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Later flow immunochromatographic assay has been widely used in clinical, environmental, and other diagnostic applications owing to its high sensitivity and throughput. However, most immunoassays operate in the "turn-off" mode for detecting targets of low molecular weight. The signal intensity decreases as the analyte concentration increases, which poses a challenge for achieving ultrasensitive detection at low concentrations and is counterintuitive to new users. In this work, a fluorometric immunochromatographic assay (FICA) is developed to simultaneously read "turn-on" fluorescent and "turn-off" colorimetric signals, where ZnCdSe/ZnS quantum dots act as fluorescence donors and gold nanoparticles (AuNPs) act as quenchers. The fluorescent signal (excitation/emission wavelengths of 365/525 nm) is positively correlated with analytes' concentration. Taking sibutramine (SBT) as the analysis target, the visual limit of detection for SBT reached 3.9 ng/mL, and the limit of Quantitation was 5.0 ng/mg in spiked samples. The developed FICA achieves a high sensitivity in SBT detection, which is much lower than that of the colloidal gold-based immunochromatographic assay. This dual-function detection mode has great potential to be used as a rapid on-site semiquantitative method, providing an alternative mode for the determination of low levels of target analytes., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Pyrogenic carbon and magnetite (Fe 3 O 4 ) were mixed together for the activation of hydrogen peroxide (H 2 O 2 ), aiming to enhance the oxidation of refractory pollutants in a sustainable way. The experimental results indicated that the straw-derived carbon obtained by pyrolysis at 500-800 °C was efficient on coactivation of H 2 O 2 , and the most efficient one was that prepared at 700 °C (C700) featured with abundant defects. Specifically, the reaction rate constant ( k obs ) for removal of an antibiotic ciprofloxacin in the coactivation system (C700/Fe 3 O 4 /H 2 O 2 ) is 12.5 times that in the magnetite-catalyzed system (Fe 3 O 4 /H 2 O 2 ). The faster pollutant oxidation is attributed to the sustainable production of • OH in the coactivation process, in which the carbon facilitated decomposition of H 2 O 2 and regeneration of Fe(II). Besides the enhanced H 2 O 2 utilization in the coactivation process, the leaching of iron was controlled within the concentration limit in drinking water (0.3 mg·L -1 ) set by the World Health Organization., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

A colorimetric sensor detects an analyte by utilizing the optical properties of the sensor unit, such as absorption or reflection, to generate a structural color that serves as the output signal to detect an analyte. Detecting the refractive index of an analyte by recording the color change of the sensor structure on its surface has several advantages, including simple operation, low cost, suitability for onsite analysis, and real-time detection. Colorimetric sensors have drawn much attention owing to their rapidity, simplicity, high sensitivity and selectivity. This Review discusses the use of colorimetric sensors in the food industry, including their applications for detecting food contaminants. The Review also provides insight into the scope of future research in this area., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

In this study, the adsorption capability and gas-sensing performance of Cu 2 O-graphene on SF 6 -featured decomposers (H 2 S and SO 2 ) were evaluated based on first-principles calculations. The most stable structure, adsorption energy, band structure, and DOS and PDOS were used to investigate the adsorption mechanism. The findings suggest that all adsorption systems are exothermic and spontaneous. The density of states analysis suggests that the adsorption of H 2 S and SO 2 is chemisorbed. The recovery time shows that the desorption time after H 2 S adsorption is shorter at a suitable temperature. In contrast, the desorption time of SO 2 was quite long in some systems, which reduced the detection efficiency. In summary, Cu 2 O-graphene could be a promising gas-sensing material for the detection of two-characteristic SF 6 -decomposition products., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

DNA-encoded library (DEL) is a powerful ligand discovery technology that has been widely adopted in the pharmaceutical industry. DEL selections are typically performed with a purified protein target immobilized on a matrix or in solution phase. Recently, DELs have also been used to interrogate the targets in the complex biological environment, such as membrane proteins on live cells. However, due to the complex landscape of the cell surface, the selection inevitably involves significant nonspecific interactions, and the selection data are much noisier than the ones with purified proteins, making reliable hit identification highly challenging. Researchers have developed several approaches to denoise DEL datasets, but it remains unclear whether they are suitable for cell-based DEL selections. Here, we report the proof-of-principle of a new machine-learning (ML)-based approach to process cell-based DEL selection datasets by using a Maximum A Posteriori (MAP) estimation loss function, a probabilistic framework that can account for and quantify uncertainties of noisy data. We applied the approach to a DEL selection dataset, where a library of 7,721,415 compounds was selected against a purified carbonic anhydrase 2 (CA-2) and a cell line expressing the membrane protein carbonic anhydrase 12 (CA-12). The extended-connectivity fingerprint (ECFP)-based regression model using the MAP loss function was able to identify true binders and also reliable structure-activity relationship (SAR) from the noisy cell-based selection datasets. In addition, the regularized enrichment metric (known as MAP enrichment) could also be calculated directly without involving the specific machine-learning model, effectively suppressing low-confidence outliers and enhancing the signal-to-noise ratio. Future applications of this method will focus on de novo ligand discovery from cell-based DEL selections., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

In this paper, based on density functional theory, the adsorption mechanism and gas sensitivity of Ag 2 O/CuO-modified SnS 2 were analyzed. The results were analyzed according to the adsorption energy, total density of states, partial density of states, and frontier molecular orbital theory. The results show that the adsorption of all gas molecules is exothermic. NH 3 , Cl 2 , and C 2 H 2 gases are chemisorbed on the modified SnS 2 surfaces. After gas adsorption, the energy gap of the base changes by more than 10%, which fully shows that the conductivity changes greatly after gas adsorption, which can be reflected in the macroscopic resistance change. Ag 2 O-SnS 2 is suitable as a gas sensor for NH 3 gas sensors in terms of moderate adsorption distance, large adsorption energy, charge transfer, and frontier molecular orbital theory, while CuO-SnS 2 is more suitable as a C 2 H 2 gas sensor., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

DNA-encoded library (DEL) is an efficient high-throughput screening technology platform in drug discovery and is also gaining momentum in academic research. Today, the majority of DELs are assembled and encoded with double-stranded DNA tags (dsDELs) and has been selected against numerous biological targets; however, dsDELs are not amendable to some of the recently developed selection methods, such as the cross-linking-based selection against immobilized targets and live-cell-based selections, which require DELs encoded with single-stranded DNAs (ssDELs). Herein, we present a simple method to convert dsDELs to ssDELs using exonuclease digestion without library redesign and resynthesis. We show that dsDELs could be efficiently converted to ssDELs and used for affinity-based selections either with purified proteins or on live cells., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Cu 2 S-MoSe 2 was selected as a gas-sensing material to detect NO 2 and NH 3 . Based on density functional theory calculations, the adsorption structures, density of states, molecular orbit, and recovery time were studied to analyze the gas-sensing mechanism of Cu 2 S-MoSe 2 to gases. Calculation results show that Cu 2 S clusters receive a stable doping structure on the MoSe 2 surface. Compared with intrinsic MoSe 2 , Cu 2 S-MoSe 2 shows more excellent adsorption performance to NO 2 and NH 3 due to the active feature of the Cu 2 S dopant. After NO 2 and NH 3 adsorption, the energy gap decreases, indicating an improvement of the conductivity, which is greatly significant for gas sensing. For double NH 3 adsorption, the conductivity of the entire system increases more than that of a double NO 2 adsorption system, signifying the sensitivity of Cu 2 S-MoSe 2 is greater for NH 3 than NO 2 . The results of theoretical recovery time show that Cu 2 S-MoSe 2 is sensitive for NH 3 detection at room temperature (298 K) and NO 2 detection at high temperature (400 K)., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Highly enantioselective Friedel-Crafts alkylation of pyrroles with 2-enoyl-pyridine N -oxides in water/chloroform (10:1) was developed under catalysis of Lewis acid. The Friedel-Crafts alkylation products can be obtained in high yields and excellent enantioselectivities. Moreover, several control experiments were carried out to study the reaction mechanism., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

Realizing the diagnosis of lung cancer at an inchoate stage is significant to get valuable time to conduct curative surgery. In this work, we relied on a density functional theory (DFT)-proposed Ru-SnS 2 monolayer as a novel, promising biosensor for lung cancer diagnosis through exhaled gas analysis. The results indicated that the Ru-SnS 2 monolayer has admirable adsorption performance for three typical volatile organic compounds (VOCs) of lung cancer patients, which therefore results in a remarkable change in the electronic behavior of the Ru-doped surface. As a consequence, the conductivity of the Ru-SnS 2 monolayer increases after gas adsorption based on frontier molecular orbital theory. This provides the possibility to explore the Ru-SnS 2 monolayer as a biosensor for lung cancer diagnosis at an early stage. In addition, the desorption behavior of three VOCs from the Ru-SnS 2 surface is studied as well. Our calculations aim at proposing novel sensing nanomaterials for experimentalists to facilitate the progress in lung cancer prognosis., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

To ensure the stable operation of gas-insulated equipment, removal of SF 6 decomposition products of sulfur hexafluoride (SF 6 ) is one of the best methods. SO 2 F 2 is one of the typical decomposition products of SF 6 , while the Au-modified MoS 2 (Au-MoS 2 ) monolayer is a novel gas adsorbent. Therefore, based on the first-principles calculation, the adsorption properties of the SO 2 F 2 molecule on the Au-MoS 2 monolayer are calculated. Furthermore, the adsorption energy, charge transfer, and structure parameters were analyzed to obtain the most stable adsorption structure. These results indicate that all of the adsorption processes are exothermic. To better study the adsorption mechanism between the SO 2 F 2 molecule and the Au-MoS 2 monolayer, the density of states, the highest occupied molecular orbital, the lowest unoccupied molecular orbital, and electron density difference were obtained. At last, we conclude that the interaction between the SO 2 F 2 molecule and the Au-MoS 2 monolayer was chemisorption. This study provides a theoretical basis to prepare the Au-MoS 2 monolayer for the removal of SF 6 decomposition products., Competing Interests: The authors declare no competing financial interest.

The detection of partial discharge by analyzing the decomposition components of SF 6 gas in gas-insulated switchgears plays an important role in the diagnosis and assessment of the operational state of power equipment. Recently, the application of transition metal-modified MoS 2 monolayer dioxide in gas detection has received wide attention. In this paper, first-principle density functional theory calculations were adopted to study the gas-sensitive response of Co-MoS 2 monolayer to SOF 2 and SO 2 F 2 . It is found that the conductivity of the Co-MoS 2 monolayer has been effectively enhanced after Co atom doping on the MoS 2 monolayer. After gas adsorption, electrons transfer from the Co-MoS 2 monolayer to the gas molecules, resulting in significant reduction of conductivity of the adsorption system. The calculation results reveal that the Co-MoS 2 monolayer is sensitive and selective to SOF 2 and SO 2 F 2 gases. This study provides the theoretical possibility of using Co-MoS 2 as a gas sensor for SOF 2 and SO 2 F 2 gas detection., Competing Interests: The authors declare no competing financial interest.