Besides genome editing, CRISPR-Cas12a has recently been used for DNA detection applications with attomolar sensitivity but, to our knowledge, it has not been used for the detection of small molecules. Bacterial allosteric transcription factors (aTFs) have evolved to sense and respond sensitively to a variety of small molecules to benefit bacterial survival. By combining the single-stranded DNA cleavage ability of CRISPR-Cas12a and the competitive binding activities of aTFs for small molecules and double-stranded DNA, here we develop a simple, supersensitive, fast and high-throughput platform for the detection of small molecules, designated CaT-SMelor ( C RISPR-Cas12a- and aT F-mediated s mall m ol e cu l e detect or ). CaT-SMelor is successfully evaluated by detecting nanomolar levels of various small molecules, including uric acid and p -hydroxybenzoic acid among their structurally similar analogues. We also demonstrate that our CaT-SMelor directly measured the uric acid concentration in clinical human blood samples, indicating a great potential of CaT-SMelor in the detection of small molecules.

Polymer electrolytes with high ionic conductivity, good interfacial stability and safety are in urgent demand for practical rechargeable lithium metal batteries (LMBs). Herein we propose a novel flame-retardant polymerized 1,...

Figure 3. a) N 1s and b) F 1s XPS spectra of SEI formed on the PDDA-TFSI@Cu, poly(EVIm-TFSI)@Cu, PDMA-TFSI@Cu, and bare Cu electrodes. c) Nucleation overpotentials of Li deposition on bare Cu electrode and the PIL-coated electrodes. d) Coulombic efficiency of Li/Cu half-cells using the bare Cu electrode and the PIL-coated electrodes at 0.5 mA cm −2 with a plating capacity of 1 mAh cm −2. e,f) Potential profiles of various electrodes at the 50th (e) and 100th (f) cycles.

Microorganisms such as bacteria and fungi produce a variety of specialized metabolites that are invaluable for agriculture, biological research, and drug discovery. However, the screening of microbial metabolic output is usually a time intensive task. Here we utilize a liquid micro-junction surface sampling probe for electrospray ionization mass spectrometry to extract and ionize metabolite mixtures directly from living microbial colonies grown on soft nutrient agar in Petri-dishes without any sample pre-treatment. To demonstrate the method is robust, this technique was applied to observe the metabolic output of more than 30 microorganisms, including yeast, filamentous fungi, pathogens, and marine-derived bacteria, that were collected worldwide. Diverse natural products produced from different microbes, including Streptomyces coelicolor, Bacillus subtilis, and Pseudomonas aeruginosa are further characterized.