ACS Central Science最新文献

To track changes in the colors of eucalyptus, this Ngugi researcher gathers knowledge in Aboriginal communities as well as in the lab.

As a vital process for solar fuel synthesis, water oxidation remains a challenging reaction to perform using durable and cost-effective systems. Despite decades of intense research, our understanding of the detailed processes involved is still limited, particularly under photochemical conditions. Recent research has shown that the overall kinetics of water oxidation by a molecular dyad depends on the coordination between photocharge generation and the subsequent chemical steps. This work explores similar effects of heterogeneous solar water oxidation systems. By varying a key variable, the reaction temperature, we discovered distinctly different behaviors on two model systems, TiO₂ and Fe₂O₃. TiO₂ exhibited a monotonically increasing water oxidation performance with rising temperature across the entire applied potential range, between 0.1 and 1.5 V vs the reversible hydrogen electrode (RHE). In contrast, Fe₂O₃ showed increased performance with increasing temperature at high applied potentials (>1.2 V vs RHE) but decreased performance at low applied potentials (<1.2 V vs RHE). This decrease in performance with temperature on Fe₂O₃ was attributed to an increased level of electron–hole recombination, as confirmed by intensity-modulated photocurrent spectroscopy (IMPS). The origin of the differing temperature dependences on TiO₂ and Fe₂O₃ was further ascribed to their different surface chemical kinetics. These results highlight the chemical nature of charge recombination in photoelectrochemical (PEC) systems, where surface electrons recombine with holes stored in surface chemical species. They also indicate that PEC kinetics are not constrained by a single rate-determining chemical step, highlighting the importance of an integrated approach to studying such systems. Moreover, the results suggest that for practical solar water splitting devices higher temperatures are not always beneficial for reaction rates, especially under low driving force conditions.

Varying temperature measurements reveal that the photophysical processes and the subsequent chemical steps exhibit mutual influence on each other in photoelectrochemical water oxidation reactions.

As a vital process for solar fuel synthesis, water oxidation remains a challenging reaction to perform using durable and cost-effective systems. Despite decades of intense research, our understanding of the detailed processes involved is still limited, particularly under photochemical conditions. Recent research has shown that the overall kinetics of water oxidation by a molecular dyad depends on the coordination between photocharge generation and the subsequent chemical steps. This work explores similar effects of heterogeneous solar water oxidation systems. By varying a key variable, the reaction temperature, we discovered distinctly different behaviors on two model systems, TiO₂ and Fe₂O₃. TiO₂ exhibited a monotonically increasing water oxidation performance with rising temperature across the entire applied potential range, between 0.1 and 1.5 V vs the reversible hydrogen electrode (RHE). In contrast, Fe₂O₃ showed increased performance with increasing temperature at high applied potentials (>1.2 V vs RHE) but decreased performance at low applied potentials (<1.2 V vs RHE). This decrease in performance with temperature on Fe₂O₃ was attributed to an increased level of electron-hole recombination, as confirmed by intensity-modulated photocurrent spectroscopy (IMPS). The origin of the differing temperature dependences on TiO₂ and Fe₂O₃ was further ascribed to their different surface chemical kinetics. These results highlight the chemical nature of charge recombination in photoelectrochemical (PEC) systems, where surface electrons recombine with holes stored in surface chemical species. They also indicate that PEC kinetics are not constrained by a single rate-determining chemical step, highlighting the importance of an integrated approach to studying such systems. Moreover, the results suggest that for practical solar water splitting devices higher temperatures are not always beneficial for reaction rates, especially under low driving force conditions.

Hepatocellular carcinoma (HCC) is by far the predominant malignant liver cancer, with both high morbidity and mortality. Early diagnosis and surgical resections are imperative for improving the survival of HCC patients. However, limited by clinical diagnosis methods, it is difficult to accurately distinguish tumor tissue and its boundaries in the early stages of cancer. Herein, we report two fluorescent probes, cLG and hLR, for the detection of cancer and healthy cells, respectively, enabling the precise diagnosis of liver cancer by providing complementary imaging. These two fluorescent probes could selectively stain the target cells in the liver tissue imaging, which is confirmed by H&E and antibody staining. Moreover, for the first time, the cancerous area and healthy area are clearly identified by the cocktail of these two probes, suggesting its potential to be used in fluorescence-guided surgery. Finally, we identify transporter SLC27A2 as the gating target of cLG through a systematic transporter screen using a CRISPR activation library. SMPD1 was identified as the target of hLR through a thermal proteome profiling. Therefore, the development of these two highly specific probes offers complementary imaging and provides a unique diagnostic tool for cancer disease, even for fluorescence-guided surgery.

Genetic encoding of noncanonical amino acids (ncAAs) with desired functionalities is an invaluable tool for the study of biological processes and the development of therapeutic drugs. However, existing ncAA incorporation strategies are rather time-consuming and have relatively low success rates. Here, we develop a virtual ncAA screener based on the analysis and modeling of the chemical properties of all reported ncAA substrates to virtually determine the recognition potential of candidate ncAAs. Using this virtual screener, we designed and incorporated several novel Lys and Phe derivatives into proteins for various downstream applications. Among them, the genetic encoding of an electron-rich Phe analog, 3-dimethylamino-phenylalanine, was successfully applied to enhance the cation-π interaction between histone methylation and its reader proteins. Thus, our virtual screener provides a fast and powerful strategy to efficiently incorporate ncAAs with diverse functionalities.

We have developed a virtual noncanonical amino acid (ncAA) screener that allows evaluation of the genetic encodability of designed ncAAs with desired functionalities prior to chemical synthesis.

Genetic encoding of noncanonical amino acids (ncAAs) with desired functionalities is an invaluable tool for the study of biological processes and the development of therapeutic drugs. However, existing ncAA incorporation strategies are rather time-consuming and have relatively low success rates. Here, we develop a virtual ncAA screener based on the analysis and modeling of the chemical properties of all reported ncAA substrates to virtually determine the recognition potential of candidate ncAAs. Using this virtual screener, we designed and incorporated several novel Lys and Phe derivatives into proteins for various downstream applications. Among them, the genetic encoding of an electron-rich Phe analog, 3-dimethylamino-phenylalanine, was successfully applied to enhance the cation-π interaction between histone methylation and its reader proteins. Thus, our virtual screener provides a fast and powerful strategy to efficiently incorporate ncAAs with diverse functionalities.

Hepatocellular carcinoma (HCC) is by far the predominant malignant liver cancer, with both high morbidity and mortality. Early diagnosis and surgical resections are imperative for improving the survival of HCC patients. However, limited by clinical diagnosis methods, it is difficult to accurately distinguish tumor tissue and its boundaries in the early stages of cancer. Herein, we report two fluorescent probes, cLG and hLR, for the detection of cancer and healthy cells, respectively, enabling the precise diagnosis of liver cancer by providing complementary imaging. These two fluorescent probes could selectively stain the target cells in the liver tissue imaging, which is confirmed by H&E and antibody staining. Moreover, for the first time, the cancerous area and healthy area are clearly identified by the cocktail of these two probes, suggesting its potential to be used in fluorescence-guided surgery. Finally, we identify transporter SLC27A2 as the gating target of cLG through a systematic transporter screen using a CRISPR activation library. SMPD1 was identified as the target of hLR through a thermal proteome profiling. Therefore, the development of these two highly specific probes offers complementary imaging and provides a unique diagnostic tool for cancer disease, even for fluorescence-guided surgery.

cLG and hLR are presented to detect cancerous and healthy cells, respectively. This pair of fluorescent probes can accurately imaging liver cancer by providing dual-color imaging.