Formamidinium lead triiodide‐based perovskite solar cells have emerged as one of the most promising candidates that can be potentially used to develop photovoltaic technologies in the future. The commercial use of perovskite solar cell modules (PSCMs) is limited as it is challenging to fabricate high‐quality, efficient, and stable large‐area perovskite light‐absorbing films. Heptadecafluorooctanesulfonic acid tetraethylammonium salt (HFSTT), containing fluorinated long alkyl chains as hydrophobic tails and sulfonic acid groups (SO3−) as hydrophilic heads, which exhibit a great synergistic potential in large‐area film uniform fabrication, crystallization orientation modulation, defect passivation, and device operation stability enhancement, are introduced. The HFSTT‐modified films exhibit a prominent (100) orientation and lower trap‐state density as well as enhanced carrier mobilities and diffusion lengths, facilitating a champion unit device with an impressive power conversion efficiency (PCE) of 23.88% (0.14 cm2) and 22.52% (1 cm2) with a low voltage deficit around 0.341 V. The unencapsulated device retains ≈70% of its initial efficiency after 1000 h under heat damping test (60 °C and ≈60% RH). Moreover, the PSCMs exhibiting PCEs of 21.05% (with notable fill factor 0.79) and 18.27% are characterized by the active areas of 25.98 and 60.68 cm2, respectively.
Lipopolysaccharides (LPS), also commonly known as lipoglycans and endotoxins, can often accidentally contaminate recombinant protein therapeutics and bacteria-derived plasmid DNA vaccines. Since LPS can induce fever, hypotension, shock, and even death, their early and sensitive detection is necessary in relevant bioassays and for parenteral drug administration and/or biotherapeutics. In this study, an optical biosensor was developed using LPS-specific single-stranded DNA aptamers as LPS-selective probes. (3-Aminopropyl) triethoxysilane and glutaraldehyde were used as linkers to immobilize the LPS high-affinity aptamer on glass. Subsequently, each modification step was characterized by the optical responses obtained from liquid crystals using a polarized optical microscope. The sensor's ability to detect LPS was confirmed using a broad LPS detection range (5.5 pg/mL -100 ng/mL). Despite the presence of plasmid DNA, RNA, and bovine serum albumin, the aptamer sensor showed high selectivity for LPS and could be regenerated for reuse at a low pH, thus, providing a promising option for detecting LPS in complex, low pH environments.[a] Prof.
A liquid crystal (LC)-based pH sensor for real-time monitoring of variations in localized pH values near the LC droplets was developed, and its applicability for the detection of acidic gases was explored. It was found that 4-cyano-4′-pentylbiphenyl (5CB), when doped with hexanoic acid (HA), shows a bright-fan-shaped (planar orientation of LCs) to dark-cross (homeotropic orientation of LCs) optical response to a minimal change of the pH value (from 6.5 to 6.6). The fast and intensive pH-driven optical response can be explained mainly with the orientational transitions of 5CB, induced by the protonation and deprotonation of HA at the interface of aqueous/LC droplet. Because of its high pH sensitivity, the LC-based sensor was further exploited for monitoring the local pH changes, which were originated from concentration changes of acidic gases. The results suggested that at an industrial scale/production environment, the sensor shows excellent performance for long-term monitoring and sensing of acidic gases. This type of LC-based sensor may find to fulfill its applicability potential in the trace measurement of acidic gases.
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