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Fluorophores and fluorophores‐based probes or labels can visualize the structures and content fluctuations of biomolecules, and have made great progress in the broad range of biomedicine fields. However, many commercially available fluorophores suffer from small Stokes shift, which results in insufficient signal‐to‐noise ratio and self‐quenching in advanced imaging techniques. Moreover, the small Stokes shift also hinders the application of fluorophores in some complex imaging, such as single‐excitation multicolor imaging. In the past two decades, many effects have been made to enlarge Stokes shift of fluorophores. In this review, we clarified the reasons for the small Stokes shift building on the structural analysis of fluorophores, systematically summarize the methods of structural modification to increase Stokes shift, and present some representative applications of fluorophores with large Stokes shift in imaging and sensing. [ABSTRACT FROM AUTHOR]

Organic fluorophores are indispensable tools in cells, tissue and in vivo imaging, and have enabled much progress in the wide range of biological and biomedical fields. However, many available dyes suffer from insufficient performances, such as short absorption and emission wavelength, low brightness, poor stability, small Stokes shift, and unsuitable permeability, restricting their application in advanced imaging technology and complex imaging. Over the past two decades, many efforts have been made to improve these performances of fluorophores. Starting with the luminescence principle of fluorophores, this review clarifies the mechanisms of the insufficient performance for traditional fluorophores to a certain extent, systematically summarizes the modified approaches of optimizing properties, highlights the typical applications of the improved fluorophores in imaging and sensing, and indicates existing problems and challenges in this area. This progress not only proves the significance of improving fluorophores properties, but also provide a theoretical guidance for the development of high‐performance fluorophores. [ABSTRACT FROM AUTHOR]

The accurate, rapid, and sensitive identification of cancer cells in complex physiological environments is significant in biological studies, personalized medicine, and biomedical engineering. Inspired by the naturally confined enzymes on fluid cell membranes, a fluidly confined CRISPR‐based DNA reporter (FINDER) was developed on living cell membranes, which was successfully applied for rapid and sensitive cancer cell identification in clinical blood samples. Benefiting from the spatial confinement effect for improved local concentration, and membrane fluidity for higher collision efficiency, the activity of CRISPR‐Cas12a was, for the first time, found to be significantly enhanced on living cell membranes. This new phenomenon was then combined with multiple aptamer‐based DNA logic gate for cell recognition, thus a FINDER system capable of accurate, rapid and sensitive cancer cell identification was constructed. The FINDER rapidly identified target cells in only 20 min, and achieved over 80 % recognition efficiency with only 0.1 % of target cells presented in clinical blood samples, indicating its potential application in biological studies, personalized medicine, and biomedical engineering. [ABSTRACT FROM AUTHOR]

Mature microRNAs (miRNAs) in extracellular vesicles (EVs) are involved in different stages of cancer progression, yet it remains challenging to precisely detect mature miRNAs in EVs due to the presence of interfering RNAs (such as longer precursor miRNAs, pre‐miRNAs) and the low abundance of tumor‐associated miRNAs. By leveraging the size‐selective ability of DNA cages and polyethylene glycol (PEG)‐enhanced thermophoretic accumulation of EVs, we devised a DNA cage‐based thermophoretic assay for highly sensitive, selective, and in situ detection of mature miRNAs in EVs with a low limit of detection (LoD) of 2.05 fM. Our assay can profile EV mature miRNAs directly in serum samples without the interference of pre‐miRNAs and the need for ultracentrifugation. A clinical study showed that EV miR‐21 or miR‐155 had an overall accuracy of 90 % for discrimination between breast cancer patients and healthy donors, which outperformed conventional molecular probes detecting both mature miRNAs and pre‐miRNAs. We envision that our assay can advance EV miRNA‐based diagnosis of cancer. [ABSTRACT FROM AUTHOR]

The development of photothermal agents (PTAs) with robust photostability and high photothermal conversion efficiency is of great importance for cancer photothermal therapy. Herein, a novel PTA was created using two‐dimensional intermetallic PtSnBi nanoplates (NPs), which demonstrated excellent photostability and biocompatibility with a high photothermal conversion efficiency of ∼61 % after PEGylation. More importantly, PtSnBi NPs could be employed as photoacoustic imaging contrast agents for tumor visualization due to their strong absorbance in the NIR range. In addition, both in vitro and in vivo experiments confirmed that PtSnBi NPs had a good photothermal efficacy under NIR laser irradiation. Therefore, the remarkable therapeutic characteristics of PtSnBi NPs make them a most promising candidate for cancer theranostics. [ABSTRACT FROM AUTHOR]

Clustered regularly interspaced short palindromic repeats (CRISPR) is a promising technology in the biological world. As one of the CRISPR‐associated (Cas) proteins, Cas12a is an RNA‐guided nuclease in the type V CRISPR‐Cas system, which has been a robust tool for gene editing. In addition, due to the discovery of target‐binding‐induced indiscriminate single‐stranded DNase activity of Cas12a, CRISPR‐Cas12a also exhibits great promise in biosensing. This minireview not only gives a brief introduction to the mechanism of CRISPR‐Cas12a but also highlights the recent developments and applications in biosensing and gene regulation. Finally, future prospects of the CRISPR‐Cas12a system are also discussed. We expect this minireview will inspire innovative work on the CRISPR‐Cas12a system by making full use of its features and advantages. [ABSTRACT FROM AUTHOR]

Artificial multi-enzyme systems with precise and dynamic control over the enzyme pathway activity are of great significance in bionanotechnology and synthetic biology. Herein, we exploit a spatially addressable DNA nanoplatform for the directional regulation of two enzyme pathways (G6pDH-MDH and G6pDH-LDH) through the control of NAD+ substrate channeling by specifically shifting NAD+ between the two enzyme pairs. We believe that this concept will be useful for the design of regulatory biological circuits for synthetic biology and biomedicine. [ABSTRACT FROM AUTHOR]

Recently, the binding ability of DNA on GO and resulting nuclease resistance have attracted increasing attention, leading to new applications both in vivo and in vitro. In vivo, nucleic acids absorbed on GO can be effectively protected from enzymatic degradation and biological interference in complicated samples, making it useful for targeted delivery, gene regulation, intracellular detection and imaging with high uptake efficiencies, high intracellular stability, and very low toxicity. In vitro, the adsorption of ssDNA on GO surface and desorption of dsDNA or well-folded ssDNA from GO surface result in the protection and deprotection of DNA from nucleic digestion, respectively, which has led to target-triggered cyclic enzymatic amplification methods (CEAM) for amplified detection of analytes with sensitivity 2-3 orders of magnitude higher than that of 1:1 binding strategies. This Concept article explores some of the latest developments in this field. [ABSTRACT FROM AUTHOR]