More importantly, the quantification of macrodispersion of clay fillers in the overall polymer composite is established by a statistical model. The proposed method fills in an important gap in the standard for macrodispersion quantification of inorganic fillers in polymer composites.

Finding an efficient photosensitizer is crucial in ensuring a therapeutic effect of photodynamic treatment. Currently, screening of photosensitizers during photodynamic therapy is achieved by evaluating the total yield of singlet oxygen ( 1 O 2 ), rather than monitoring the formation dynamics of 1 O 2 . 1 O 2 -based chemiluminescence (CL) is a suitable method to directly monitor the generated amount of 1 O 2 . Herein, the tetraphenylethene-sodium dodecyl sulfonate surfactant with aggregation-induced emission characteristics can remarkably amplify the intrinsic CL emission from 1 O 2 by integrating its micellar microenvironment with a CL energy acceptor effect in a cage-like structure. We present a new luminescence platform for the rapid screening of photosensitizers by monitoring the formation dynamics of 1 O 2 during photodynamic therapy. This study will not only be critical in optimizing the irradiation time during photodynamic therapy but also open a new door to the discovery of efficient photosensitizers.