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A polarity-sensitive probe was developed to simultaneously label lysosomes and endoplasmic reticulum (ER) via its dansylamide and rhodamine fluorescence, respectively, enabling ratiometric polarity detection and stable dual-labeling. The fragmented ER network and increased lysosomal polarity during ferroptosis were revealed, which facilitates the understanding of ferroptotic mechanisms.

Photouncaging delivers compounds with high spatial and temporal control to induce or inhibit biological processes but the released compounds may diffuse out. We here demonstrate that sulfonate anions can be photocaged so that a membrane impermeable compound can enter cells, be uncaged by photoirradiation and trapped within the cell.

Spherical assemblies named "reverse micellar vesicles" from self-assembling psuedopeptidic bottlebrush polymers are reported. These assemblies exhibited the combined features of both micelles and vesicles viz. molecular arrangement of classical micelles and dimensions similar to that of classical vesicles. Comprehensive ultramicroscopic and spectroscopic analyses were performed to delineate the hierarchical mechanism of their formation.

Herein, we introduce versatile molecular tools that enable specific delivery and visualization of photoswitchable lipids at cellular membranes, namely at the plasma membrane and internal membranes. These molecules were prepared by tethering ortho-nitrobenzyl-based fluorescent cages with a signaling lipid bearing an azobenzene photoswitch. They permit two sequential photocontrolled reactions, which are uncaging of a lipid analogue and then its repeated activation and deactivation. We used these molecules to activate GPR40 receptor transiently expressed in HeLa cells and demonstrated downstream modulation of intracellular Ca2+ levels.

In this work, we have developed a rhodamine dye based water-soluble, mitochondria-indicating photocage, which gets activated in the mitochondria producing a fluorescent signal and on-demand releases the caged anticancer drug, chlorambucil, in the cancer cells selectively upon irradiation of green light.

Nanoparticle-cell-nanoparticle communication by stigmergy was demonstrated using two capped nanodevices. The first community of nanoparticles (i.e.S(RA)IFN) is loaded with 9-cis-retinoic acid and capped with interferon-γ, whereas the second community of nanoparticles (i.e.S(sulf)PIC) is loaded with sulforhodamine B and capped with poly(I:C). The uptake of S(RA)IFN by SK-BR-3 breast cancer cells enhanced the expression of TLR3 receptor facilitating the subsequent uptake of S(sulf)PIC and cell killing.

The first NIR fluorescent mitochondria-targeting K+ sensor, denoted as TAC-Rh, was developed. The produced sensor consists of a rhodamine analog as the fluorophore and triazacryptand (TAC) as the K+ recognition unit. Compared to the K+ sensors reported previously, TAC-Rh exhibits two unique optical properties: the largest Stokes shifts (120 nm) and the longest emission peak wavelength (720 nm). With the assistance of this novel sensor, real-time changes of K+ concentrations in mitochondria during apoptosis were monitored for the first time. Moreover, it was also the first time that the relationship between mitochondrial K+ flux and apoptosis was investigated in real time using fluorescence imaging.

A photoactivatable fluorogenic tetrazine-rhodaphenothiazine probe was synthesized and studied in light-assisted, bioorthogonal labeling schemes. Experimental results revealed that the bioorthogonally conjugated probe efficiently sensitizes 1 O 2 generation upon illumination with green or orange light and undergoes self-oxidation leading to an intensely fluorescent sulfoxide product. An added value of the present probe is that it is also suitable for STED super-resolution microscopy using a 660 nm depletion laser.

Biotemplating makes it possible to prepare materials with complex structures by taking advantage of nature's ability to generate unique morphologies. In this work, we designed and produced a multi-scale porosity (MSP) scaffold starting from sea urchin spines by adding an additional nano-porosity to its native micro-porosity. The final replica shows porosity in both length scales and is an effective high-performing photocatalytic material.

A novel nanoarchitecture (MSN-Tb-UbR) was prepared by modifying rhodamine B-labelled Ubs (Ub-Rs) on the surface of mesoporous silica nanoparticles (MSNs) loaded with Tb 3+ -complexes. The MSN-Tb-UbR exhibits ratiometric sensing ability for DUB (UCH-L1) with good sensitivity and selectivity.

A group of asymmetric Si-rhodamine scaffolds was designed for protease-activated NIR probes. Dual pH-inertia for both spirocyclized fluorescent probes and fluorescent products of zwitterions form over a wide range of pH (4.0-11.0). Leucine aminopeptidase (LAP) and γ-glutamyl transpeptidase (GGT) were monitored by fluorescent imaging in vivo.

Abnormal vitamin B6 status, marked by deficient intracellular concentrations of pyridoxal phosphate (PLP), is classified as a direct biomarker based on its biomedical significance. However, there exist no direct methods for measuring vitamin B6 status in intact cells. Here we describe the development of a fluorogenic probe, RAB6, which shows remarkable selectivity for PLP among the B6 vitamers and other cellular aldehydes.

The selective measurement of cellular pH at specific regions is significant for the in-depth study of cell functions and pathological processes. Herein, we combined our previously developed rhodamine B-labeled cell-penetrating peptide spirolactam derivative with quantum dots to create a ratiometric nanobiosensor for the simultaneous sensing and imaging of lysosomes and extracellular pH.

A highly selective lysosome-targeting NIR fluorescent probe (Lyso-SiR-2S) for HOCl was constructed based on Si-rhodamine B spirodithiolactone. This probe was very effectively employed to sense HOCl produced in various living cells and to visualize fluctuations of endogenous HOCl resulting from GEN-induced acute kidney injury in vivo for the first time.

We reported two simple rhodamine-based colourimetric sensors for the first time which can selectively and sensitively detect salicylic acid (SA) under naked-eye detection. We proposed two distinctly different modes to elucidate the possible mechanism for monitoring SA. The rationally designed probes can be well exploited in signalling SA in living cell lines.

A multifunctional G-PyB/KCl hydrogel showed outstanding self-healability, high conductivity, and rapid room-temperature phase-selective gelation capacity, and was developed as an electrochemical aptamer sensing platform for the ultrasensitive detection of alpha-fetoprotein.

A π-extended red absorbing Se-rhodamine (Se-NR) was synthesised and characterized. By masking the amine of Se-NR as an azide, we successfully constructed a bio-orthogonally activatable photosensitizer (Se-NR-Az). Se-NR-Az was not photocytotoxic, but when activated by the Staudinger reaction, photocytotoxicity was restored.

We present the first Golgi-targeted small-molecular pH-sensitive fluorescent probe RSG, which allows an off-on fluorescence response to Golgi acidification with high sensitivity and specificity. RSG has been successfully used for real-time monitoring of Golgi pH changes induced by drug treatment at the cellular level, as well as by the LPS-mediated inflammation in vivo.

We developed a fluorescent pH probe (1) capable of two-photon excitation and far-visible-emission based on FRET, composed of naphthalimide-piperazine-rhodamine. It exhibited a pH-dependent reversible and fast ratiometric fluorescence change in the rhodamine emission. Probe 1 was applied to image the pH perturbations of mitochondria in living cells and tissues.

We designed an enzyme-activatable probe for real time in situ tracking of MT1-MMP activity. The MT1-MMP responses of endothelial cells were investigated under the regulation of shear stress and biochemical factor on a microfluidic chip. This strategy can be beneficial to evaluate membrane protein responses to external stimuli and to engineer cells for basic and clinical research.

Proximity binding-induced DNA assemblies possessing outstanding flexibility and diversity can provide great accessibility for output translation of amplifiable DNA probes or directly detectable signals. Based on a novel protein-responsive DNA assembly constructed via proximity binding-initiated rolling circle amplification (RCA), we present a sensitive and specific fluorescence resonance energy transfer (FRET) strategy for the immunoassay of mucin 1 (MUC1). The resultant RCA product containing numerous and continuous repeats as the tandem template accelerates the transduction of signal probes through the disassembly of triple-helix stem structure (THSS), achieving a significantly amplified FRET signal readout.

A novel tumor-selective catalytic nanosystem that enables efficient chemodynamic therapy (CDT) and activatable fluorescence imaging in H2O2-rich tumor microenvironments has been developed.

A synthetic three-fluorophore system with two enzymatically cleavable linkers has been developed for the simultaneous detection of two proteases in a mixture. The probe was designed to afford single excitation/triple emission ratiometric detection through a fluorescence change during the cleavage of a peptide linker. The developed assays were verified for trypsin and chymotrypsin as the model enzymes.

Even for short peptides that are enriched in basic amino acids, the large chemical space that can be spanned by combinations of natural amino acids hinders the rational design of cell penetrating peptides. We here report on short oligoalanine scaffolds for the fine-tuning of peptide helicity in different media and the study of cell penetrating properties. This strategy allowed the extraction of the structure/activity features required for maximal membrane interaction and cellular penetration at minimal toxicity. These results confirmed oligoalanine helical callipers as optimal scaffolds for the rational design and the identification of cell penetrating peptides.

Fluorescent unimolecular micelles (FUMs) with multicolor emission acting as fluorescent nanoagents for optical fluorescence imaging have, for the first time, been reported. The FUMs show good water-solubility, ultra-small size, and enhanced biocompatibility, which endow the FUMs with versatile applications including organelle labeling, multicolor markers and high tumor accumulation, revealing that our design can serve as a rational strategy for the development of UM-based fluorescent nanoagents for bioprocess monitoring.

Boronic acid liposomes enable triggered content release and cell delivery driven by carbohydrate binding. Dye release assays using hydrophilic and hydrophobic fluorophores validate dose-dependent release upon carbohydrate treatment. Microscopy results indicate dramatic enhancements in cell delivery, showcasing the prospects of boronic acid lipids for drug delivery.

We report the discovery of ebselen-based dual covalent inhibitors of metallo-β-lactamases. Fluorescence and MALDI-TOF analysis suggested that the scaffold could bind to NDM-1 by forming a S-Se bond with Cys221 and an amide bond with Lys224 of NDM-1, thereby exhibiting selective inhibition and labeling against B1 and B2 subclass enzymes in vitro and in vivo.

A fluorescent probe that enables ratiometric imaging of endogenous hypochlorous acid (HOCl) in cells and tissues by two-photon microscopy is developed based on a red-emitting acetyl-benzocoumarin (AcBC) dye. An oxathiolane group in the probe reacts with HOCl to generate the AcBC dye, which involves a ratiometric fluorescence change only toward HOCl along with high sensitivity.

The synthesis of a novel rectilinearly π-extended rhodamine dye (TJ730) has been described. It exhibits NIR fluorescence emission with a Stokes shift of >110 nm. TJ730 and its ester derivative are cell permeable, have low cytotoxicity, are biocompatible, and can be directly used as NIR tracers for lysosome staining. Using TJ730 as a precursor, two probes have been prepared for Cu 2+ .

A new naphthol-based rhodamine derivative (NpRD) has been developed for the selective and differential detection of adenosine 3',5'-cyclic monophosphate (cAMP) and adenosine phosphates (APs) (ATP, ADP, and AMP) from other nucleotides. The simple detection and quantification of cAMP in human blood cells and in other samples based on the 'turn on' fluorescence properties of this chemosensor through colorimetry or fluorometry makes it unique for probable application in high throughput screening.

A biotin-rhodamine-TPP conjugate (BiTClO) was reported as a real-time (within 10 s) fluorescent probe for the sensing of mitochondrial hypochlorite with excellent selectivity and high sensitivity (0.21 μM). Moreover, it is the first tumor-specific and mitochondria-targeted fluorescent probe applied in cell imaging.

Here we report the conception, synthesis and evaluation of new hydrophilic rhodamine-based enzymatic substrates for detection of peptidase activity compatible with high-throughput screening using droplet-based microfluidics.

Here we show that graphene oxide greatly enhances the imaging ability of a peptide probe that selectively targets microtubules of the cytoskeleton, thus enabling the dynamic tracking of mitosis in live cells.

Cargo delivery from mesoporous silica nanoparticles loaded with sulforhodamine B and capped with a difluoroboron-dipyrromethene (BODIPY) derivative was triggered by a NO 2 -induced oxidative process.

The full capabilities of membrane proteins in bionanotechnology can only be realised through improvements in their reconstitution environments that combine biocompatibility to support function and durability for long term stability. We demonstrate that hybrid vesicles composed of natural phospholipids and synthetic diblock copolymers have the potential to achieve these criteria.

Due to the effective properties of the FRET signal and K + -sensitive recognition of G-quadruplex, aptamer-based FRET nanoflares were developed to sense intracellular potassium ions.

This work proposes a gold nanoparticle (AuNP) based probe to study the single-nanoparticle translocation behavior through a silicon nitride (SiNx) solid-state nanopore. The AuNP probe is functionalized with a rhodamine derivative molecule, termed Rhod-DPA, whose fluorescence can be activated in the presence of Cu(2+) due to the binding between Rhod-DPA and Cu(2+). The Cu(2+) triggered configuration change of Rhod-DPA on the probe surface can induce the plasmon resonance energy transfer (PRET) from single AuNPs to the transformed fluorescent molecules, which can be detected by the color change of AuNP probes under dark-field microscopy (DFM) and their scattering spectra recorded on a spectrometer. By analyzing the peak shifts before and after the addition of Cu(2+), evidence of single nanoparticle translocation through the nanopore has been obtained, proving the successful establishment of the tracking strategy.

The first fully conjugated bis-cyclopropenone (photo-DIBOD), a derivative of dibenzo[a,e][8]annulene, has been synthesized. 350-420 nm irradiation of this robust compound results in the efficient formation of dibenzo [a,e] cyclooctadiyne, an unstable, but useful SPAAC cross-linking reagent. Since photo-DIBO doesn't react with organic azides, this method allows for the spatiotemporal control of the ligation of two azide-tagged substrates.

A supramolecular gel formed by coordination of Zn(2+) with adenosine monophosphate (AMP) is reported. The adenine base, the monophosphate, and Zn(2+) are all important for gel formation. Mechanically disrupted gels can re-form upon centrifugation; applications of this gel for guest-molecule entrapment are explored.

We report a substitution of 9-phenylanthracenyl group into rhodamine derivatives that can induce the J-aggregate formation of rhodamine moieties in the aqueous solution upon the addition of a halide ion. From X-ray crystallographic analysis, the dramatic red-shift in the absorption band (i.e. app. 100 nm) originates from the cooperative slipped-stacking of rhodamine and anthracene molecules.

We have experimentally shown significant suppression of metal-induced fluorescence (FL) quenching on plasmo-photonic metasurfaces by incorporating a self-assembled monolayer (SAM) of sub-nm thickness. The FL signals of rhodamine dye molecules have been several-ten-fold enhanced by introducing the SAM, in comparison with the previous configuration contacting molecules and metal surfaces.

An o-fluorinated-azido-capped rhodamine probe can react with H2S efficiently and selectively to give large off-on fluorescence enhancement. The probe was used to develop an assay for cystathionine β-synthase acitivity and for in situ visualization of endogenously produced H2S in living cells.

Using total internal fluorescence microscopy, highly parallel measurements of single lipid vesicles unexpectedly reveal that a small fraction of vesicles rupture in multiple discrete steps when destabilized by a membrane-active peptide which is in contrast to classical solubilization models. To account for this surprizing kinetic behaviour, we identified that this vesicle subpopulation consists of multilamellar vesicles, and that the outermost lamella is more susceptible to rupture than unilamellar vesicles of even smaller size. This finding sheds light on the multiple ways in which membrane configuration can influence strain in the bilayer leaflet and contribute to nm-scale membrane curvature sensing.

We developed a new self-signaling sensory system built on phospholipid liposomes having H-aggregated R6G dyes on their surface. Selective molecular recognition of a target by the phospholipid displaces R6G from the liposome surface to turn on fluorescence signal. Selective and sensitive detection of neomycin down to 2.3 nM is demonstrated.

A cyclic boronate structure was incorporated into Si-rhodamine to design a pH-activatable near-infrared (NIR) probe based on the reversible ring-opening process triggered by H(+). The probe showed general suitability of specific labelling of acidic lysosomes and tracking their pH changes in living cells.

The first ratiometric fluorescent probe for the detection of a nerve agent simulant was developed based on tandem phosphorylation and intramolecular cyclization, by which high sensitivity as well as large emission shift could be achieved.

We develop a triple-color fluorescent probe which may function as a lab-on-a-DNA-molecule for simultaneous detection of multiple exonucleases/restriction endonucleases. This triple-color fluorescent probe can be further applied for the discrimination of seven exonucleases and four cell lines as well as the screening of various nuclease inhibitors.

A ratiometric fluorescent probe () for ClO(-) based on the conjugate of coumarin-rhodamine was presented, which could sense ClO(-) with fast response (within 5 s), high sensitivity and excellent selectivity. More importantly, is the first mitochondria-targeted ratiometric fluorescent probe to image exogenous and endogenous ClO(-).

A fluorescent logic gate probe has been constructed for sensing two biologically interactive signaling molecules, H2S and NO. This probe showed distinct fluorescence signals towards H2S and NO in aqueous media and in live cells. The strategy may provide new evidence that the logic gate can serve as an ideal approach for sensing multiple targets.

The BSA-Cu3(PO4)2·3H2O hybrid nanoflower was used as a biomimetic catalyst with excellent catalytic activity, durability and stability. When GOx was used as the protein component, this composite could realize self-activated cascade catalysis. Our nanoflower system could also be used to decompose organic pollutants with high efficiency.