Near-infrared Sensitivity Research Articles

Flexible and Highly Photosensitive Electrolyte-Gated Organic Transistors with Ionogel/Silver Nanowire Membranes.

Flexible and low-voltage photosensors with high near-infrared (NIR) sensitivity are critical for realization of interacting humans with robots and environments by thermal imaging or night vision techniques. In this work, we for the first time develop an easy and cost-effective process to fabricate flexible and ultrathin electrolyte-gated organic phototransistors (EGOPTs) with high transparent nanocomposite membranes of high-conductivity silver nanowire (AgNW) networks and large-capacitance iontronic films. A high responsivity of 1.5 × 103 A·W1-, high sensitivity of 7.5 × 105, and 3 dB bandwidth of ∼100 Hz can be achieved at very low operational voltages. Experimental studies in temporal photoresponse characteristics reveal the device has a shorter photoresponse time at lower light intensity since strong interactions between photoexcited hole carriers and anions induce extra long-lived trap states. The devices, benefiting from fast and air-stable operations, provide the possibility of the organic photosensors for constructing cost-effective and smart optoelectronic systems in the future.

6-(2-Quinolinyl)-2,2′-bipyridine ruthenium complexes for near-infrared sensitization in dye-sensitized solar cells

In an effort to obtain a dye-sensitized solar cell (DSC) with a broader absorption band, four ruthenium (Ru) complexes based on 6-(2-quinolinyl)-2,2′-bipyridine ligands with a large π-conjugated system were synthesized. We investigated the relationship between the conversion efficiency of DSC and the structure of quinoline-based Ru complex as well as the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) potentials. As compared with black dye, all of these complexes showed red-shifted absorption edges. The results of electrochemical analyses and theoretical calculations indicated that the shift of the absorption bands comes from the electron-withdrawing or electron-delocalization effect of the quinoline ring of the ligands. In addition, the number and position of carboxyl groups significantly affected the distribution of HOMO and LUMO thereby shifting their potentials. Comparison of the performance of the DSCs using different complexes revealed that the electron injection efficiency was also significantly affected by the position of the carboxyl groups. In this study, the Ru complex with the ligand composed of both 4-carboxypyridine and 4-carboxyquinoline efficiently sensitized near-IR photons as well as visible photons.

Near infrared spectroscopy for body fat sensing in neonates: quantitative analysis by GAMOS simulations

BackgroundUnder-nutrition in neonates is closely linked to low body fat percentage. Undernourished neonates are exposed to immediate mortality as well as unwanted health impacts in their later life including obesity and hypertension. One potential low cost approach for obtaining direct measurements of body fat is near-infrared (NIR) interactance. The aims of this study were to model the effect of varying volume fractions of melanin and water in skin over NIR spectra, and to define sensitivity of NIR reflection on changes of thickness of subcutaneous fat. GAMOS simulations were used to develop two single fat layer models and four complete skin models over a range of skin colour (only for four skin models) and hydration within a spectrum of 800–1100 nm. The thickness of the subcutaneous fat was set from 1 to 15 mm in 1 mm intervals in each model.ResultsVarying volume fractions of water in skin resulted minimal changes of NIR intensity at ranges of wavelengths from 890 to 940 nm and from 1010 to 1100 nm. Variation of the melanin volume in skin meanwhile was found to strongly influence the NIR intensity and sensitivity. The NIR sensitivities and NIR intensity over thickness of fat decreased from the Caucasian skin to African skin throughout the range of wavelengths. For the relationship between the NIR reflection and the thickness of subcutaneous fat, logarithmic relationship was obtained.ConclusionsThe minimal changes of NIR intensity values at wavelengths within the ranges from 890 to 940 nm and from 1010 to 1100 nm to variation of volume fractions of water suggests that wavelengths within those two ranges are considered for use in measurement of body fat to solve the variation of hydration in neonates. The stronger influence of skin colour on NIR shows that the melanin effect needs to be corrected by an independent measurement or by a modeling approach. The logarithmic response obtained with higher sensitivity at the lower range of thickness of fat suggests that implementation of NIRS may be suited for detecting under-nutrition and monitoring nutritional interventions for malnutrition in neonates in resource-constrained communities.

“Gold nanoparticles composite-folic acid conjugated graphene oxide nanohybrids” for targeted chemo-thermal cancer ablation: In vitro screening and in vivo studies

Nano-graphene oxide (GO) nanometal composite (specifically nanogold and nanosilver) have shown to be a promising material for anticancer therapeutics. Owing to their high drug loading capacity, photothermal and synergizing effects, it is very important to exploit them for targeted chemo-thermal cancer therapeutics. In this work, gold nanoparticles (AuNPs) were selected as the composite metal, folic acid (FA) was taken as GO surface functionalization moiety for active tumor targeting of model anticancer drug Doxorubicin (Dox). AuNPs composite-folate conjugated graphene oxide (FA-GO@Au) nano-platforms were synthesized and characterized in detail. Near-infrared (NIR) sensitivity resulted in an aggravated release of both Dox and ionic gold from the nanohybrid surface. Simultaneous delivery of Dox and AuNPs in the cellular vicinity was further enhanced after localized NIR exposure which resulted in significantly improved cancer cell toxicity. Mechanistic evaluation revealed G0/G1 phase arrest due to increased DNA intercalation and provoked early apoptosis under NIR influence. Pharmacokinetics and organ distribution studies were carried out in healthy mice and rabbits to estimate the actual bio fate of these nanohybrids. In vivo studies showed substantial tumor regression in solid tumor model in Balb/c mice and NIR exposure induced photo-thermal effects further resulted in better tumor management. Study provides substantial evidences both at in vitro and in vivo level to support the fact that NIR induced local photo-thermal effects can solely be used as a tumor targeting tool. This NIR dependent nanohybrid approach presents a precise and flexible strategy for targeted chemotherapy and photo-thermal tumor ablation.

Multifunctional Photosensitizer Grafted on Polyethylene Glycol and Polyethylenimine Dual-Functionalized Nanographene Oxide for Cancer-Targeted Near-Infrared Imaging and Synergistic Phototherapy.

The integration of photodynamic therapy (PDT) with photothermal therapy (PTT) offers improved efficacy in cancer phototherapy. Herein, a PDT photosensitizer (IR-808) with cancer-targeting ability and near-infrared (NIR) sensitivity was chemically conjugated to both polyethylene glycol (PEG)- and branched polyethylenimine (BPEI)-functionalized nanographene oxide (NGO). Because the optimal laser wavelength (808 nm) of NGO for PTT is consistent with that of IR-808 for PDT, the IR-808-conjugated NGO sheets (NGO-808, 20-50 nm) generated both large amounts of reactive oxygen species (ROS) and local hyperthermia as a result of 808 nm laser irradiation. With PEG- and BPEI-modified NGO as the carrier, the tumor cellular uptake of NGO-808 exhibited higher efficacy than that of strongly hydrophobic free IR-808. Through evaluation with both human and mouse cancer cells, NGO-808 was demonstrated to provide significantly enhanced PDT and PTT effects compared to individual PDT using IR-808 or PTT using NGO. Furthermore, NGO-808 preferentially accumulated in cancer cells as mediated by organic-anion transporting polypeptides (OATPs) overexpressed in many cancer cells, providing the potential for highly specific cancer phototherapy. Using the targeting ability of NGO-808, in vivo NIR fluorescence imaging enabled tumors and their margins to be clearly visualized at 48 h after intravenous injection, providing a theranostic platform for imaging-guided cancer phototherapy. Remarkably, after a single injection of NGO-808 and 808 nm laser irradiation for 5 min, the tumors in two tumor xenograft models were ablated completely, and no tumor recurrence was observed. After treatment with NGO-808, no obvious toxicity was detected in comparison to control groups. Thus, high-performance cancer phototherapy with minimal side effects was afforded from synergistic PDT/PTT treatment and cancer-targeted accumulation of NGO-808.

Single-Photon Avalanche Diode with Enhanced NIR-Sensitivity for Automotive LIDAR Systems.

A single-photon avalanche diode (SPAD) with enhanced near-infrared (NIR) sensitivity has been developed, based on 0.18 μm CMOS technology, for use in future automotive light detection and ranging (LIDAR) systems. The newly proposed SPAD operating in Geiger mode achieves a high NIR photon detection efficiency (PDE) without compromising the fill factor (FF) and a low breakdown voltage of approximately 20.5 V. These properties are obtained by employing two custom layers that are designed to provide a full-depletion layer with a high electric field profile. Experimental evaluation of the proposed SPAD reveals an FF of 33.1% and a PDE of 19.4% at 870 nm, which is the laser wavelength of our LIDAR system. The dark count rate (DCR) measurements shows that DCR levels of the proposed SPAD have a small effect on the ranging performance, even if the worst DCR (12.7 kcps) SPAD among the test samples is used. Furthermore, with an eye toward vehicle installations, the DCR is measured over a wide temperature range of 25–132 °C. The ranging experiment demonstrates that target distances are successfully measured in the distance range of 50–180 cm.

Near-Infrared Light Activation of Proteins Inside Living Cells Enabled by Carbon Nanotube-Mediated Intracellular Delivery.

Light-responsive proteins have been delivered into the cells for controlling intracellular events with high spatial and temporal resolution. However, the choice of wavelength is limited to the UV and visible range; activation of proteins inside the cells using near-infrared (NIR) light, which has better tissue penetration and biocompatibility, remains elusive. Here, we report the development of a single-walled carbon nanotube (SWCNT)-based bifunctional system that enables protein intracellular delivery, followed by NIR activation of the delivered proteins inside the cells. Proteins of interest are conjugated onto SWCNTs via a streptavidin-desthiobiotin (SA-DTB) linkage, where the protein activity is blocked. SWCNTs serve as both a nanocarrier for carrying proteins into the cells and subsequently a NIR sensitizer to photothermally cleave the linkage and release the proteins. The released proteins become active and exert their functions inside the cells. We demonstrated this strategy by intracellular delivery and NIR-triggered nuclear translocation of enhanced green fluorescent protein, and by intracellular delivery and NIR-activation of a therapeutic protein, saporin, in living cells. Furthermore, we showed that proteins conjugated onto SWCNTs via the SA-DTB linkage could be delivered to the tumors, and optically released and activated by using NIR light in living mice.

Organic near-infrared upconversion devices: Design principles and operation mechanisms

Optical upconversion devices up-converting near-infrared (NIR) light to visible light have attracted a great deal of research interest in the past decades. Among these devices, organic upconversion devices have been presented as an alternative strategy for simplifying the fabrication process and reducing the cost. In recent years, along with the development of organic electronics, several types of organic NIR upconversion devices have been reported. However, there have been very few systematic studies of the design principles and operation mechanisms of organic NIR upconversion devices. In order to illustrate the structural design principles and operation mechanisms, organic upconversion devices based on donor/acceptor planar heterojunction (PHJ) as NIR sensitizer and inverted OLED structure as emitter are fabricated and studied. Significantly, two types of photo-generated electron and hole based organic upconversion devices are realized by ingeniously exchanging the position of the PHJ and the inverted OLED in the devices, respectively. The light emission in the former results from the recombination of photo-generated electrons with the injected holes from the anode, while that of the later from the recombination of photo-generated holes with the injected electrons from the cathode. Both types of the upconversion devices demonstrated great potentials for future pixel-less NIR imaging applications.

Sensitivity of Interferometric Cross-Polarization Microscopy for Nanoparticle Detection in the Near-Infrared

We address the sensitivity of Interferometric Cross-Polarization Microscopy by comparing scattering and absorption by spherical 10 nm nanoparticles through a combination of modeling and experiment. We show that orthogonality of light in the two polarization branches of Cross-Polarization Microscopy ensures that only light that has interacted with a nanoparticle is interferometrically enhanced. As a result background-free shot noise-limited detection is achieved for sub-μW optical powers at the sample. Our modeling in particular shows that in the near-infrared regime, above the plasmon resonance frequency of spherical nanoparticles, the cross-polarization approach is several orders of magnitude more sensitive than conventional extinction based detection. This enhanced near-infrared sensitivity for spherical nanoparticles is promising for applications requiring low absorption and low power imaging of nanoparticles in cells.

Near-infrared squaraine sensitizers bearing benzo[c,d]indolenine as an acceptor moiety

Near-infrared absorbing unsymmetrical squaraine dyes bearing benzo[c,d]indolenine as an acceptor moiety have been synthesized and their light-absorbing properties and performance as sensitizers for dye-sensitized solar cells were studied. A molecular-orbital calculation indicated that the electron distribution moved from the cyclobutene skeleton to the benzo[c,d]indolenine components with a carboxy group through photoexcitation. The squaraines exhibited prominent absorption properties in the range 600–900 nm, whereas these dyes show a tendency to aggregate in solution as well as on a titania due to an effect of the π-extended benzo[c,d]indolenine. Their absorption and electrochemical properties revealed that these dyes have deep lowest unoccupied molecular orbital levels which are close to the potential of the titania conduction band. Dye-sensitized solar cell using the present dyes achieved a spectral response in the range from 940 nm to 400 nm. These results indicated that benzo[c,d]indolenine with a carboxy group can be applied to the components for near-infrared-absorbing sensitizers in photovoltaic cells.

Characterization of Conventional One-Step Sodium Thiosulfate Facilitated Gold Nanoparticle Synthesis.

Gold-gold sulfide nanoparticles are of interest for drug delivery, biomedical imaging, and photothermal therapy applications due to a facile synthesis method resulting in small particles with high near-infrared (NIR) absorption efficiency. Previous studies suggest that the NIR sensitivity of these nanoparticles was due to hexagonally shaped metal-coated dielectric nanoparticles that consist of a gold sulfide core and gold shell. Here, we illustrate that the conventional synthesis procedure results in the formation of polydisperse samples of icosahedral gold particles, gold nanoplates, and small gold spheres. Importantly, through compositional analysis, via UV/vis absorption spectrophotometry, transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDS), we show that all of the nanoparticles exhibit identical face center cubic (FCC) gold crystalline structures, thus suggesting that sulfide is not present in the final fabricated nanoparticles. We show that icosahedrally shaped nanoparticles result in a blue-shifted absorbance, with a peak in the visible range. Alternatively, the nanoplate nanoparticles result in the characteristic NIR absorbance peak. Thus, we report that the NIR-contributing species in conventional gold-gold sulfide formulations are nanoplates that are comprised entirely of gold. Furthermore, polydisperse gold nanoparticle samples produced by the traditional one-step reduction of HAuCl4 by sodium thiosulfate show increased in vitro toxicity, compared to isolated and more homogeneous constituent samples. This result exemplifies the importance of developing monodisperse nanoparticle formulations that are well characterized in order to expedite the development of clinically beneficial nanomaterials.

ChemInform Abstract: Recent Progress in Organic Sensitizers for Dye‐Sensitized Solar Cells

AbstractReview: [110 refs.

Near-Infrared Asymmetrical Squaraine Sensitizers for Highly Efficient Dye Sensitized Solar Cells: The Effect of π-Bridges and Anchoring Groups on Solar Cell Performance

Conventional squaraine dyes exhibit an intense absorption band in the red region of the solar spectrum and with appropriate design can also have high energy absorption as well, making them interesting building blocks toward achieving panchromatic dyes for dye sensitized solar cell (DSSC) applications. In this report, eight squaraine dyes with thiophene, 4-hexyl-4H-dithieno[3,2-b:2′,3′-d]pyrrole, dithieno[3,2-b:2′,3′-d]thiophene, and 4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene (DTS) π-bridges with cyanoacetic acid (CA) and cyanophosphonic acid (PA) acceptor/anchoring groups are synthesized to extend the squaraine absorption into the 450–550 nm region and to provide different spatial arrangements of solubilizing groups. Squaraines with CA anchoring groups have higher power conversion efficiencies compared to their PA analogs, with the highest being 8.9% for the DTS-based dye, which is among the highest reported in the literature for squaraine dyes. This is due to high short circuit currents (JSC) and increased open circuit voltages (VOC). Dyes with PA anchoring groups exhibited lower JSC resulting from decreased charge injection efficiency, as determined by femtosecond transient absorption spectroscopy. This study suggests that out-of-plane bulky substituents may increase DSSC performance not only by increasing JSC through decreased aggregation but also by increasing VOC through decreased TiO2/electrolyte recombination.

Shape-switching microrobots for medical applications: the influence of shape in drug delivery and locomotion.

The effect of dynamic shape switching of hydrogel bilayers on the performance of self-folding microrobots is investigated for navigation in body orifices and drug release on demand. Tubular microrobots are fabricated by coupling a thermoresponsive hydrogel nanocomposite with a poly(ethylene glycol)diacrylate (PEGDA) layer, to achieve spontaneous and reversible folding from a planar rectangular structure. Graphene oxide (GO) or silica-coated superparamagnetic iron oxide nanoparticles are dispersed in the thermoresponsive hydrogel matrix to provide near-infrared (NIR) light sensitivity or magnetic actuation, respectively. The NIR light-responsive microstructures are fabricated for triggered drug delivery while magnetic nanocomposite-based microrobots are used to analyze the role of shape in locomotion. Experimental analysis and computational simulations of tubular structures show that drug release and motility can be optimized through controlled shape change. These concepts are finally applied to helical microrobots to show a possible way to achieve autonomous behavior.

One-Photon Near-Infrared Sensitization of Well-Defined Yb(III) Surface Complexes for NIR-to-NIR Single Nanoparticle Imaging

Silica nanoparticles of 12 nm diameter were surface-doped with ca. 350 (TTF-dppz)Yb(III) surface species, containing bis(propylthio)tetrathiafulvenyl[i]dipyrido-[3,2-a:2′,3-c]phenazine (TTF-dppz) as an antenna ligand through a surface organometallic chemistry approach. These nanoparticles absorb and emit in the NIR (λabs = 750 nm, λem = 983 and 1050 nm) with a lifetime (τ1) of 2.8 μs, similarly to the corresponding Yb(III) molecular complex (λabs = 750 nm, λem = 975, 986, 1009, and 1020 nm with τ1 = 6.93 μs). The silica materials were fully characterized using combined spectroscopic techniques (IR, NMR, UV–vis, luminescence and lifetime), molecular models and isostructural diamagnetic yttrium-containing materials for easier characterization by NMR spectroscopy. Having established the surface structures and photophysical properties of these nanoparticles, we transposed this methodology to larger silica particles with a diameter of ca. 100 nm. These larger nanoparticles have similar photophysical properties and contain ca. 30 000 chromophores, making possible one-photon NIR-to-NIR emission optical microscopy imaging of single nanoparticles.

Monitoring of riparian vegetation response to flood disturbances using terrestrial photography

Abstract. Flood disturbance is one of the major factors impacting riparian vegetation on river floodplains. In this study we use a high-resolution ground-based camera system with near-infrared sensitivity to quantify the immediate response of riparian vegetation in an Alpine, gravel bed, braided river to flood disturbance with the use of vegetation indices. Five large floods with return periods between 1.4 and 20.1 years in the period 2008–2011 in the Maggia River were analysed to evaluate patterns of vegetation response in three distinct floodplain units (main bar, secondary bar, transitional zone) and to compare the sensitivity of seven broadband vegetation indices. The results show both a negative (damage) and positive (enhancement) response of vegetation within 1 week following the floods, with a selective impact determined by pre-flood vegetation vigour, geomorphological setting and intensity of the flood forcing. The spatial distribution of vegetation damage provides a coherent picture of floodplain response in the three floodplain units. The vegetation indices tested in a riverine environment with highly variable surface wetness, high gravel reflectance, and extensive water–soil–vegetation contact zones differ in the direction of predicted change and its spatial distribution in the range 0.7–35.8%. We conclude that vegetation response to flood disturbance may be effectively monitored by terrestrial photography with near-infrared sensitivity, with potential for long-term assessment in river management and restoration projects.

Theoretical design of highly efficient porphyrazine solar cells

Density functional theory and time-dependent density functional theory methodologies have been applied to design porphyrazine (tetraazaporphyrin) sensitizers. This was done by replacing the porphyrin macrocycle cavity with a porphyrazine macrocycle cavity and increasing the number of p-carboxyphenyl moieties at the macrocycle periphery so that the performances of the suggested cells could be expected to exceed the efficiency of the reference YD2-o-C8 porphyrin sensitizer with Ti38O76, (TiO2)60, SiC, ZrO2, and GaP semiconductor electrodes. Macrocycle replacement assists in promoting the efficiency in the red shoulder of the spectrum more effectively than increasing the number of anchoring groups. The expected effects of the former structural modifications on cell performances are confirmed in terms of natural transition orbitals, energy gaps, semiconductor valence bands and conduction band edges, density of states, UV–visible absorption, and lifetimes of the excited states ΦLHE, Φinject., and ΔGregen. The structural modifications resulted in charge-separated states, unidirectional charge transfer, narrower band gaps, increase of density of states nearby Fermi levels, delocalization of the negative charges near the anchoring groups, efficient light harvesting and electron injection, suppressing macrocycle aggregation, active dye regeneration, and inhibited dye recombination. Co-sensitizers are suggested for near-infrared sensitization.

A Near-Infrared Dithieno[2,3-a:3′,2′-c]phenazine-Based Organic Co-Sensitizer for Highly Efficient and Stable Quasi-Solid-State Dye-Sensitized Solar Cells

A novel near-infrared (NIR) organic sensitizer FNE53 with a strong electron-withdrawing unit, dithieno[2,3-a:3',2'-c]phenazine, has been designed and synthesized for quasi-solid-state dye-sensitized solar cells (DSSCs). By simply fusing the two thiophene rings on quinoxaline unit in sensitizer FNE48, the intramolecular charge transfer (ICT) band bathochromically shifts from 542 nm for FNE48 to 629 nm for FNE53 in toluene solution. The absorption spectrum of sensitizer FNE53 covers the whole visible region and extends to the NIR region, which exhibits complementary absorption profile to another organic dye FNE46 based on quinoxaline. When FNE46 and FNE53 are used as cosensitizers for metal-free cocktail-type quasi-solid-state DSSCs, sensitizer FNE53 not only extends the photoresponse range but also suppresses the intermolecular interactions among the dye molecules. Therefore, the cocktail-type quasi-solid-state DSSC displays much higher IPCE value compared with that for the DSSC sensitizer based on FNE53 and a broader IPCE response in comparison to that for the DSSC sensitizers based on FNE46, respectively. After the molar ratio between the two cocktail dyes is optimized, the highest energy conversion efficiency of 8.04% is achieved in a metal-free quasi-solid-state DSSC cosensitized with FNE46 and FNE53, which exhibits good long-term stability after continuous light soaking for 1000 h.

Near-IR organic sensitizers containing squaraine and phenothiazine units for dye-sensitized solar cells

Unsymmetrical squaraine near-infrared (NIR) sensitizers with variable π-bridge units, based on the donor-π-squaraine core-acceptor structural motif, were synthesized and used as sensitizers for dye-sensitized solar cells. The phenothiazine as a donor group was linked to a squaraine core unit using various thiophene derivatives. Among them, three squaraine-based sensitizers have a carboxylic acid group as an electron-accepting group directly attached to the squaraine component, while one of four squaraine-based sensitizers has a cyanoacrylic acid as a more strongly electron-accepting group directly attached to the squaraine component. The sensitizers exhibited intense absorption in the NIR region and strong luminescence. The LUMO levels of the present squaraine-based sensitizers were slightly more negative than the conduction band edge of TiO2 photoanode. As a result, a solar cell based on the squaraine-based sensitizer containing a thiophene unit as a π-bridge unit and a carboxylic acid group as an electron-accepting group exhibited better photovoltaic performance with a JSC of 6.0 mA cm−2, a VOC of 448 mV, and an FF of 0.73, corresponding to an overall conversion efficiency η of 2.0%.

Photoluminescent graphene nanoparticles for cancer phototherapy and imaging.

Graphene-based nanomaterials are of great interest in a wide range of applications in electronics, the environment, and energy as well as in biomedical and bioengineering. Their unique properties make them generally applicable as prognostic, diagnostic, and therapeutic agents in cancer. In this work, we focused on photodynamic and photothermal therapeutic properties of our previously synthesized carboxylated photoluminescent graphene nanodots (cGdots). The cGdots are ∼5 nm in diameter and excited at 655 nm. Our findings reveal that, upon laser irradiation by near-infrared (wavelength 670 nm) sensitizer, electrons of the cGdots starts to vibrate and form electron clouds, thereby generating sufficient heat (>50 °C) to kill the cancer cells by thermal ablation. The generation of singlet oxygen also occurs due to irradiation, thus acting similarly to pheophorbide-A, a well-known photodynamic therapeutic agent. The cGdots kills MDA-MB231 cancer cells (more than 70%) through both photodynamic and photothermal effects. The cGdots were equally effective in the in vivo model of MDA-MB231 xenografted tumor-bearing mice also as observed for 21 days. The cGdot was intravenously injected, and the tumor was irradiated by laser, resulting in final volume of tumor was ∼70% smaller than that of saline-treated tumor. It indicates that the growth rate of cGdot-treated tumor was slower compared to saline-treated tumor. The synthesized cGdots could enable visualization of tumor tissue in mice, thereby illustrating their use as optical imaging agents for detecting cancer noninvasively in deep tissue/organ. Collectively, our findings reveal that multimodal cGdots can be used for phototherapy, through photothermal or photodynamic effects, and for noninvasive optical imaging of deep tissues and tumors simultaneously.