Off-on Fluorescence Research Articles

Alloyed AuFeZnSe quantum dots@gold nanorod nanocomposite as an ultrasensitive and selective plasmon-amplified fluorescence OFF-ON aptasensor for arsenic (III)

According to documented reports, more than 200 million people across the globe are exposed to arsenic (As) contamination at levels above the World Health Organization (WHO) guideline limit of 10 μg/L. In this work, a novel fluorescence OFF-ON ultrasensitive aptasensor was developed for As (III). To construct the fluorescence aptasensor, AuFeZnSe alloyed quantum dots (QDs) were newly synthesized and surface-coated with amphiphilic polymers (Amp-P) to render the QDs biocompatible and stable. Thereafter, cationic gold nanorods (AuNRs) were electrostatically bonded to the Amp-P-QDs to form an Amp-P-QDs-AuNR nanocomposite which switched OFF the fluorescence of the bound QDs. Thiolated anti-As (III) DNA aptamer (Apt) was thereafter assembled on the Amp-P-QDs-AuNR surface to form a Amp-P-Apt-QDs-AuNR probe. The affinity binding interaction between the targeted As (III) concentration and the Apt, triggered localized surface plasmon resonance (LSPR) from AuNRs to amplify the fluorescence intensity signal, thereby switching ON the fluorescence of the bound Amp-P-QDs. Comparison of the Amp-P-Apt-QDs and the Amp-P-Apt-QDs-AuNR probes, showed that the presence of AuNR enhanced the fluorescence of the bound Amp-P-QDs for As (III) by as much as 230%, representing an ∼20-fold increase over the Amp-P-Apt-QDs probe without AuNRs. Under optimum conditions, As (III) was selectively and quantitatively detected with ultra-high sensitivity. The linear range was 0.01–100 μg/L, while the obtained detection limit of 0.01 μg/L (69.12 pM) was 1000 times lower than the WHO recommended limit. We successfully applied the Amp-P-Apt-QDs-AuNR probe to detect As (III) in environmental and biological samples with analytical recoveries from ∼93 to 105%.

On-off-on fluorescence detection for biomolecules by a fluorescent cage through host-guest complexation in water

Detection of nucleoside derivatives has paramount importance because they are the essential biomolecular units for all life. Herein, we report a host-guest approach by using a fluorescent tetraphenylethene-based octacationic cage as host and 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) as guest and fluorescent indicator to form non-fluorescent 1:1:1 host-(endo-exo)guest complex in water. This new host-(endo-exo)guest complex can be successfully used for detecting nucleosides (e.g., ATP and GTP), DNA (e.g., sm-DNA), and antibiotics (e.g., Penicillin G) with off-on fluorescence response via a competitive host-guest exchange with HPTS as exo-guest in water. Furthermore, this on-off-on fluorescent host-guest complex is also used for cell imaging based on ATP concentration in HeLa cells. Therefore, this study not only provides insight into the construction of a supramolecular probe with on-off-on fluorescence via host-guest complexation and exchange in solution, but also realizes a universal method for detecting and monitoring biomolecules.

Rational design of shortwave infrared (SWIR) fluorescence probe: Cooperation of ICT and ESIPT processes for sensing endogenous cysteine

Cysteine is well-known to be an important biothiol and related to many diseases. However, the in vivo detection of endogenous cysteine still suffers from lacking small-molecule fluorophores with both excitation and emission in the near-infrared (650-900 nm)/shortwave-infrared region. Herein, we report a molecular engineering strategy for shortwave infrared (SWIR, 900-1700 nm) sensing of cysteine, which integrated an excited-state intermolecular proton transfer (ESIPT) building block into the intramolecular charge transfer (ICT) scaffold. The obtained novel fluorophore SH-OH displays a maximum absorption at the NIR region, and emission at the SWIR region. We introduce the cysteine-recognition moiety to SH-OH structure, and demonstrate sensing of endogenous cysteine in living animals, using the SWIR emission as a reliable off-on fluorescence signal. This fluorophore design strategy of cooperation of ICT and ESIPT processes expands the in vivo sensing toolbox for accurate analysis in clinical applications.

An Integration Strategy to Develop Dual-State Luminophores with Tunable Spectra, Large Stokes Shift, and Activatable Fluorescence for High-Contrast Imaging

An Integration Strategy to Develop Dual-State Luminophores with Tunable Spectra, Large Stokes Shift, and Activatable Fluorescence for High-Contrast Imaging

Real-time imaging mitochondrial viscosity dynamic during mitophagy mediated by photodynamic therapy

Photodynamic therapy has been generally developed and approved as a promising theranostic technique in recent years, which requires photosensitizers to bear high efficiency of reactive oxygen species production, precisely targeting ability and excellent biocompatibility. The real-time monitoring the microenvironments such as viscosity dynamic involved in mitophagy mediated by photodynamic therapy is significantly important to understand therapeutic process but barely reported. In this work, a pyridinium-functionalized triphenylamine derivative, (E)-4-(2-(4'-(diphenylamino)-[1,1′-biphenyl]-4-yl)vinyl)-1-methylpyridin-1-ium iodide (Mito-I), was exploited as photosensitizer for mitochondria-targeted photodynamic therapy and as fluorescent probe for imaging the mitochondrial viscosity dynamic during mitophagy simultaneously. The results indicated that the additional phenyl ring in Mito-I was beneficial to promote its efficiency of singlet oxygen production. The excellent capability of targeting mitochondria and singlet oxygen generation allowed Mito-I for the specifically mitochondria-targeted photodynamic therapy. Moreover, Mito-I displayed off-on fluorescence response to viscosity with high selectivity and sensitivity. The observed enhancement in fluorescence intensity of Mito-I revealed the increasingly mitochondrial viscosity during mitophagy mediated by the photodynamic therapy of Mito-I. As a result, this work presents a rare example to realize the mitochondria-targeting photodynamic therapy as well as the real-time monitoring viscosity dynamic during mitophagy, which is of great importance for the basic medical research involved in photodynamic therapy.

Trivalent Cations Detection of Magnetic-Sensitive Microcapsules by Controlled-Release Fluorescence Off-On Sensor.

A pyrene-based derivative, 2-((pyrene-1-ylmethylene)amino)ethanol (PE) nanoparticle, was encapsulated via water-in-oil-in-water (W/O/W) double emulsion with the solvent evaporation method by one-pot reaction and utilized as a fluorescence turn-on sensor for detecting Fe3+, Cr3+, and Al3+ ions. Magnetic nanoparticles (MNPs) embedded in polycaprolactone (PCL) were used as the magnetic-sensitive polyelectrolyte microcapsule-triggered elements in the construction of the polymer matrix. The microcapsules were characterized by ultraviolet–visible (UV–Vis) and photoluminescence (PL) titrations, quantum yield (Φf) calculations, 1H nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and superconducting quantum interference device magnetometry (SQUID) studies. This novel responsive release of the microcapsule fluorescence of the turn-on sensor for detecting trivalent cations was due to the compound PE and the MNPs being incorporated well within the whole system, and an effective thermal and kinetic energy transfer between the core and shell structure efficiently occurred in the externally oscillating magnetic field. The magnetic-sensitive fluorescence turn-on microcapsules show potential for effective metal ion sensing in environmental monitoring and even biomedical applications. Under the optimal controlled-release probe fluorescence conditions with high-frequency magnetic field treatment, the limit of detection (LOD) reached 1.574–2.860 μM and recoveries ranged from 94.7–99.4% for those metals in tap water.

Rational construction of a reversible arylazo-based NIR probe for cycling hypoxia imaging in vivo

Reversible NIR luminescent probes with negligible photocytotoxicity are required for long-term tracking of cycling hypoxia in vivo. However, almost all of the reported organic fluorescent hypoxia probes reported until now were irreversible. Here we report a reversible arylazo-conjugated fluorescent probe (HDSF) for cycling hypoxia imaging. HDSF displays an off-on fluorescence switch at 705 nm in normoxia-hypoxia cycles. Mass spectroscopic and theoretical studies confirm that the reversible sensing behavior is attributed to the two electron-withdrawing trifluoromethyl groups, which stabilizes the reduction intermediate phenylhydrazine and blocks the further reductive decomposition. Cycling hypoxia monitoring in cells and zebrafish embryos is realized by HDSF using confocal imaging. Moreover, hypoxic solid tumors are visualized and the ischemia-reperfusion process in mice is monitored in real-time. This work provides an effective strategy to construct organic fluorescent probes for cycling hypoxia imaging and paves the way for the study of cycling hypoxia biology.

Sensitive Cu2+ detection by reversible on-off fluorescence using Eu3+ complexes in SiO2, in chitosan/polyethylene oxide nanofibers

Trace amounts of heavy metal ions in the human body are essential for maintaining health. However, heavy metal ion excess or deficiency causes toxicity or disease. This study examines the sensitivity of luminescent europium complexes for the detection of Cu2+. Here, Eu3+ is complexed with1,10-phenanthroline (phen) and 4,4′,4-trimethyltriphenylamine (TTA) to form luminescent [Eu3+(TTA)3phen] complexes, encapsulated in silica (SiO2) nanoparticles. The silica nanoparticles are then formed into a composite with a blend of chitosan and polyethylene oxide (PEO), to make electrospun nanofibers. The combination of Eu3+ complexes with SiO2 nanoparticles doped in chitosan enhances the fluorescence performance. Photophysical measurements show that when the Cu2+ concentration is 100 μmol/L, the fluorescence of the composite chitosan nanofibers can be quickly and sensitively quenched, and that concentrations as low as 10 μmol/L Cu2+ can be detected. Furthermore, the use of chitosan and PEO to prepare the material makes these new fluorescence-based copper sensing materials suitable for Cu2+ detection in biological systems.

Fe3+ sensitivity fluorescence sensor from β-cyclodextrin-enhanced Eu3+ luminescence aggregates

In this work, novel β-cyclodextrin-enhanced Eu3+ luminescence aggregates (CELAs) with bright red fluorescence of Eu3+ are prepared. These CELAs exhibit the quick response and highly selective sensitivity at the concentration of 50 µM Fe3+. A series of ligands (such as TTA, phen, β-cyclodextrin) sensitizes the luminescence of Eu3+ (the “antenna effect”), and metal ions–ligands interactions can differentially alter the antenna effect of ligands toward Eu3+. Addition of EDTA to chelate Fe3+ restores the fluorescence, indicating that the fluorescence quenching in the presence of Fe3+ is reversible. This research provides that CELAs integrate these merits of superior lanthanide fluorescence and the amphiphilia property of β-cyclodextrin (β-CD). It is a unique system with enhancement Eu3+ luminescence in ethanol–water system and will be applied for aqueous solution detection sensor with high selectivity and reversibility for Fe3+. On the other hand, the on-off fluorescence property of the CELAs is convenient for environmental detection system.

Real-Time Monitoring Mitochondrial Viscosity during Mitophagy Using a Mitochondria-Immobilized Near-Infrared Aggregation-Induced Emission Probe.

Mitophagy plays a crucial role in maintaining intracellular homeostasis through the removal of dysfunctional mitochondria and recycling their constituents in a lysosome-degradative pathway, which leads to microenvironmental changes within mitochondria, such as the pH, viscosity, and polarity. However, most of the mitochondrial fluorescence viscosity probes only rely on electrostatic attraction and readily leak out from the mitochondria during mitophagy with a decreased membrane potential, thus easily leading to an inaccurate detection of viscosity changes. In this work, we report a mitochondria-immobilized NIR-emissive aggregation-induced emission (AIE) probe CS-Py-BC, which allows for an off-on fluorescence response to viscosity, thus enabling the real-time monitoring viscosity variation during mitophagy. This system consists of a cyanostilbene skeleton as the AIE active core and viscosity-sensitive unit, a pyridinium cation for the mitochondria-targeting group, and a benzyl chloride subunit that induces mitochondrial immobilization. As the viscosity increased from 0.903 cP (0% glycerol) to 965 cP (99% glycerol), CS-Py-BC exhibited an about 92-fold increase in fluorescence intensity at 650 nm, which might be attributed to the restriction of rotation and inhibition of twisted intramolecular charge transfer in a high viscosity system. We also revealed that CS-Py-BC could be well immobilized onto mitochondria, regardless of the mitochondrial membrane potential fluctuation. Most importantly, using CS-Py-BC, we have successfully visualized the increased mitochondrial viscosity during starvation or rapamycin-induced mitophagy in real time. All these features render CS-Py-BC a promising candidate to investigate mitophagy-associated dynamic physiological and pathological processes.

An aroylhydrazone-containing diarylethene derivative derived chemosensor for colorimetric and fluorimetric dual sensing Cu2+

A diarylethene derivative with an aroylhydrazone unit was designed and synthesized as a colorimetric and fluorimetric dual responsive sensor for Cu2+ with high selectivity and rapid response. Connecting 7-diethylamino-3-hydrazide-coumarin moiety and 2-pyridyl-containg diarylethene provided an intramolecular charge transfer (ICT) system with affluent binding site (N^N^O), which was developed for the selective and sensitive detection of Cu2+ by dual colorimetric and fluorimetric responses. A clear Cu2+-induced ratiometric colorimetric sensor with color change from light yellow to orange red and on-off fluorescence with fluorescence color change from bright cyan to deep teal was constructed. At the same time, colorimetric and fluorimetric responses to Cu2+ were both achieved at the photostationary state. Based on the obvious color change, the sensor was used for the fabrication of test strips that can be used as the standard cards for detecting Cu2+. This study is expected to facilitate and broaden the application of diarylethene derivative in tracing Cu2+ in future work.

A selective fluorescent probe for gadoliniumIII in water based on a PdII-preorganized chromone-receptor.

The synthesis, solution studies, photochemical properties and the X-ray structure of a chromone based fluorescent PdII complex are reported. The ligand contains two chromone units linked as side arms to an ethylenediamine moiety; in the PdII complex the metal ion preorganizes the two hydroxychromone units forming a rigid structure with a negatively charged pocket formed by four oxygen atoms that is able to interact with hard metal cations, such as ions, giving rise to stable bimetallic complexes. Upon interaction with LaIII and GdIII, in particular, the emission intensity at 423 nm increases by a factor of 2 and 8, respectively, while the other rare earth ions quench the fluorescence. Spectrofluorimetric studies on real matrices showed the possibility to use this system as a selective fluorescence probe to detect and trace the presence of Gadolinium in environmental water acting as an OFF-ON chemosensor, with a LOD of 0.4 ppm and a LOQ of 1.2 ppm.

Glutathione Capped Gold Nanoclusters-Based Fluorescence Probe for Highly Sensitive and Selective Detection of Transferrin

In this study, we developed a novel approach for the first time to detect transferrin based on the glutathione capped gold nanoclusters (GSH-AuNCs). The GSH-AuNCs were prepared in a simple process by using GSH as a stabilizer and reduced reagent. Most metal ions could quench the fluorescence of gold nanoclusters. Ferric ions could also make the fluorescence of GSH-AuNCs quench. Furthermore, because of the more important coordination between ferric ions and transferrin, the fluorescence was considerably increased when transferrin was added to the GSH-AuNCs-Fe3+ system. Based on this principle, we have established a new fluorescence method to determine transferrin with high selectivity. The detection limit of transferrin was calculated to be 0.06 µM in the linear range of 0.2-1.0 µM. Moreover, the mechanism of the fluorescence off-on of this method was also investigated. The proposed method has been shown to have outstanding sensing capability and has been successfully used to determine the transferrin in rat serum samples.

A bifunctional molecule-based strategy for the development of theranostic antibody-drug conjugate.

Antibody-drug conjugates (ADCs) are being developed worldwide with the potential to revolutionize current cancer treatment strategies. Developing novel theranostic ADCs with therapeutic utility and imaging capability is an attractive and challenging subject that promises advances in the field of personalized medicine. In this work, we propose a bifunctional molecule-based strategy for the development of theranostic ADCs.Methods: We developed a theranostic ADC consisting of the anti-Her2 antibody Mil40, monomethyl auristatin E (MMAE) as the active payload, and a 7-amino-3-hydroxyethyl-coumarin (7-AHC)-based dipeptide linker, which functions as a novel bifunctional fluorescence probe that allows self-elimination cleavage in the presence of cathepsin B for payload release and fluorophore activation. The on-off fluorescence properties and the antitumor effect in vitro and in vivo were investigated.Results: A 48-fold fluorescence enhancement was observed within 1 h when the 7-AHC-based linker was exposed to cathepsin B. Cleavage upon exposure to cathepsin B allows MMAE and fluorophore intracellular release and the monitoring of MMAE distribution using confocal microscopy. Additionally, the newly developed ADC retains the advantages of traditional p-aminobenzyloxycarbonyl-containing ADCs, such as good stability (t1/2 > 7 days) and high activity in vitro (IC50 = 0.09-3.74 nM). Importantly, the theranostic ADC exhibited the equivalent antitumor efficacy to the marketed ADC T-DM1 in the classic breast cancer model.Conclusion: We suggest that the present strategy can be universally applied in all p-aminobenzyloxycarbonyl-containing ADCs. Overall, theranostic ADCs may play a role in developing new theranostic systems and promoting personalized medicine research.

A novel long-wavelength off-on fluorescence probe for nitroreductase analysis and hypoxia imaging

Hypoxia is one of the most important features of various diseases including solid tumors. It is of significant clinical importance for hypoxia analysis in tumors, and the analysis of hypoxia can be moved away to the indirect detection of nitroreductase. Various fluorescence methods have been developed for the analysis of nitroreductase and tumor hypoxia due to their simplicity, non-invasiveness and excellent spatial-temporal resolution. Here, we synthesized a multifunctional fluorophore, which possesses larger π-conjugation structure, leading to the red-shift of absorption and fluorescence emission to long-wavelength region. This fluorophore (RCOH) can be further used to prepare the off-on hypoxia probe (RCO-NTR) by introducing the electron withdrawing group of nitrobenzyl, leading to the quenching of fluorescence emission through an electron transfer process. After reaction with NTR accompanied by NADH as an electron donor, the nitro group in the RCO-NTR probe can be reduced and then the RCOH fluorophore can be released through rearrangement and elimination, leading to the enhancement of fluorescence signal. Thus, the prepared RCO-NTR probe can be used for nitroreductase analysis, which can be further used for hypoxia imaging at both cellular and animal levels.

Smart carbon dots as chemosensor for control of water contamination in organic media

A novel nanoprobe was synthesized by functionalizing gluthatione/citric acid–carbon dots (CDs) with a benzo-isoquinolin-based molecule, methyl 3-(4-(2-(5-((methylsulfonyl)oxy)pentyl)-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)piperazin-1-yl)propanoate (water chemosensor, WCS), to detect trace amounts of water in non-aqueous media via on-off fluorescence. The design and synthesis of the free molecule WCS and the functionalized nanoprobe (CD-WCS) are described in detail and as well as their full characterization by different spectroscopic methods. WCS was found to be an excellent indicator of pH in aqueous media and exhibited, in solvents of different polarity, solvatochromic behaviour. On the other hand, the modified fluorescence intensity of CD-WCS was found to be an excellent indicator for water in non-aqueous media (organic solvents and oil-based lubricants). In these media, CD-WCS showed weak fluorescence intensity due to a photoinduced electron transfer (PET) process. Sequential addition of trace amount of water led to revival of CD-WCS fluorescence intensity. The fluorescence on-off mechanisms are proposed for WCS in aqueous media as well as for CD-WCS in non-aqueous media. The analytical performance characteristics of CD-WCS showed a limit of detection for water of 0.00021 % (v/v) in toluene and 0.00014 % v/v in base-oil lubricant. The potential application of CD-WCS as chemosensor of water contamination in oil-based lubricants as well as green anti-wear/anti-friction lubricant additive are outlined.

P.505 Trustworthiness judgments are associated with paranoia and social functioning

Novel, one bay-substituted perylene bisanhydride (6) and two bay-substituted perylene bisimides (7, 10) have been successfully synthesized with a large and swallow tail type, 2-decyl-1-tetradecanoyl substituents at the bay area (1 and 7 positions). The non-bay-substituted perylene bisimides with the same N-substituents were prepared as model compounds (3, 9) for comparison. Absorption and fluorescence, electrochemical, spectroelectrochemical, morphological properties of the compounds were investigated, and then, density functional theory (DFT) simulations were conducted. The compounds 6, 7 and 10 have shown J-aggregated featureless, very broad absorbance through the UV–vis-NIR region with a strong fluorescence quenching attributed to efficient intramolecular electron transfer from electron donor 2-decyl-1-tetradecanoyl substituent to PDI acceptor and scaffolds allow π–π intermolecular interactions, induced molecular aggregation. The absolute positions of LUMO and HOMO values for 3, 9, 6, 7 and 10 in solutions were −3.91/−6.09 eV, −3.93/−6.08 eV, −4.02/−5.90 eV, −4.02/−5.91 eV and −4.02/−5.97 eV, respectively. The onset reduction potential of compounds 6, 7 and 10 are lower than those of compounds 3 and 9. Similarly, the onset oxidation potential values of the compounds 6, 7 and 10 are smaller than those of the non-bay-substituted perylene dyes 3 and 9. The synthesized compounds (3 with 7; 9 with 10) can be exploited as an off-on fluorescence probes for photonic applications.

Poly(N-Isopropylacrylamide)-Functional Silicon Nanocrystals for Thermosensitive Fluorescence Cellar Imaging.

Silicon nanocrystals (Si NCs) have received surging interest as a type of quantum dot (QD) due to the availability of silicon in nature, tunable fluorescence emission properties and excellent biocompatibility. More importantly, compared with many group II–VI and III–V based QDs, they have low toxicity. Here, thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-functional Si NCs were firstly prepared for thermoresponsive detection of cancer cells. Si NCs were prepared under normal pressure with excellent water solubility. Then folic acid was bonded to the silicon nanocrystals through the reaction of amino and carboxyl groups for specific recognition of cancer cells. The folic-acid-modified silicon crystals (Si NCs-FA) could be modified by a one-pot copolymerization process into PNIPAAm nanospheres during the monomer polymerization process (i.e., Si NCs-FA-PNIPAAm) just by controlling the temperature below the lower critical solution temperature (LCST) and above the LCST. The results showed that the Si-FA-PNIAAm nanospheres exhibited not only reversible temperature-responsive on-off fluorescence properties, but also can be used as temperature indicators in cancer cells.

A pH-Sensing Fluorescent Metal-Organic Framework: pH-Triggered Fluorescence Transition and Detection of Mycotoxin.

Due to its great relevance to environmental, biological, and chemical processes, the precise detection of pH or acidic/basic species is an ongoing and imperative need. In this context, pH-sensitive luminescent systems are highly desired. We reported a three-dimensional Zn(II) MOF synthesized from a bipyridyl-tetracarboxylic ligand and composed of 4-fold interpenetrated diamond frameworks. Because the steric hindrance in the ligand prevents metal coordination with the pyridyl group, the MOF features free basic N sites accessible to the small H+ ions, which renders pH responsivity. The aqueous dispersion exhibits an abrupt, high-contrast, and reversible on-off fluorescence transition in the narrow pH range of 5.4-6.2. The sensitive bistable system can be used for the precise monitoring of pH within the range and for use as a pH-triggered optical switch. The responsive mechanism through pyridyl protonation is collaboratively supported by data fitting, absorption spectra, and molecular orbital calculations. In particular, spectral and theoretical analyses reveal the destruction of n → π* transitions and the appearance of intramolecular charge-transfer transitions upon pyridyl protonation. Moreover, by virtue of the pH-responsive fluorescence, the MOF shows appealing sensing performance for the detection of 3-nitropropionic acid, a major mycotoxin in moldy sugar cane.

Alkaline‐Earth Metal Ion Turn‐On Circularly Polarized Luminescence and Encrypted Selective Recognition of AMP

AbstractCircularly polarized luminescence (CPL) provides fundamental insights into the chiral structural information of luminescent materials at their excited states, thus contributing to the possibility of encrypting both chirality and luminescence information into functional materials for multi‐purpose applications such as smart chiroptical devices and encrypted recognition systems. Here, by coordination of alkali‐earth metal ions with a chiral histidine‐functionalized amphiphile (methyl (E)‐(2‐styrylthiazole‐4‐carbonyl)‐l‐histidinate, abbreviated as STH), both fluorescence (FL), and CPL signals are encoded into the STH metal complexes. Impressively, the CPL‐active STH/Mg2+ complex features an encrypted selective recognition ability of adenosine monophosphate (AMP) among the three types of adenosine phosphates (ATP, ADP, and AMP), while FL signals cannot distinguish them. It is found that the trans‐cis photo‐isomerization of styrene moiety in the building block leads to significant switching between different molecular configurations, FL and CPL signals, producing a high‐efficiency ON–OFF FL and CPL switch. Although FL switch shows negligible discrimination for three types of adenosines, the CPL‐ON state can efficiently recognize AMP at physiological concentration range, which highlights its prospect as a smart CPL probe toward chiral bioactive compounds.