Dual-response Probe Research Articles

Revealing the protective role of mitophagy for liver injury via a promising dual-channel activated fluorescent probe

As a highly active organelle in the regulation of hepatic cellular redox, the dysfunction of mitochondrial is tightly associated with both acute and chronic liver diseases. Mitophagy, the major pathway to maintenance of mitochondrial quality plays a vital role in the regulation of liver homeostasis by emerging evidence. Real time monitoring two or more mitochondrial microenvironment parameters alterations during mitophagy is more favorable for better elucidating the mitophagy process and its mechanism of action for liver disease. Here, we proposed a dual responsive probe named SP-DCN through effective crosslinking the fragments of spiropyrane and dicyanoisophorone for simultaneously monitoring of pH and viscosity. The mitophagy induced by different external stimulations all lead to the same changing trends of intracellular fluorescence signals in the two imaging channels. The enhancement of fluorescence ratio value in two channels were obtained in the tumor site and liver site of tumor bearing and liver injury mice, respectively. It was noted that the fluorescence ratio value could be served as a characteristic parameter to evaluate the intracellular mitophagy level. More importantly, the proposed dual-channel activated imaging method was successfully applied to confirm the protective effect of mitophagy against drug induced liver injury. This approach holds promise for further analysis the regulatory mechanisms of mitophagy in liver, and contributes to identify promising targets for the future treatment of liver diseases.

Dual-Responsive and Aggregation-Induced-Emission Probe for Selective Imaging of Infectious Urolithiasis.

Identifying infected stones is crucial due to their rapid growth and high recurrence rate. Here, the calcium-magnesium dual-responsive aggregation-induced emission (AIE)-active probe TCM-5COOH (Tricyano-methlene-pyridine-5COOH), distinctively engineered to distinguish high-threat infection calculi from metabolic stones, is presented. Upon incorporation of flexible alkyl carboxyl group, TCM-5COOH featuring five carboxyl moieties demonstrates excellent water solubility and enhanced penetration into porous infectious stones. The robust chelation of TCM-5COOH with stone surface-abundant Ca2+ and Mg2+ inhibits vibrational relaxation, thus triggering intense AIE signals. Remarkably, the resulting complex exhibits high insolubility, effectively anchoring within the porous structure of the infection calculi and offering prolonged illumination. Jobs' plot method reveals similar response characteristics for Ca2+ and Mg2+, with a 1:2 coordination number for both ions. Isothermal titration calorimetry (ITC) results demonstrate higher enthalpy change (ΔH) and lower entropy change (ΔS) for the reaction, indicating enhanced selectivity compared to TCM-4COOH lacking the alkyl carboxyl group. Synchrotron X-ray absorption fine spectroscopy (XAFS) validates TCM-5COOH's interaction with Ca2+ and Mg2+ at the microlevel. This dual-responsive probe excels in identifying infectious and metabolic calculi, compatible with endoscopic modalities and laser excitation, thereby prompting clinical visualization and diagnostic assessment.

A highly selective and sensitive peptide-based probe for the colorimetric and fluorescent detection of Fe3+, Al3+ and Cr3+ and its application in living cells imaging

A new colorimetric and fluorescent dual-responsive probe named Rb-SSC was designed and synthesized using Rhodamine B and tripeptide (SerSerCys-NH2) as raw reactants. The selective recognition properties in detecting 17 metal ions were investigated by UV–Vis spectroscopy and fluorescence spectroscopy in DMF/water (4:6, v/v, 10.0 mM HEPES, pH = 7.4), and the results showed that Rb-SSC had high selectivity fluorescence response and clear colorimetric analysis for trivalent metal ions (Fe3+, Al3+ and Cr3+). These selectivity were attributed to protonation of Rb-SSC, and the Ksp value of the trivalent ions promotes the formation of hydrolyzed H+. Additionally, the limit of detections (LODs) were found to be 27.4 nM for Fe3+, 28 nM for Al3+ and 62.3 nM for Cr3+, respectively. In addition, MTT assay and cells experiments showed that Rb-SSC has low toxicity and achieved fluorescence imaging of trivalent metal ions in living cells. What's more, the G/B ratio has a good linear relationship with the concentrations of Fe3+ based on the smartphone sensing platform (RGB values), and the limit of detection (LOD) was as low as 0.37 μM.

Development of Dual-Responsive Fluorescent Probe for Drug Screening of Diabetes Cardiomyopathy.

For specific drug research and development, a drug-screening strategy (DSS) plays an indispensable role in the biomedical field. Unfortunately, traditional strategies are complicated and insufficiently accurate due to the widely used single-target screening method. Herein, a simple dual-target-based drug-screening strategy (dt-DSS) is proposed to screen highly effective drugs by fluorescence imaging. As a proof of concept, we utilized a dual-responsive fluorescence probe to screen drugs for diabetic cardiomyopathy (DCM). We first developed and took advantage of a dual-response probe HDB to detect reactive oxygen species (ROS) and mitophagy levels in cellular starvation and high glucose models. Based on this, HDB was utilized to study the effects of different drugs in the mitophagy process caused by the high-glucose cell model for DCM. Combined with Western blotting assays, we found that Drp-1 inhibitors could fundamentally reduce mitophagy caused by the high-glucose cells model. Compared with commercial single-target antioxidant drugs, the drugs with simultaneous antioxidant capacity and Drp-1 inhibition screened by dt-DSS, such as resveratrol and icariin, could treat DCM better. Therefore, HDB as an effective tool could accurately and quickly screen high-potency drugs for DCM. We believe that this work provides an attractive strategy to explore the pathogenesis of diabetic cardiomyopathy and precisely screen for highly effective drugs.

Dual-channel fluorescent probe for discriminative detection of H2S and N2H4: Exploring sensing mechanism and real-time applications

A highly efficient system incorporates the real-time visualization of the two toxic molecules (H2S and N2H4) and the recognition of corresponding transforms using a fluorescent sensor. In this paper, a dual-responsive probe (QS-DNP) based on methylquinolinium-salicyaldehyde-2,4-dinitrophenyl was developed that can simultaneously detect H2S and N2H4 at two independent fluorescent channels without signal crosstalk. QS-DNP showed excellent anti-interference, high selectivity, outstanding water solubility, low LOD values (H2S: 51 nM; N2H4: 40 nM), low cytotoxicity, and mitochondrial localization properties. The 2,4-dinitrophenyl site was sensitive to H2S, and the CC bridge was reactive to N2H4, with strong fluorescence at 680 and 488 nm, respectively. The wavelength gap between these two channels is 192 nm; verify that there is no signal crosstalk throughout detection. By this means, the probe was used to simultaneously detect H2S and N2H4 in real soil samples, food samples, and living cells. The endogenous H2S and N2H4 were monitored in HeLa cells and investigated the mitochondria organelle of living cells with a positive charge on QS-DNP. Overall, all results emphasize that the QS-DNP probe is a powerful tool for the simultaneous detection of H2S and N2H4 and presents a potential new sensing approach.

Dual-responsive fluorescence probe for measuring HSO3− and viscosity and its application in living cells and real foods

Microenvironmental indicators in organisms drive the operation of different physiological functions. In contrast, disruption of microenvironmental homeostasis is often closely associated with various pathological processes. A novel dual-response fluorescent probe based on hemicyanine dye (HT-Bzh) was designed and synthesized for the detection of HSO3− and viscosity changes. The probe not only provides high sensitivity (limit of detection = 0.2526 μM) for the detection of HSO3− using the Michael addition reaction, but also allows the observation of fluorescence emission at 528 nm and thus the monitoring of viscosity changes through hindering of the twisted intramolecular charge transfer (TICT) mechanism. Additionally, dual-response probe has been successfully used to image living cells and detect real food samples. As a new designed tool, HT-Bzh shows excellent anti-interference capability and biocompatibility, which makes it have application potential in other biological systems and in-vivo imaging.

Dual-responsive probe and DNA interstrand crosslink precursor target the unique redox status of cancer cells.

Elevated GSH and H2O2 in cancer cells is sometimes doubted due to their contrary reactivities. Here, we construct a dual-responsive fluorescent probe to confirm the conclusion, and employ this to exploit a redox-inducible DNA interstrand crosslink (ICL) precursor. It crosslinks DNA upon activation by GSH and H2O2, affording an alternative dual-responsive strategy.

A mitochondria-targeted ratiometric NIR fluorescent probe for simultaneously monitoring viscosity and ONOO− based on two different channels in living HepG2 cells

Mitochondrial viscosity and ONOO− are involved in various pathological and physiological processes. Abnormal viscosity or irregular ONOO− concentration would disrupt the normal function of cells. Hence, we skillfully designed and synthesized a dual-responsive probe Mito-HC-TZ for the simultaneous detection of ONOO− and viscosity by different channels. 3-ethylbenzothiazolium was acted as fluorescent rotor to regulate the twisted intramolecular charge transfer (TICT) process; the C = C of 3-ethylbenzothiazolium linked to the xanthene core could be easily broken by ONOO−. Thus, the probe responded to viscosity and ONOO− by red and orange fluorescence channels, respectively. Mito-HC-TZ had high selectivity, low cytotoxicity and wide range of pH values. The results of cell imaging experiments showed the probe could be used to respectively monitor the viscosity and ONOO− level in HepG2 cells.

Oligonucleotide-Chemosensor Conjugate as a Dual Responsive Detection Platform and Its Application for Simultaneous Detection of ATP and Zn2.

Simultaneous detection, which helps understand complex physiological processes and accurately diagnose diseases, has been achieved using dual responsive probes. The dual responsive probe can ideally distinguish four cases, which are a combination of the absence and presence of two analytes, with characteristic fluorescence emissions. Owing to the demanding conditions of its development, most previous studies have focused on the simple linkage between small-molecule chemosensors that have an individual target and spectral range. In this study, a new dual responsive detection platform, oligonucleotide-chemosensor conjugate, was developed using a linkage between versatile oligonucleotide probes and small-molecule chemosensors to expand the applicable scaffold and detectable target for simultaneous detection. As a proof of concept, the ATP aptamer probe and Zn2+ chemosensor were conjugated as the levels of ATP and Zn2+ are intimately correlated in several signaling pathways and diseases. Each probe could detect an analyte independently within a conjugate probe, and simultaneous detection was also demonstrated without spectral crosstalk or interference between the receptors. In addition, the introduced cholesterol modification allowed the developed probe to detect changes in analytes on the plasma membrane of live cells through flow cytometry and confocal microscopy.

Simultaneous detection of lysosomal SO2 and viscosity using a hemicyanine-based fluorescent probe

The changes in sulfur dioxide and viscosity of lysosomes are significant indicators in physiological processes and the cell microenvironment. This study aimed to synthesize a hemicyanine-based probe for simultaneous detection of SO2 and viscosity. The probe could not only rationally detect sulfur dioxide in a semi-aqueous solution with high sensitivity (limit of detection = 0.78 μM) and fast response (within 30 s) but also monitor viscosity via fluorescence emission enhancement at 580 nm. Further, the dual-response probe was successfully used to image SO2 and viscosity in the lysosomes of living cells.

Dual-color imaging of DNA and RNA simultaneously with an aggregation/monomer-based deep-red fluorescent probe

Since many of the pivotal questions confronting chemical biology concern the interaction of more than one analyte, it is essential to investigate multiple analytes simultaneously. While commercial fluorescent dyes capable of detecting and quantitating DNA or RNA are widely used in biological research, few probes can be applied in DNA and RNA together. Distraction from each other is also a puzzling question for individual detection. Here, we have discovered a dual-responsive probe, namely, DR1, which can selectively recognize DNA by emitting out red fluorescence in the nucleus, while an entirely different stain pattern by labeling cytoplasm and nuclei with distinct cyanine fluorescence is observed owing to binding with RNA. Mechanism study found that DR1 binds to DNA in a monomer state with red fluorescence, and therefore the cyanine fluorescence may derive from its aggregated state while it binds to RNA. Then, DR1 was applied to quantify DNA and RNA contents and evaluate the effects of several inhibitors comprehensively on high-content screening platforms. Our study provided a new tool for simultaneously monitoring cellular DNA and RNA, and gaining new insights into developing dual-channel probes for multiple biomolecules.

A dual-responsive probe for the simultaneous monitoring of viscosity and peroxynitrite with different fluorescence signals in living cells.

We developed a dual-responsive fluorescent probe MC-V-P for the simultaneous detection of ONOO- and viscosity by different imaging channels. MC-V-P has high sensitivity and selectivity, and shows good stability at different pH levels. Notably, the probe has two independent fluorescence signals toward ONOO- and viscosity changes at 580 nm and 740 nm, respectively. Cell imaging experiment results demonstrated that MC-V-P exhibits low cytotoxicity and could be used to monitor viscosity and ONOO- in living HepG2 cells simultaneously.

Smart dual-response probe reveals an increase of GSH level and viscosity in Cisplatin-induced apoptosis and provides dual-channel imaging for tumor

Both glutathione (GSH) and viscosity play an important role in mitochondria. They are closely related to various physiological and pathological processes and are important biomarkers in cancer analysis. Herein, we developed the first dual responsive fluorescence probe MGV that can simultaneously detect mitochondrial GSH and viscosity. MGV is smart and shows a selective ratiometric response to GSH at 535/650 nm with a significant increase of green fluorescence. MGV can also show a distinct red fluorescence enhancement at 627 nm as viscosity increases. In addition, MGV has low cytotoxicity and good mitochondrial-targeting ability. With these features, MGV was successfully applied to image mitochondrial GSH at dual fluorescence channels and track mitochondrial viscosity changes on the red fluorescence channel. With MGV, the formation of mitochondrial bleb vesicles was observed with nystatin stimulation, and during the Cisplatin-induced apoptosis, both the level of GSH and the viscosity showed an increase. Finally, based on the dual-response to GSH and viscosity, MGV was successfully used for dual-channel imaging of cancer cells/tumors. Overall, this work provided a smart probe for GSH and viscosity and new insights/methods for apoptosis and tumor imaging.

Dual-Stimuli-Responsive Probes for Detection of Ovarian Cancer Cells and Quantification of Both pH and Enzyme Activity

Abstract Many physiological processes involve multiple coordinated chemical and/or biological events. Therefore, it is considered urgent to develop dual-responsive probes for a more comprehensive understanding of the synergistic effects between multiple analytes in complex cellular environments. In this study, we developed a dual-responsive probe βgal-BP-PMB (β-galactosyl–3,3′-dihydroxy-2,2′-bipyridyl–p-methoxybenzyl), the photoluminescence of which can be activated by β-galactosidase (β-gal) and acidic conditions. The overexpression of β-gal is an important feature of senescent and ovarian cancer cells. Single-input activatable probes for detecting β-gal activity in ovarian cancer cells can induce a false positive response from senescent cells. Because the lysosomal pH in senescent cells is increased, probe βgal-BP-PMB can be specifically activated in ovarian cancer cells, but silenced in senescent cells. Probe βgal-BP-PMB has a small molecular size, high sensitivity towards targeted stimuli and unique ratiometric properties, thereby enabling the quantification of both pH and enzyme activity. Such dual-responsive probes could earn a unique place in the field of bioimaging, where multiple analytes should be accurately and simultaneously monitored.

A dual responsive probe based on bromo substituted salicylhydrazone moiety for the colorimetric detection of Cd2+ ions and fluorometric detection of F‒ ions: Applications in live cell imaging

A dual responsive probe based on bromo substituted salicylhydrazone moiety for the colorimetric detection of Cd2+ ions and fluorometric detection of F‒ ions: Applications in live cell imaging

An oxacalix[4]arene-derived dual-sensing fluorescent probe for the relay recognition of Hg2+ and S2− ions

A rhodamine B-functionalized oxacalix[4]arene architecture has been designed as a dual-responsive probe for the sequential recognition of Hg2+ and S2− ions.

Fluorescent and colorimetric dual-response sensor based on copper (II)-decorated graphitic carbon nitride nanosheets for detection of toxic organophosphorus

An efficient and convenient detection method for organophosphorus pesticide (OP) residues is needed because of their high neurotoxicity and severe threat to food safety. OPs effectively reduce the production of thiocholine in the acetylcholinesterase/acetylthiocholine reaction by inhibiting the activity of acetylcholinesterase. Therefore, we developed a feasible and convenient fluorescent and colorimetric dual-response sensor based on the competitive complexation of Cu2+ between graphitic carbon nitride nanosheets and thiocholine for the rapid detection of OPs with high sensitivity. Malathion was used as a model OP, and a linear range of 70–800 nM with a detection limit of 6.798 nM for a fluorescent signaling platform and 2.5–25 nM with a detection limit of 1.204 nM for a colorimetric probe were attained. The constructed probe was successfully applied to determine OP in actual samples of cabbages leaves and tap water. The results indicated that the dual-response probe was reliable and sensitive to actual samples.

An unprecedented binodal (4,6)-connected Co(II) MOF as dual-responsive luminescent sensor for detection of acetylacetone and Hg2+ ions

A new Co(II) organic framework, {[Co2(L)(hfpd)(H2O)]·1.75H2O}n (1) (H4hfpd = 4,4′-(hexafluoroisopropylidene)diphthalic acid, L = 4,4′-bis(imidazol-1-yl)-biphenyl) was hydrothermally synthesized and characterized. 1 possesses an unusual (4,6)-connected layered network architecture. Fluorescence titration results present that 1 is rarely dual-responsive probe to detect acetylacetone and Hg2+ ions by luminescence quenching.

A dual-responsive probe for detecting cellular hypoxia using 19F magnetic resonance and fluorescence.

We report the first dual-responsive 19F MRI and fluorescence imaging probe for cellular hypoxia. The Cu2+-based probe exhibits no 19F MR signal and reduced fluorescence signal due to paramagnetic quenching; however, the probe turns-on in both modes following reduction to Cu+. This bimodal agent can differentiate hypoxic and normoxic cells in both modalities.

Fluorescent probes for the simultaneous detection of multiple analytes in biology.

Many of the key questions facing cellular biology concern the location and concentration of chemical species, from signalling molecules to metabolites to exogenous toxins. Fluorescent sensors (probes) have revolutionised the understanding of biological systems through their exquisite sensitivity to specific analytes. Probe design has focussed on selective sensors for individual analytes, but many of the most pertinent biological questions are related to the interaction of more than one chemical species. While it is possible to simultaneously use multiple sensors for such applications, data interpretation will be confounded by the fact that sensors will have different uptake, localisation and metabolism profiles. An alternative solution is to instead use a single probe that responds to two analytes, termed a dual-responsive probe. Recent progress in this field has yielded exciting probes, some of which have demonstrated biological application. Here we review work that has been carried out to date, and suggest future research directions that will harness the considerable potential of dual-responsive fluorescent probes.