•Artificial light-harvesting antenna materials are practically useful for the design of sensors, light-emitting diodes, and solar cells. The long-range ordered organization of energy donors and ...acceptors on the nano- to micrometer scale is crucial for efficient Förster resonance energy transfer (FRET).•The field of porous coordination polymers (PCPs, also known as metal-organic frameworks, MOFs) is rapidly growing owing to various applications including catalysis, gas storage, separations, drug delivery, magnetism, fluorescence, non-linear optics, photonics, and so on. Besides these applications, MOFs have emerged as a new class of materials for light harvesting.•Owing to the well-defined crystal structures and controllable chromophore distance via crystal engineering, coordination polymer materials provided a unique opportunity to study energy transfer.•In this review, different synthetic and post-treatment approaches to light-harvesting coordination polymer bulk materials, nanoparticles and thin film were reviewed. Optical properties, sensing applications, challenges and perspectives in this area were also discussed.•This review will be of interest to synthetic and materials chemists attempting to design light-harvesting materials and luminescent MOFs, and researchers who are using MOF as a platform for applications such as chemical and biological sensing, medical imaging, and electro-optical devices.
This review highlights the recent progress of bulk and nanoscale coordination polymer (CP) materials for energy transfer. Artificial light-harvesting materials with efficient energy transfer are practically useful for a variety of applications including photovoltaic, white emitting devices, and sensors. In the past decades CP (aka Metal-organic framework, MOF) has experienced rapid development due to a multitude of applications, including catalyst, gas storage and separations, non-linear optics, luminescence, and so on. Recent research has shown that CP is a very promising light-harvesting platform because the energy transfers can occur between different ligands, from ligand to metal centers, or from MOF skeleton to guest species. This review comprehensively surveyed synthetic approaches to light-harvesting CPs, and post functionalization. Sensing applications and achievements in energy-transfer CP nanoparticles and thin films were also discussed.
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•Recent advances of coordination-based CPL emitters are reviewed.•The rational design strategies for CPL-active complexes are summarized.•The applications of CPL in sensing metal ions ...and nonmetal analytes are addressed.•This review provides valuable guidelines for further development of CPL-active complexes.
Chiral systems emitting circularly polarized luminescence (CPL) have great potential in practical applications including but not limiting to 3D optical displays, information storage, advanced security materials and chiroptical sensors. CPL-active coordination compounds not only have relatively smaller molecular size than supramolecular systems but also exhibit higher CPL level than purely organic small molecules, which enables them to serve as favorable CPL-emitting materials for the expanded range of applications. Here, we discuss the recent advances of coordination-based CPL-active systems, including boron complexes and metal complexes, focusing on the summary and discussion of design strategies, as well as the applications in chiroptical sensing.
Light has been widely used for cancer therapeutics such as photodynamic therapy (PDT) and photothermal therapy. This paper describes a strategy called enzyme-enhanced phototherapy (EEPT) for cancer ...treatment. We constructed a nanoparticle platform by covalent conjugation of glucose oxidase (GOx) to small polymer dots, which could be persistently immobilized into a tumor. While the malignant tumors have high glucose uptake, the GOx efficiently catalyzes the glucose oxidation with simultaneous generation of H2O2. Under light irradiation, the in situ generated H2O2 was photolyzed to produce hydroxyl radical, the most reactive oxygen species, for killing cancer cells. In vitro assays indicated that the cancer cells were destroyed by using a nanoparticle concentration at 0.2 μg/mL and a light dose of ∼120 J/cm2, indicating the significantly enhanced efficiency of the EEPT method when compared to typical PDT that requires a photosensitizer of >10 μg/mL for effective cell killing under the same light dose. Furthermore, remarkable inhibition of tumor growth was observed in xenograft-bearing mice, indicating the promise of the EEPT approach for cancer therapeutics.
Abstract
In contrast to the conventional passive reaction to analytes, here, we create a proof-of-concept nanochannel system capable of on-demand recognition of the target to achieve an unbiased ...response. Inspired by light-activatable biological channelrhodopsin-2, photochromic spiropyran/anodic aluminium oxide nanochannel sensors are constructed to realize a light-controlled inert/active-switchable response to SO
2
by ionic transport behaviour. We find that light can finely regulate the reactivity of the nanochannels for the on-demand detection of SO
2
. Pristine spiropyran/anodic aluminium oxide nanochannels are not reactive to SO
2
. After ultraviolet irradiation of the nanochannels, spiropyran isomerizes to merocyanine with a carbon‒carbon double bond nucleophilic site, which can react with SO
2
to generate a new hydrophilic adduct. Benefiting from increasing asymmetric wettability, the proposed device exhibits a robust photoactivated detection performance in SO
2
detection in the range from 10 nM to 1 mM achieved by monitoring the rectified current.
Subtle modification of molecular structure can play a crucial role in determining photophysical properties and stimuli-responsive behavior. Herein, four aggregation-induced emission (AIE)-active ...tetraphenylethylene-based positional isomers S1, S2, S3 and S4 have been designed and synthesized. S2 and S4 exhibit higher fluorescence quantum yield (ΦFL) as compared to S1 and S3, respectively, which was due to the positional isomerism. In addition, all four isomers exhibit reversible mechanofluorochromic (MFC) behavior with mechanical-induced emission enhancement (MIEE), which was studied using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). S1 and S2 display better MFC activities, compared with S3 and S4, due to opened phenylimidazole presenting a more twisted conformation. Moreover, they can detect picric acid (PA) in a highly selective and sensitive manner in aqueous media, due to the excellent proton-binding property of the imidazole group, which was verified by 1H NMR spectra and supported by theoretical calculations. Overall, tetraphenylethylene containing arylimidazole derivatives described herein will efficiently expand the development of design principles to supply diverse multifunctional tools for material science and material engineering.
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•A series of isomers were synthesized by combination of TPE and arylimidazole units.•Isomers exhibit MFC behavior with mechanical-induced emission enhancement.•Isomers can detect PA in a highly sensitive manner in aqueous medium.
Semiconducting polymers with specific absorption are useful in various applications, including organic optoelectronics, optical imaging, and nanomedicine. However, the optical absorption of a ...semiconducting polymer with a determined structure is hardly tunable when compared with that of inorganic semiconductors. In this work, we show that the optical absorption of polymer nanoparticles from one conjugated backbone can be effectively tuned through judicious design of the particle morphology and the persistence length of polymers. Highly absorbing near-infrared (NIR) polymers based on diketopyrrolopyrrole-dithiophene (DPP-DT) are synthesized to have different molecular weights (MWs). The DPP-DT polymer with a large molecular weight and high persistence length exhibited remarkably high optical absorption with a peak mass extinction coefficient of 81.7 L g−1 cm−1, which is one of the highest value among various photothermal agents reported to date. Particularly, the polymer nanoparticles with different sizes exhibit broadly tunable NIR absorption peaks from 630 to 811 nm. The PEGylated small polymer dots (Pdots) show good NIR light-harvesting efficiency and high non-radiative decay rates, resulting in a relatively high photothermal conversion efficiency in excess of 50%. Thus, this Pdot-based platform can serve as promising photothermal agents and photoacoustic probes for cancer theranostics.
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Optical methods such as absorptiometry, fluorescence, and surface plasmon resonance have long been explored for sensing glucose. However, these schemes have not had the clinical success of ...electrochemical methods for point-of-care testing because of the limited performance of optical sensors and the bulky instruments they require. Here, we show that an ultrasensitive optical transducer can be used for wireless glucose monitoring via a smartphone. The optical transducer combines oxygen-sensitive polymer dots (Pdots) with glucose oxidase that sensitively detect glucose when oxygen is consumed in the glucose oxidation reaction. By judicious design of the Pdots with ultralong phosphorescence lifetime, the transducer exhibited a significantly enhanced sensitivity by 1 order of magnitude as compared to the one in a previous study. As a result, the optical images of subcutaneous glucose level obtained with the smartphone camera could be utilized to clearly distinguish between euglycemia and hyperglycemia. We further developed an image processing algorithm and a software application that was installed on a smartphone. Real-time dynamic glucose monitoring in live mice was demonstrated with the smartphone and the implanted Pdot transducer.
Ultrasound (US)-activated sonodynamic therapy (SDT) stands for a distinct antitumor modality because of its attractive characteristics including intriguing noninvasiveness, desirable safety, and high ...tissue penetration depth, which, unfortunately, suffers from compromised therapeutic efficacy due to cancer cell-inherent adaptive mechanisms, such as glutathione (GSH) neutralization response to reactive oxygen species (ROS), and glutamine addictive properties of tumors. In this work, we developed a biological sonosensitive platelet (PLT) pharmacytes for favoring US/GSH-responsive combinational therapeutic of glutamine deprivation and augmented SDT. The amino acid transporter SLC6A14 blockade agent α-methyl-DL-tryptophan (α-MT)-loaded and MnO2-coated porphyrinic metal-organic framework (MOF) nanoparticles were encapsulated in the PLTs through the physical adsorption of electrostatic attraction and the intrinsic endocytosis of PLTs. When the sonosensitive PLT pharmacytes reached tumor sites through their natural tendencies to TME, US stimulated the PLTs-loaded porphyrinic MOF to generate ROS, resulting in morphological changes of the PLTs and the release of nanoparticles. Subsequently, intracellular high concentration of GSH and extracellular spatio-temporal controlled US irradiation programmatically triggered the release of α-MT, which enabled the synergistically amplified SDT by inducing amino acid starvation, inhibiting mTOR, and mediating ferroptosis. In addition, US stimulation achieved the targeted activation of PLTs at tumor vascular site, which evolved from circulating PLTs to dendritic PLTs, effectively blocking the blood supply of tumors through thrombus formation, and revealing the encouraging potential to facilitate tumor therapeutics.
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•Live sonosensitive platelet bio-nano platform were engineered to achieve US/GSH-responsive drug delivery.•US stimulation achieved targeted activation of PLTs at tumor vascular sites to facilitate tumor therapy.•Intervening glutamine metabolism heightened SDT sensitivity.
The chelating gadolinium-complex is routinely used as magnetic resonance imaging (MRI) -contrast enhancer. However, several safety issues have recently been reported by FDA and PRAC. There is an ...urgent need for the next generation of safer MRI-contrast enhancers, with improved local contrast and targeting capabilities. Cerium oxide nanoparticles (CeNPs) are designed with fractions of up to 50% gadolinium to utilize the superior MRI-contrast properties of gadolinium. CeNPs are well-tolerated in vivo and have redox properties making them suitable for biomedical applications, for example scavenging purposes on the tissue- and cellular level and during tumor treatment to reduce in vivo inflammatory processes. Our near edge X-ray absorption fine structure (NEXAFS) studies show that implementation of gadolinium changes the initial co-existence of oxidation states Ce
and Ce
of cerium, thereby affecting the scavenging properties of the nanoparticles. Based on ab initio electronic structure calculations, we describe the most prominent spectral features for the respective oxidation states. The as-prepared gadolinium-implemented CeNPs are 3-5 nm in size, have r
-relaxivities between 7-13 mM
s
and show clear antioxidative properties, all of which means they are promising theranostic agents for use in future biomedical applications.
•Coordination-based molecular nanomaterials with diverse structures and properties are discussed comprehensively.•Molecular nanomaterials bridge the gap between small molecules and conventional ...nanomaterials.•The bioimaging and sensing applications of coordination-based molecular nanomaterials are summarized and discussed in detail.•Therapeutic applications of coordination-based molecular nanomaterials are summarized and discussed in detail.•The challenges and perspectives of molecular materials are discussed.
Molecular nanomaterials built with well-defined chemical structures, accurate molecular weights and high synthetic reproducibility, have emerged as an exciting new branch of nanomaterials. Meaningfully, they perfectly fill the gap between small molecules and conventional nanomaterials. Nevertheless, coordination-based molecular nanomaterials are especially attractive due to their diverse structures and multifunctionalities combining merits of both organic components and metal ions. This review highlights recent progresses of coordination-based molecular nanomaterials mainly involving biomedically relevant applications, such as biosensing, bioimaging and therapy. Three typical coordination-based molecular nanomaterials were emphasized: (1) Organometallic carborane nanoclusters showed high amount of boron, as well as varieties of optical properties by the incorporation between metals/metal complexes and carborane, make a great contribution to bioimaging and boron neutron capture therapy. (2) Atomically precise metal nanoclusters cascading metals as a whole, thus possessing intriguing structures and diverse optical properties, which are superior in biosensing, bioimaging and phototherapy. (3) Metal-organic nanocages assembled as containers play an important role in biosensing and biomolecular delivery because of host–guest interactions, and they also display excellent DNA binding for antitumor. Finally, the current challenges and perspectives for the further trend are also discussed. The overview will lead timely recognition of coordination-based molecular nanomaterials and hopefully stimulate their fast development.
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