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The use of cheap and safe near-infrared (NIR) light is still the subject of intense research efforts but remains a huge challenge due to the associated low photon energy (wavelength from 0.78 to 2.5 µm). In this study, a series of 17 NIR dyes mainly based on a well-established cyanine scaffold is proposed. Remarkably, 11 of them were never synthesized before. Markedly, noncharged structures, negatively charged cyanine bearing Na+ as counter cation, and positively charged cyanines bearing (B(Ph)4−) or (I−) as counter anions were examined as promising NIR light photoinitiating systems. Excellent photoinitiating abilities were found for some reported dyes when used in combination with iodonium salt and amine. Markedly, photothermal effects with a huge heater behavior were also observed for different NIR dye structures. Interestingly, the synthesis of interpenetrating polymer networks (IPNs, e.g., for the polymerization of acrylate/epoxy monomer blends) can also be carried out upon NIR light with the proposed systems.

Photovoltaic retinal prosthesis is designed to restore sight in patients who lost central vision due to atrophic AMD. Subretinal pixels convert pulsed NIR light projected from augmented-reality glasses into electric current, stimulating the nearby inner retinal neurons. In patients with geographic atrophy, such prosthetic central vision coexists with natural peripheral sight, and its acuity closely matches the 100um pixel pitch of the implant. We present a progress toward 20um pixels based on honeycomb configuration of the stimulating arrays with return electrodes elevated on vertical walls, designed to leverage retinal migration for decoupling the stimulation threshold from pixel size.

The efficacy of photoimmunotherapy can be evaluated more accurately with an orthotopic mouse model than with a subcutaneous one. A pleural dissemination model can be used for the evaluation of treatment methods for intrathoracic diseases such as lung cancer or malignant pleural mesothelioma. Near-infrared photoimmunotherapy (NIR-PIT) is a recently developed cancer treatment strategy that combines the specificity of tumor-targeting antibodies with toxicity caused by a photoabsorber (IR700Dye) after exposure to NIR light. The efficacy of NIR-PIT has been reported using various antibodies; however, only a few reports have shown the therapeutic effect of this strategy in an orthotopic model. In the present study, we demonstrate an example of efficacy evaluation of the pleural disseminated lung cancer model, which was treated using NIR-PIT.

International audience; Photoinduced thermal polymerization upon Near-InfraRed (NIR) light has been recently reported in the literature as an efficient tool for polymer synthesis. In these different studies, a component capable to convert a NIR light into heat (called hereafter heater) was used in combination with a thermal initiator, promoting the Free-Radical Polymerization (FRP) of acrylate monomer. In this work, a completely different approach was developed since polymeric materials containing a very low amount of a stimuli-responsive compound were prepared by using a benchmark UV photoinitiator. As the stimuli-responsive compound, an

Climatic gradients frequently predict large-scale ecogeographical patterns in animal coloration, but the underlying causes are often difficult to disentangle. We examined ecogeographical patterns of reflectance among 343 European butterfly species and isolated the role of selection for thermal benefits by comparing animal-visible and near-infrared (NIR) wavebands. NIR light accounts for ~50% of solar energy but cannot be seen by animals so functions primarily in thermal control. We found that reflectance of both dorsal and ventral surfaces shows thermally adaptive correlations with climatic factors including temperature and precipitation. This adaptive variation was more prominent in NIR than animal-visible wavebands and for body regions (thorax-abdomen and basal wings) that are most important for thermoregulation. Thermal environments also predicted the reflectance difference between dorsal and ventral surfaces, which may be due to modulation between requirements for heating and cooling. These results highlight the importance of climatic gradients in shaping the reflectance properties of butterflies at a continent-wide scale.

Intelligent responsive microcarriers have emerged as a promising class of biomaterials for therapeutic delivery and tissue regeneration, since they can respond to external stimuli and release the loaded drugs in an active manner. Among various available stimuli, near‐infrared (NIR) light is particularly attractive because it can penetrate biotic tissues with sufficient intensity and minimal damage. In this work, a kind of photoresponsive delivery microcarriers (PDMs) is developed using microfluidics. The microcarriers consist of NIR‐absorbing graphene oxide, thermosensitive poly(N‐isopropylacrylamide), and biocompatible gelatin methacrylate. Under NIR light, the PDMs exhibit an evident volume shrinkage and effectively trigger the drug release. After the NIR light is switched off, the shrunken microcarriers return to their original size. This reversible process can be stably repeated for many cycles. An in vitro experiment demonstrates that the NIR‐radiated PDMs can actively release vascular endothelial growth factors and improve the tube formation of human umbilical vein endothelial cells. The results from the in vivo experiment also show an obvious photothermal effect and superior therapeutic efficacy of these PDMs in a rat model of tissue defects. These features make the PDMs an excellent drug delivery system and represent a great potential for clinical applications in tissue repair., Photoresponsive delivery microcarriers are developed using microfluidics, which consist of graphene oxide, poly(N‐isopropylacrylamide), and gelatin methacrylate. These microcarriers can actively respond to near‐infrared light and release the encapsulated drugs according to the irradiation frequency. After being implanted into a rat model of abdominal wall defects, they also exhibit potential value in tissue repair.

An on-demand drug delivery nanoplatform based on mesoporous silica (mSiO2) coated upconversion nanoparticles (UCNP@mSiO2) with a novel near-infrared (NIR) light-triggered hydrophobic-to-hydrophilic switch nanovalve was fabricated. The surface of UCNP@mSiO2 was first immobilized with hydrophobic 2-diazo-1,2-naphthoquinones (DNQ) guest molecules. After doxorubicin hydrochloride (DOX, a universal anticancer drug) was loaded into channels of mSiO2 shell, β-cyclodextrin (β-CD) host molecules with a hydrophobic cavity were added as gatekeepers to cap DNQ stalk molecules via hydrophobic affinity, which may play a role in the OFF state of the nanovalve to prevent the drug from being released. Upon 980 nm light irradiation, a NIR light-triggered hydrophobic-to-hydrophilic switch, that transformed the hydrophobic guest DNQ into hydrophilic guest 3-indenecarboxylic acid (ICA), took place so that the capped β-CD gatekeepers dissociated due to repulsion between β-CD host (hydrophobic) and ICA guest (hydrophilic), activating the ON state of the nanovalves to release drug. The in vitro studies prove that the nanoplatform enables on-demand drug release to efficiently kill HeLa cell upon NIR light regulation. The in vivo experiment results further confirm that the nanoplatform with such fabricated nanovalves is able to inhibit tumor growth in mice. The designed nanovalves based on the novel NIR light-triggered hydrophobic-to-hydrophilic switch strategy therefore may shed new light on future development of on-demand cancer therapy.

Early diagnosis and efficient therapy are very important for cancer management. Among the various intelligent delivery systems, near-infrared (NIR) light-triggered polymeric nanomicelles (PNMs) have emerged as a promising approach for imaging and photoactive delivery. This platform can be used for spatially and temporally controlled remote release of therapeutic payload molecules under NIR light irradiation. This review discusses the design and characteristics of PNMs as well as their recent application in imaging, drug delivery, and theranostics in photothermal and photodynamic therapy. The challenges and potential of PNMs in biomedical applications are also highlighted.

ZnIn2S4 is known to be a visible light-active photocatalyst. In this work, it is shown that by substituting part of the In atoms with vanadium, the visible light range of photocatalytic activity of such material can be extended, using the so-called in-gap band scheme that has been shown to enhance photovoltaic characteristics. Characterization of this material using several techniques, complemented by DFT calculations, will support this statement. While here only the degradation of aqueous HCOOH in well-aerated conditions is discussed, the same material may be used, with an adequate sacrificial reagent, for photocatalytic H2 generation., This research was funded by the Spanish Ministerio de Economía y Competitividad, grant number ENE2016-77798-C4 (project SEHTOP) and by Comunidad de Madrid, grant number S2013/MAE-2780 (project MADRID-PV). It is related also to COST Action 18234, supported by COST (European Cooperation in Science and Technology).

Theranostic nanoplatforms integrating simultaneously photodynamic therapy (PDT) and photothermal therapy (PTT) exhibit intrinsic advantages in tumor therapy due to distinct mechanisms of action. However, it is challenging to achieve PDT and PTT under single near-infrared (NIR) laser irradiation with a nanoplatform utilizing conventional organic photodynamic agent and inorganic photothermal agent owing to the difference in inherent excitation wavelengths. Particularly, the single NIR light (660 nm)-triggered PTT and PDT nanoplatform, constructed from chlorin e6 (Ce6) and copper sulfide (CuS) nanoparticles (NPs), has never been reported. Herein, we, for the first time, designed and established a dual-modal phototherapeutic nanoplatform that achieved both PTT and PDT under single NIR laser (660 nm) irradiation for Ce6 and CuS NPs with the strategy of core & ndash;shell structured CuS@Carbon inte-grated with Ce6. Introducing of carbon shell not only endows small CuS NPs with excellent tumor accu-mulation, but also significantly strengthens the photothermal performance of CuS NPs, realizing efficient photothermal performance under 660 nm laser irradiation. Moreover, Ce6 in carbon shell endowed the nanoplatform with photodynamic effect under 660 nm laser irradiation. The as-prepared Ce6/ CuS@Carbon nanoplatform thus achieved dual-modal phototherapy under single NIR laser irradiation, significantly inhibiting tumor growth with minimal adverse effects and superior biosafety. Refereed/Peer-reviewed

Multimodal imaging with NIR light is of great interest in medical research as its feasibility in combining with various techniques such as magnetic resonance imaging (MRI), X-ray computed tomography (CT), positron emission tomography (PET), single-photon emission computed tomography (SPECT), ultrasound (US), and photoacoustic (PA) imaging. This chapter gives an overview and backgrounds of diverse contrast agents for NIR mulimodal imaging associated with MRI, CT, PET/SPECT, and PA as a primal modality. It highlights potential applications in therapeutic practice using NIR light.

Latent fingerprint development plays an important role in forensic sciences. In the last two decades, various fluorescent nanomaterials have been used to develop latent fingerprints, of which rare earth ion–doped upconversion nanomaterials (UCNMs) are outstanding examples. The use of UCNMs is advantageous for several reasons, including high contrast due to the strong fluorescence signal and negligible background interference, high sensitivity owing to the tunable nanoparticle size, and high selectivity arising from the proper particle morphology with suitable absorbability. In most cases, NaYF4:Yb,Er UCNM-based development involves a single near-infrared (NIR)-to-visible (VIS) process, enabling the observation of fingerprints by detecting VIS light under NIR light excitation. Inspiringly, other infrequently used UCNMs, such as NaYbF4:Tm, can irradiate both NIR and VIS emissions under NIR excitation, making it possible to develop latent fingerprints in dual modes, namely, through both NIR-to-NIR and NIR-to-VIS process. In this work, we synthesized high-quality NaYbF4:Tm UCNMs as fluorescent markers for dual-mode development of latent fingerprints. We found that our NaYbF4:Tm UCNM–based method exhibited high contrast, high sensitivity, high selectivity, and extensive applicability in fingerprint development under both NIR-to-VIS and NIR-to-NIR modes. We expect that this work will open up a new avenue in the application of UCNMs to develop latent fingerprints under dual modes in forensic sciences.

In this study, Li-based blue- and green-emitting core@shell (C@S) upconversion nanophosphors (UCNPs) and NaGdF4-based red-emitting C@S UCNPs were synthesized, and IR-808 dyes were conjugated with the C@S UCNPs to enhance upconversion (UC) luminescence. The surface of the as-synthesized C@S UCNPs, which was originally capped with oleic acid, was modified with BF4&minus, to conjugate the IR-808 dye having a carboxyl functional group to the surface of the UCNPs. After the conjugation with IR-808 dyes, absorbance of the UCNPs was significantly increased. As a result, dye-sensitized blue (B)-, green (G)-, and red (R)-emitting UCNPs exhibited 87-fold, 10.8-fold, and 110-fold enhanced UC luminescence compared with B-, G-, and R-emitting Nd3+-doped C@S UCNPs under 800 nm near-infrared (NIR) light excitation, respectively. Consequently, dye-sensitized UCNPs exhibiting strong UC luminescence under 800 nm NIR light excitation have high applicability in a variety of biological applications.

Photodynamic therapy (PDT), a clinically approved cancer treatment strategy, features non-invasiveness, few side-effects, high spatial resolution, etc. The advancement of PDT has been significantly restricted by the penetration depth of the excitation light. Herein, an effective fluorogen, TBD, with aggregation-induced emission characteristics (AIEgen) and high reactive-oxygen-species (ROS) generation efficiency was reported and integrated with a near infrared (NIR) light excitable upconversion nanoparticle (UCNP) to construct NIR light excitable UCNP@TBD nanocomposites. The formed nanocomposite has excellent photostability, good biocompatibility, and efficient ROS generation under NIR light excitation via Forster resonance energy transfer (FRET), enabling NIR light excited PDT. Moreover, the proposed NIR light excited PDT can break the impasse between the penetration depth and excitation volume in conventional PDT, effectively improving the anticancer therapeutic outcome. In vitro cancer cell ablation and in vivo tumor growth inhibition validated that the proposed UCNP@TBD nanocomposite is a promising NIR light excitable PDT agent with great potential for future translational research.

Porphyrin‐based architectures have emerged as excellent candidates for artificial light‐harvesting antennae. Although tetrabenzoporphyrins (TBPs), the π‐extended “bigger brothers” of porphyrins, benefit from increased absorptivity in the near‐infrared (NIR), their utilization in light‐harvesting systems is still in its infancy. Within this work, we prepared two donor‐acceptor hetero dyads consisting of hexa‐peri‐hexabenzocoronenes (HBCs) to harvest high energetic near‐UV light, and a TBP core, which serves as visible to NIR light antenna and as subsequent energy sink of the conjugate. The HBCs are either attached to the meso‐position or via a maleimide‐bridge on the periphery of the macrocycle. Upon excitation of the HBC moieties, both dyads exhibit an efficient energy transfer to the TBP core. Furthermore, the TBP‐HBC dyads show superior light‐harvesting properties compared to the respective HBC‐porphyrin reference and the naturally occurring chlorophylls a/b.

Near-Infrared Spectroscopy (or NIRS) is an optical technique that uses near-infrared (NIR) light that can penetrate deep into the tissue. NIR light is transmitted to the head, non-invasively most often with the use of fibre optics. The collected, reflected NIR light from as deep as the cortex of the brain has been attenuated due to absorption of the oxygen dependent chromophore in the blood, the hemoglobin. NIRS most often measures the reflected NIR attenuation at a couple of wavelengths, to quantify the concentration of the oxygenated and deoxygenated hemoglobin ([HbO2], [HHb]) and provide information about the brain oxygen levels. Of particular interest are the changes in brain oxygenation due to neuronal activity as they can provide us with an indirect measurement of brain function. This can be measured with functional NIRS or fNIRS. For several years now we have been developing technology that extend fNIRS instrumentation by allowing measuring hundreds of NIR wavelengths instead of just two. The technique is called broadband near-infrared spectroscopy (or bNIRS). The bNIRS system measures changes in light attenuation, reflected back from the head, over 308 near-infrared (NIR) wavelengths (610nm to 918nm). This allow us to quantify the changes in brain tissue [HbO2], [HHb] and the concentration changes in the oxidation state of cerebral cytochrome-c-oxidase ([oxCCO]). In my talk I will discuss how we have been using bNIRS both in our preclinical and clinical investigations in neonatal hypoxic-ischemic injury to quantify brain injury severity and neurodevelopmental outcome.

Near-infrared imaging is an evolving technology that is increasingly being used in operating theatres. NIR technology includes fluorescent dyes and NIR-emitting lighted stents. There are a number of applications that utilise NIR light and include critical anatomy delineation of the biliary tree, urological tract (namely, the ureter and urethra) and critical vessel and nerve identification. The most common use of NIR light is to assess perfusion of gastrointestinal anastomoses, with the most widely reported outcomes relating to colorectal surgery. In oncological surgery, lymphatic mapping, primary tumour and metastatic deposit identification have all shown promising potential using non-specific fluorescent dyes.

Recently, video plethysmography (VPG) – a heart rate estimation technique using a video camera – has gained significant attention. Most studies of VPG have used a visible RGB camera; only a limited number of studies investigating near-infrared light (wavelength 750–2500 nm), which can be used even in a dark environment, have been performed. The purpose of this study was to investigate the differences between VPG data collected using visible light (VPG VIS ) or near-infrared light (VPG NIR ) from four facial areas (forehead, right cheek, left cheek, and nose). An experiment was conducted to obtain both VPG VIS and VPG NIR simultaneously by alternately irradiating the face with NIR and VIS lights. Experimental results showed that the root mean squared error of heart rate estimated using VPG NIR was 1 bpm higher than that of VPG VIS . However, contrary to our expectations, the power of the heartbeat-related component included in VPG NIR was not reduced despite the absorbance of hemoglobin in the NIR light range being 1/100 of that in the VIS light range. This result supports the hypothesis that a main factor in the generation of VPG waves was change in the optical properties caused by blood vessels compressing the subcutaneous tissue and the venous bed. Additionally, the accuracy of the heart rate estimation using VPG tended to be high when the nose was set as the ROI. This result was likely associated with the anatomical structure of the nose.

Orthogonal near-infrared light–controlled DNA nanodevices allow for biorecognition and treatment at right time and place., Despite the potential of nanodevices for intelligent drug delivery, it remains challenging to develop controllable therapeutic devices with high spatial-temporal selectivity. Here, we report a DNA nanodevice that can achieve tumor recognition and treatment with improved spatiotemporal precision under the regulation of orthogonal near-infrared (NIR) light. The nanodevice is built by combining an ultraviolet (UV) light–activatable aptamer module and a photosensitizer (PS) with up-conversion nanoparticle (UCNP) that enables the operation of the nanodevice with deep tissue–penetrable NIR light. The UCNPs can convert two distinct NIR excitations into orthogonal UV and green emissions for programmable photoactivation of the aptamer modules and PSs, respectively, allowing spatiotemporally controlled target recognition and photodynamic antitumor effect. Furthermore, when combined with immune checkpoint blockade therapy, the nanodevice results in regression of untreated distant tumors. This work provides a new approach for regulation of diagnostic and therapeutic activity at the right time and place.

Nanomaterials-based prodrug activation systems have been widely explored in cancer therapy, aiming at overcoming limited dosage formulation, systemic toxicity, and insufficient pharmacokinetic performance of parent drugs. For better delivery control, various stimuli systems, especially nanomaterials-based ones, have come to the forefront. Among them, near-infrared (NIR) light takes advantage of on-demand/site-specific regulation and non-invasiveness. In this review, we will address the developments of nanomaterials-based prodrug over the last decade, the activation mechanisms, and bioapplications under NIR light triggering. The advantages and limitations of NIR-triggered prodrug activation strategies and the perspectives of the next-generation prodrug nanomedicine will also be summarized. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Even though both farm and wild raw honeys are better than processed honey in terms of nutritional value and quality, wild honey is more expensive than farm honey due to its scarcity, nutrition, and quality. However, there is a challenge for consumer to differentiate both farm and wild raw honey due to the complexity of raw honey. Although near infrared (NIR) spectroscopy is promising to assist consumers to differentiate types of honeys, the financial barrier to have a NIR spectroscopy is needed to be addressed. Thus, this research aims to evaluate the performance of a low cost NIR light acquisition alternative in classifying stingless bee honeys using artificial neural network (ANN). First, 164 honey samples of two different types of raw honeys were prepared. Next, NIR light LEDs of five different wavelengths i.e. 850, 860, 870, 890, and 950 nm with light sensors were used to acquire the transmitted NIR absorbance from raw honey sample. ANN with different number of hidden neurons were used to analyze the data, and six datasets were used to investigate the best distance between NIR light source and light sensors. Results indicate that the acquired NIR light coupled with ANN by using eight hidden neurons and an average distance of 40 mm from light source to light sensor were able to produce the best result with the best true positive (TP) correct classification percentage accuracy and cross entropy (CE) value of 96.0% and 1.14, respectively.

Here, a novel triple-responsive graphene oxide hybrid supramolecular hydrogel based on the electrostatic self-assembly between graphene oxide and a quaternized polymer and the host-guest inclusion between α-cyclodextrins and poly(ethylene glycol) monomethyl ether (mPEG) was constructed. The quaternized polymer was synthesized by quaternization between pH-sensitive poly( N, N-dimethylaminoethyl methacrylate) and bromine end-capped poly(ethylene glycol) monomethyl ether. The supramolecular hydrogels prepared from the host-guest inclusion of poly(ethylene glycol) monomethyl ether and α-cyclodextrins would turn into a mobile sol phase when the temperature was increased above a certain temperature (Tgel-sol). Graphene oxide sheets not only acted as a core material to provide additional cross-linking but also absorbed NIR light and converted NIR light into heat to trigger the gel-sol transition. The constructed graphene oxide hybrid cyclodextrin-based supramolecular hydrogels could respond to NIR light, temperature, and pH, which could be beneficial for controlled release of cargoes and would hold great promise in the field of delivery systems.

Metal organic frameworks (MOFs) have attracted great interest as a smart drug delivery platform in the battle against cancer for their intriguing properties, such as high drug loading efficiency and microenvironment responsive degradation. Hence, the development of multifunctional MOFs integrating several theranostic elements is of crucial importance. In this work, we constructed a theranostic nanoplatform (DOX/Pd@ZIF-8) based on metal-organic frameworks encapsulating 2D Pd nanosheets and DOX using an all-in-one strategy, taking the advantages of the smart drug delivery function of MOFs and the excellent optical properties of Pd nanosheets. Polydopamine (PDA) was then introduced (DOX/Pd@ZIF-8@PDA) to improve the biocompatibility. DOX/Pd@ZIF-8@PDA exhibited excellent photothermal conversion effects and optoacoustic effects due to the strong NIR light absorption of Pd nanosheets. DOX was released in a pH-dependent manner and the release rates were accelerated in acidic solutions. However burst drug release in a relatively short period could be achieved upon 808 nm laser irradiation. Moreover, the potential of DOX/Pd@ZIF-8@PDA implemented as photoacoustic imaging contrast agents in vitro and in vivo was fully exploited and dual factor activated synergetic photo-chemo cancer therapy was successfully carried out.

The design of light-responsive peptide hydrogels with controllable drug release characteristics is still a challenge. Here, we fabricated a NIR light-responsive short peptide hydrogel by using a thermo-responsive short peptide hydrogel and PEGylated NbSe2 nanosheets, namely, the NbSe2–PEG@YD hydrogel. Under NIR light irradiation, the hydrogel began to collapse owing to the local heating, leading to the release of the cargos. The hydrogel exhibited recoverability and the release rate of the cargos could be accurately modulated by the NIR light irradiation according to the requirement. The excellent biocompatibility of this hydrogel ensured that it could be further developed as a drug carrier for clinical application.

Background Photobiomodulation (PBM) with red and near-infrared light (NIR) –also known as Low-Level Light Therapy–is a low risk, inexpensive treatment–based on non-retinal exposure–under study for several neuropsychiatric conditions. The aim of this paper is to discuss the proposed mechanism of action and to perform a systematic review of pre-clinical and clinical studies on PBM for major depressive disorder (MDD). Methods A search on MEDLINE and EMBASE databases was performed in July 2017. No time or language restrictions were used. Studies with a primary focus on MDD and presenting original data were included (n = 17). References on the mechanisms of action of PBM also included review articles and studies not focused on MDD. Results Red and NIR light penetrate the skull and modulate brain cortex; an indirect effect of red and NIR light, when delivered non-transcranially, is also postulated. The main proposed mechanism for PBM is the enhancement of mitochondrial metabolism after absorption of NIR energy by the cytochrome C oxidase; however, actions on other pathways relevant to MDD are also reported. Studies on animal models indicate a benefit from PBM that is comparable to antidepressant medications. Clinical studies also indicate a significant antidepressant effect and good tolerability. Limitations Clinical studies are heterogeneous for population and treatment parameters, and most lack an appropriate control. Conclusions Preliminary evidence supports the potential of non-retinal PBM as a novel treatment for MDD. Future studies should clarify the ideal stimulation parameters as well as the overall efficacy, effectiveness and safety profile of this treatment.

Stimuli-responsive systems, which can be used for temporally and spatially controllable therapeutic platforms, have been widely investigated in cancer therapy. Among a wide range of stimuli-responsive nanomaterials, transition metal dichalcogenides (TMDCs) have recently attracted great attention due to their large surface-to-volume ratio, atomic thickness, and other unique physicochemical properties. Thus, TMDCs are able to be responsive to various endogenous (e.g. acidic pH and overexpressed enzymes) or exogenous stimuli (e.g. light and magnetic). The majority of TMDC-based therapeutic platforms are triggered by near-infrared (NIR) light. However, due to the limited penetration of NIR light, novel strategies that are able to ablate deep-seated tumor tissues have emerged in recent years and have been applied to design multi-stimuli-responsive nano-systems. A comprehensive overview of the development of stimuli-responsive TMDC-based nanoplatforms for "smart" cancer therapy is presented to demonstrate a more intelligent and better controllable therapeutic strategy. Furthermore, the versatile properties of TMDCs and the typical responsive principles of certain stimuli-responsive platforms are discussed for a better understanding of selected examples in this review.

Quantitative detection of external stimuli, such as light, heat, and force, is an important challenge for sensing materials. Near-infrared (NIR) light is used in a variety of fields, such as biological, physical, medical, and engineering applications. Visualization and quantitative detection of invisible NIR are significant for its safe use. Here we fabricate a paper-based device coated with polypyrrole (PPy) and layered polydiacetylene (PDA). As PPy induces evolution of heat with irradiation of NIR, the effective conjugation length of the layered PDA is changed by the dynamic structure changed through the heat conduction. The visible color change from blue to red proceeds on the paper device. The red-color intensity has a relationship with the irradiation power of NIR. These facts suggest that the irradiation time and power of NIR are quantified by the color. Moreover, the results indicate that layered PDA can be applied to the quantification of external stimuli through conversion from the desired stimulus to the detectable one.

The application of optical technologies in treating pathologies and monitoring disease states requires the development of soft, minimal invasive and implantable devices to deliver light to tissues inside the body. Here, we present soft and degradable optical waveguides from poly(d,l-lactide) and derived copolymers fabricated by extrusion printing in the desired dimensions and shapes. The obtained optical waveguides propagate VIS to NIR light in air and in tissue at penetration depths of tens of centimeters. Besides, the printed waveguides have elastomeric properties at body temperature and show softness and flexibility in the range relevant for implantable devices in soft organs. Printed waveguides were able to guide light across 8 cm tissue and activate photocleavage chemical reactions in a photoresponsive hydrogel (in vitro). The simplicity and flexibility of the fiber processing method and the optical and mechanical performance of the obtained waveguides exemplify how rational study of medically approved biomaterials can lead to useful inks for printing cost-effective and flexible optical components for potential use in medical contexts.

With the goal of developing more accurate, efficient, non-invasive and fast diagnostic tools, the use of near-infrared (NIR) light in the range of the second and third biological windows (NIR-II: 1000–1350 nm, NIR-III: 1550–1870 nm) is growing remarkably as it provides the advantages of deeper penetration depth into biological tissues, better image contrast, reduced phototoxicity and photobleaching. Consequently, NIR-based bioimaging has become a quickly emerging field and manifold new NIR-emitting bioprobes have been reported. Classes of materials suggested as potential probes for NIR-to-NIR bioimaging (using NIR light for the excitation and emission) are quite diverse. These include rare-earth based nanoparticles, Group-IV nanostructures (single-walled carbon nanotubes, carbon nanoparticles and more recently Si- or Ge-based nanostructures) as well as Ag, In and Pb chalcogenide quantum dots. This review summarizes and discusses current trends, material merits, and latest developments in NIR-to-NIR bioimaging taking advantage of the region above 1000 nm (i.e. the second and third biological windows). Further consideration will be given to upcoming probe materials emitting in the NIR-I region (700–950 nm), thus do not possess emissions in these two windows, but have high expectations. Overall, the focus is placed on recent discussions concerning the optimal choice of excitation and emission wavelengths for deep-tissue high-resolution optical bioimaging and on fluorescent bioprobes that have successfully been implemented in in vitro and in vivo applications.

The development of light-controlled nitric oxide (NO)-releasing nanoplatforms that are capable of specifically targeting liver cancer cell lines and delivering an optimal amount of NO can significantly affect liver cancer therapy. In this study, a multifunctional nanoplatform {N-GQDs@Ru-NO@Gal} (1) for the near-infrared (NIR) light-responsive release of NO, consisting of a NO donor (Ru-NO) and a liver-targeting galactose derivative (Gal) covalently attached to N-doped graphene quantum dots (N-GQDs), was reported. Nanoplatform 1 preferentially targeted liver cancer cells over normal cells and instantly released NO as well as exhibited a prominent photothermal effect upon NIR irradiation at 808 nm, thereby leading to efficient anti-tumor efficacy. {N-GQDs@Ru-NO@Gal} with a small size (

Cancer cell-targeted imaging and efficient therapy are vital for tumor diagnosis and treatments. However, the development of multifunctional plasmonic nanoparticles with high-performance SERS-imaging and NIR light-triggered plasmonic photothermal therapy (PPTT) of cancer cells in both the first (NIR-I) and second (NIR-II) biological windows is still a big challenge. In the present work, gold nanostars which possess a broad NIR absorption band covering the NIR-I and NIR-II windows with good NIR SERS activity and photothermal effects were synthesized by a seed-mediated growth method, using gold chloride (HAuCl4), ascorbic acid (AA) and (1-hexadecyl) trimethylammonium chloride (CTAC) as growth solutions. The gold nanostars were further designed to be multifunctional nanoagents by labeling Raman molecules and then conjugating arginine–glycine–aspartic acid (RGD), which can serve as cancer cell-targeted SERS-imaging tags and photothermal nanoagents in both the NIR-I and NIR-II windows. The investigation of in vitro SERS-mapping and PPTT of the A549 human lung adenocarcinoma cells indicates that the proposed multifunctional gold nanostars have great potential for a wide spectrum of light-mediated applications, such as optical imaging and image-guided phototherapy in both the NIR-I and NIR-II biological windows.

Near-infrared (NIR) light-induced photothermal agent-based stimuli-responsive materials have attracted great interest from researchers. However, the highly smart release with precise control by NIR light is not yet well established because of the lack or inadequacy of intelligent release systems, such as premature release of drug and/or photothermal agent. Herein, we put forward a novel and convenient strategy to synthesize cyanine dye-functionalized polymeric materials, where cyanine dye was schemed to attach to polymeric materials by copolymerization, endowing the polymeric materials with NIR light-responsive photothermal property and fluorescent nature for real-time imaging of endocytosis and intracellular trafficking of nanovehicles. Meanwhile, the chemotherapy drug DOX was introduced into the cyanine-containing polymeric materials via formation of dynamic covalent hydrazone bond to circumvent the blood circulation barrier. The nanovehicles displayed fine pH/NIR light-controlled drug release and excellent tumor intracellular drug transposition, which were ulteriorly combined with photo-triggered hyperthermia for enhanced antitumor effect. Therefore, this multipronged design of theranostic nanovehicles with endogenous and exogenous stimuli-responsiveness provides a novel strategy to attain highly smart drug delivery for precise cancer therapy.

Harvesting of near infrared (NIR) light in the abundant and environmentally friendly solar spectrum is particularly significant to enhance the utilization rate of the cleanest energy on earth. Appreciating the unique nonlinear optical properties of upconversion materials for converting low-energy incident light into high-energy radiation, they become the most promising candidates for fabricating NIR light-active photocatalytic systems by integrating with semiconductors. The present review summarizes recent NIR light-active photocatalytic systems based on a sequence of NaYF4-based, fluoride-based, oxide-based and Ln3+ ion-doped semiconductor-based photocatalysts for degradation of organic molecules. In addition, we provide an in-depth analysis of various photocatalytic mechanisms and enhancement effects for efficient photo-redox performance of different upconversion semiconductor photocatalysts. We envision that this review can inspire multidisciplinary research interest in rational design and fabrication of efficient full-spectrum active (UV-visible-NIR) photocatalytic systems and their wider applications in solar energy conversion.

Light‐based technique, including optical imaging and photoregulation, has become one of the most important tools for both fundamental research and clinical practice, such as cell signal sensing, cancer diagnosis, tissue engineering, drug delivery, visual regulation, neuromodulation, and disease treatment. In particular, low energy near‐infrared (NIR, 700–1700 nm) light possesses lower phototoxicity and higher tissue penetration depth in living systems as compared with ultraviolet/visible light, making it a promising tool for in vivo applications. Currently, the NIR light‐based imaging and photoregulation strategies have offered a possibility to real‐time sense and/or modulate specific cellular events in deep tissues with subcellular accuracy. Herein, the recent progress with respect to NIR light for monitoring and modulating the spatiotemporal dynamics of cell functions in living systems are summarized. In particular, the applications of NIR light‐based techniques in cancer theranostics, regenerative medicine, and neuroscience research are systematically introduced and discussed. In addition, the challenges and prospects for NIR light‐based cell sensing and regulating techniques are comprehensively discussed., NIR light‐based technique, including optical imaging and photoreglation, has become one of the most important tools for both fundamental research and clinical practice. Herein, the recent progress of NIR light‐based cell function sensing and modulation in cancer theranostics, regenerative medicine, and neuroscience research is summarized.

The low-usage of solar energy and the sluggish separation efficiency of the photogenerated electrons/holes pairs are the obstacles in the practical application of photocatalysts. The integration of upconversion and Z-scheme heterojunction is expected to break the barriers to achieve the efficient charge separation and broaden near-infrared light absorption. Herein, an effective indirect Z scheme AgInS2/In2S3 heterostructure with carbon quantum dots (CQDs, as the electron conduction medium) and Lu3NbO7:Yb, Ho (as upconversion function) has been successfully synthesized. Consequently, the Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure exhibited superior photocatalytic activities for Cr(VI) reduction and H2O2 production, reducing 99.9% of Cr(VI)(20 ppm, 15 min) and 78.5% of Cr(VI) (40 ppm, 30 min) with visible light irradiation as well as 94.0% of Cr(VI) (20 ppm, 39 min) under NIR light irradiation. Simultaneously, the heterostructure could generate 902.9 μM H2O2 for 5 h under visible light irradiation. The intensive photocatalytic properties could primarily be attributed to the boosted light absorption capacity, the improved solar-to-energy conversion by the remarkable upconversion capacity of Lu3NbO7: Yb, Ho/CQDs and the faster charge transfer through a Z-schematic pathway. This work is anticipated to open a novel “window” for designing the efficient photocatalysts by coupling of Lu3NbO7: Yb, Ho and CQDs.

Artificial nanoreactors that can facilitate catalysis in living systems on-demand with the aid of a remotely operable and biocompatible energy source are needed to leverage the chemical diversity and expediency of advanced chemical synthesis in biology and medicine. Here, we designed and synthesized plasmonically integrated nanoreactors (PINERs) with highly tunable structure and NIR-light-induced synergistic function for efficiently promoting unnatural catalytic reactions inside living cells. We devised a synthetic approach toward PINERs by investigating the crucial role of metal-tannin coordination polymer nanofilm—the pH-induced decomplexation-mediated phase-transition process—for growing arrays of Au-nanospheroid-units, constructing a plasmonic corona around the proximal and reactant-accessible silica-compartmentalized catalytic nanospace. Owing to the extensive plasmonic coupling effect, PINERs show strong and tunable optical absorption in the visible to NIR range, ultrabright plasmonic light scatteri...

The BiOBr:Yb3+,Er3+/g-C3N4 (BYE/CN) p-n junction photocatalysts were successfully fabricated by a stepwise method. Experimental results show that Er3+/Yb3+ were successfully doped into BiOBr lattice. As-obtained BYE/CN exhibited strong NIR light absorption and upconversion emission from NIR to UV–visible due to the upconversion transition of Er3+. The p-n junction was constructed due to the appropriate alignment band structure of BYE and g-C3N4, which distinctly suppresses the recombination rate of electron-hole pairs. Compared with pure BYE and CN, as-synthesized BYE/CN samples exhibit distinctly improved photoactivities under the irradiation of visible or NIR light, which can be attributed to the upconversion effect of Er3+ and the construction of p-n junction. This result may provides a promising system for efficient harvest of the NIR light, which will contribute to the utilization of solar energy in the future.

Photoplethysmography has been routinely used for health monitoring in the past decades. Even though in daily medical practice, photoplethysmograms (PPGs) are recorded at red and near infra-red light (rPPGs), during the last decade, PPGs obtained at green light (gPPGs) have been widely used in wearable devices, such as wristbands and smartwatches, thus providing highly usable and accessible daily health monitoring. It is well recognized that PPG signals obtained at NIR light contain sufficient information about a person's health; furthermore, they are well-studied and highly complex. By contrast, green light PPGs have not been sufficiently studied; thus, it is not clear whether the provided information is as valuable as that obtained by rPPGs, as green light photoplethysmography is formed at papillary dermis and higher skin levels. However, the gPPG signal is recognized to be more robust to motion artifacts compared with rPPGs. As rPPG dynamics has been recognized as chaotic, this study is aimed at investigating the properties of gPPGs and compare them with those of rPPGs to determine whether gPPG dynamics is chaotic as well. The motivation for this question was not only to investigate whether gPPGs can be used for the same range of applications as rPPGs but also to obtain insight into whether the complexity of rPPGs is solely due to processes in deeper layers of the tissue or it is influenced by the higher-skin layers processes that create gPPGs. The obtained results demonstrated that gPPGs, as well as rPPGs, are chaotic, which implies that processes in the upper layers create chaos in PPG data, whereas the contribution of arterial blood volume changes is not completely clear.

Rare-earth doped upconversion nanophosphors (UCNPs), which convert low energy near-infrared (NIR) photons into high energy photons such as ultraviolet, visible light and NIR light, have found various applications in optical bioimaging. In this review article, we summarize recent advances in the synthesis and applications of UCNPs achieved by us and other groups in the past few years. The approaches for the synthesis of UCNPs are presented, with an emphasis on the role of green chemistry in the advancement of this field, followed by a focused overview on their latest applications in optical bioimaging from subcellular structures through cells to living animals. Challenges and opportunities for the use of UCNPs in biomedical diagnosis and therapy are discussed.

In the present work, we prepare and evaluate a cell-based microrobot for active drug delivery to tumors. The microrobots are fabricated using the engulfment activity of immune macrophages with drug-loaded magnetic liposomes (MNP-DLs) via phagocytosis. The synthesized MNP-DLs and the microrobots have high energy absorbance to NIR light with increased drug release rate after laser irradiation. The tumor killing ability of the prepared microrobots is validated on a colorectal cancer cell line. In addition, the active tumor targeting function by an external electromagnetic actuating (EMA) system and chemotaxis is verified. Experiment results show that a single microrobot can be manipulated by the EMA system to obtain the average velocity of approximately 11 μm/s, and the robots can cross the membranes mimicking the blood barrier to tumor chemo-attractants with the infiltration rate up to 74%. Consequently, this study proposes and analyzes an innovative aspect of the developed therapeutic cellular micro-platform for active tumor targeting and externally triggered drug delivery.

Driven by the growing demand for healthcare and point-of-care test applications, next-generation diagnostic tools of diseases require sensing platforms that enable rapid, quantitative readout of analytes with excellent specificity and sensitivity. Although label-free detection permits simplicity, flexibility and high specificity, it has usually poor throughput, limited sensitivity and requires professional instrumentation. Label-based detection using optical labels overcomes many of these drawbacks and has been demonstrated to be an effective alternative for improved sensing performances. The current research focus has been directed towards innovating high-performance optical labels for ultrasensitive biosensing and disease diagnostics in place of conventional optical labels. Surface-enhanced Raman scattering (SERS) labels have proven to be excellent labels for biosensing because of their merits in many aspects, such as flexibility, less interference from biological matrices, high photostability, easy multiplex encoding, etc. These fantastic features make SERS labels particularly suitable for ultrasensitive detection of disease biomarkers in body fluids and targeted imaging of diseased cells and tissues, respectively. In this Review, we introduce the design and deployment of SERS labels for ultrasensitive detection, and summarize recent research progress in the development of SERS label-based sensing platforms and their applications in disease biomarker detection, targeted cellular imaging and spectroscopic detection of tumor lesions. First, we will discuss the design principles and comprehensive considerations of SERS labels, and the on-demand integration of functionalities. Next, we introduce the design of SERS sensing platforms on basis of SERS labels for ultrasensitive and selective detection of diverse pathology-related biomarkers, including proteins, nucleic acids, small molecules and inorganic ions. In addition, through the rational incorporation of targeting ligands on SERS labels, novel SERS probes are created for targeting near-infrared (NIR) imaging and spectroscopic detection of tumor, taking advantages of large NIR light penetration depth, high brightness, stability, etc. Our and other research efforts have demonstrated the promising potential of SERS label-based sensing platforms for detection of diverse circulating biomarkers for non-invasive disease diagnostics and deep-tissue spectroscopic detection of tumor. It is believed that this review will motivate further exploration of clinical applications of SERS labels in near future.

We report a near-infrared (NIR) light-powered Janus mesoporous silica nanomotor (JMSNM) with macrophage cell membrane (MPCM) cloaking that can actively seek cancer cells and thermomechanically percolate cell membrane. Upon exposure to NIR light, a heat gradient across the Janus boundary of the JMSNMs is generated by the photothermal effect of the Au half-shells, resulting in a self-thermophoretic force that propels the JMSNMs. In biological medium, the MPCM camouflaging can not only prevent dissociative biological blocks from adhering to JMSNMs but also improve the seeking sensitivity of the nanomotors by specifically recognizing cancer cells. The biofriendly propulsion and recognition capability enable JMSNMs to achieve the active seeking and bind to the membrane of cancer cells. Subsequent illumination with NIR then triggers the photothermal effect of MPCM@JMSNMs to thermomechanically perforate the cytomembranes for guest molecular injection. This approach integrates the functions of active seeking, cytomembranes perforating, and thermomechanical therapy in nanomotors, which may pave the way to apply self-propelled motors in biomedical fields.