This work presents a thorough guide to procedures for absolute electrochemiluminescence (ECL) quantum efficiency (ΦECL) measurements, which if employed effectively should raise the research impact of ECL studies for any luminophore. Absolute measurements are not currently employed in ECL research. Instead, ECL efficiencies have been determined relative to Ru­(bpy)3 2+ under similar conditions, regardless of whether the conditions are favorable for Ru­(bpy)3 2+ emissions or not. In fact, the most cited Ru­(bpy)3 2+ ΦECL is from the pioneering work by the Bard research group in 1973 by means of a rotating ring-disk electrode revolving at 52 rotations per second measured with a silicon photodiode. Our presented technique uses a common disk electrode, spectrometer, and photomultiplier tube to measure the ΦECL. The more common light detection hardware and electrodes combined with an in-depth calculation walkthrough will provide ECL researchers the necessary tools to implement ΦECL measurement procedures in their own laboratories. Following a facile instrument setup and calculation, a systematic study of Ru­(bpy)3 2+ ΦECL finds comparable results to those performed by Bard and co-workers.

In this work, using a photon-counting device, we outline our physical strategy to determine absolute electrochemiluminescence (or electrogenerated chemiluminescence, ECL) quantum efficiencies of coreactant systems in comparison with those in annihilation pathways. This absolute method addresses many of the issues with existing relative ECL efficiency measurements, including inconsistencies stemming from nonstandardized experimental conditions and incompatible luminophore systems. The absolute efficiency of the Ru­(bpy)3 2+/tri-n-propylamine (TPrA) ECL coreactant system taken as an example was found to be 10.0 ± 1.1% for the first time using 10 Hz potential stepping at a TPrA concentration of 10 mM, which quantifies a 3-fold enhancement in efficiency compared to that in the annihilation pathway. Our physical and analytical technique is anticipated to be an immediate and impactful methodology in the expanding field of ECL research.

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This study aimed to assess the feasibility of high hydrostatic pressure (HHP) treatment to obtain high quality juice, and prepared functional apple juice using fermentation technology. The physicochemical properties of HHP (10 min) pasteurized and pasteurized (85 °C, 15 min) apple juices were compared during fermentation. Moreover, the survival of Lactobacillus plantarum after fermentation under simulated gastrointestinal conditions was evaluated. Results showed that HHP-treated apple juice had better properties than that of pasteurized in terms of color difference, total phenol content, and antioxidant activity. After fermentation, about 2.00 log CFU/mL increase in viability of cells was observed and there was around 0.8 reduction in pH value, and the antioxidant capacities were also significantly improved. Additionally, the content of caffeic acid, ferulic acid, and chlorogenic acid significantly increased after 24 h of fermentation. The survival of Lactobacillus plantarum in simulated gastric fluid reached 97.37% after fermentation. Overall, HHP treatment is expected to be a substitute technology to pasteurization in order to obtain higher quality fermented fruit juice. This study could also be helpful for exploitation of fermented juice.