Ag2S Quantum Dots Research Articles

DNA-Engineered Degradable Invisibility Cloaking for Tumor-Targeting Nanoparticles.

Nanoparticle (NP) delivery systems have been actively exploited for cancer therapy and vaccine development. Nevertheless, the major obstacle to targeted delivery lies in the substantial liver sequestration of NPs. Here we report a DNA-engineered approach to circumvent liver phagocytosis for enhanced tumor-targeted delivery of nanoagents in vivo. We find that a monolayer of DNA molecules on the NP can preferentially adsorb a dysopsonin protein in the serum to induce functionally invisibility to livers; whereas the tumor-specific uptake is triggered by the subsequent degradation of the DNA shell in vivo. The degradation rate of DNA shells is readily tunable by the length of coated DNA molecules. This DNA-engineered invisibility cloaking (DEIC) is potentially generic as manifested in both Ag2S quantum dot- and nanoliposome-based tumor-targeted delivery in mice. Near-infrared-II imaging reveals a high tumor-to-liver ratio of up to ∼5.1, approximately 18-fold higher than those with conventional nanomaterials. This approach may provide a universal strategy for high-efficiency targeted delivery of theranostic agents in vivo.

Biomimetic Tumor Cell Membrane‐Encapsulated Nanoparticles Combine NIR‐II Photothermal Therapy and Chemotherapy for Enhanced Immunotherapy in Triple‐Negative Breast Cancer

AbstractTo advance the understanding and potential treatment strategies for triple‐negative breast cancer (TNBC), particularly focusing on its high metastatic propensity and uncertain molecular targets, a biomimetic tumor cell membrane‐encapsulated nanodelivery system is developed for enhanced immunotherapy. This system is assembled with the second near‐infrared (NIR‐II) photothermal agent, chemotherapeutic drug, and programmed death‐ligand 1 (PD‐L1) inhibitors camouflaged by TNBC cell membranes. An NIR‐II Ag2S quantum dots (QDs) is introduced for not only realizing pronounced imaging‐guided photothermal therapy (PTT), but also co‐activating immunogenic cell death (ICD) with chemotherapy. Homologous targeting and camouflage properties endowed the nanodelivery system with excellent biocompatibility and efficient delivery ability to the tumor site, demonstrating excellent synergistic therapeutic efficacy. The release of damage‐associated molecular patterns (DAMP) marked the induction of ICD, crucial for reshaping the immune microenvironment. Further integration of α‐PD‐L1 achieved a 56.5% immune checkpoint inhibition rate, synergistically amplifying immune response to ultimately activate key cytokines, thereby achieving pronounced anti‐tumor immunotherapy effects. Notably, this approach realized a considerable reduction of metastatic nodules by 51.2% in the TNBC lung metastasis model. The proposed nanodelivery system extended tumor remission and effectively reduced lung metastasis, paving the way for a reliable and promising approach in TNBC immunotherapy.

Polyvalent Aptamer-Functionalized NIR-II Quantum Dots for Targeted Theranostics in High PD-L1-Expressing Tumors.

Ag2S quantum dots (QDs) show superior optical properties in the NIR-II region and display significant clinical potential with favorable biocompatibility. However, inherent defects of low targeting and poor solubility necessitate practical modification methods to achieve the theranostics of Ag2S QDs. Herein, we used rolling circle amplification (RCA) techniques to obtain long single-stranded DNA containing the PD-L1 aptamer and C-rich DNA palindromic sequence. The C-rich DNA palindromic sequences can specifically chelate Ag2+ and thus serve as a template to result in biomimetic mineralization and formation of pApt-Ag2S QDs. These QDs enable specific targeting and illuminate hot tumors with high PD-L1 expression effectively, serving as excellent molecular targeted probes. In addition, due to the high NIR-II absorption of Ag2S QDs, pApt-Ag2S QDs exhibit remarkable photothermal properties. And besides, polyvalent PD-L1 aptamers can recognize PD-L1 protein and effectively block the inhibitory signal of PD-L1 on T cells, enabling efficient theranostics through the synergistic effect of photothermal therapy and immune checkpoint blocking therapy. Summary, we enhance the biological stability and antibleaching ability of Ag2S QDs using long single-stranded DNA as a template, thereby establishing a theranostic platform that specifically targets PD-L1 high-expressing inflamed tumors and demonstrates excellent performance both in vitro and in vivo.

In-situ synthesis of CdS and Ag2S quantum dots in poly(diallyldimethylammonium chloride) gels

In this study, we proposed a hybridization method for polymer and quantum dots (QDs) by directly forming QDs in polymer gel; this method was completely different from conventional methods such as mixing and encapsulation. QDs were fabricated by reacting metal ions in solution with sulfide ions adsorbed in a gel made from poly(diallyldimethylammonium chloride) (PDADMAC), a cationic polymer. CdS and Ag2S QDs were successfully fabricated in PDADMAC gel for in situ synthesis, and visible light (534 nm) and NIR (1070 nm) emissions were observed in PDADMAC gel containing CdS and Ag2S QDs, respectively. We also discussed the formation mechanism of QDs in the gel considering the mesh size of polymer networks in PDADMAC gel.

NIR-responsive photoelectrochemical sensing platform for the simultaneous determination of tetrodotoxin and okadaic acid in Nassariidae

Simultaneous detection of tetrodotoxin (TTX) and okadaic acid (OA) is important for seafood safety. In this work, a novel paper electrode-based near-infrared (NIR) light-responsive photoelectrochemical (PEC) immunosensor was constructed using Ag2S quantum dots (QDs) and NaYF4: Yb, Er upconversion nanoparticles (UCNPs) matched with BiOI for the simultaneous detection of TTX and OA in aquatic products. A low-cost, easily prepared gold nanoparticle-functionalized paper-based screen-printed electrode with six channels was designed to immobilize OA and Ab1 of TTX. Correspondingly, PEC signal immunoprobes (BiOI@UCNPs-Ab and Ab2-Ag2S QDs) with NIR-light response were introduced to construct competitive-type and sandwich-type PEC immunosensors for OA and TTX, respectively. Under optimal conditions, the linear ranges for TTX and OA were 0.001–100 and 0.001–80 ng mL−1, respectively, and the detection limits were 5 and 7 pg mL−1, respectively. The proposed sensor was successfully used for the simultaneous analysis of TTX and OA in Nassariidae samples.

A Near-Infrared-II Fluorescent Nanocatalyst for Enhanced CAR T Cell Therapy against Solid Tumor by Immune Reprogramming.

Chimeric antigen receptor (CAR) T cell therapy holds great promise in the treatment of hematological malignancies but performs poorly in solid tumors due to the tumor immunosuppressive microenvironment. Herein, a multifunctional nanocatalyst (APHA@CM) was prepared by encapsulating horseradish peroxidase (HRP)-loaded Au/polydopamine nanoparticles (Au/PDA NPs) and Ag2S quantum dots with CAR T cell membranes to improve the CAR T cell therapy in solid tumors. The APHA@CM has excellent multimodal imaging capability to precisely guide the scope and time window for nanocatalyst-induced tumor microenvironment regulation and CAR T cell therapy. The oxidase-like activity of Au NPs inhibited the glycolytic metabolism of tumor cells, reducing lactate efflux, reprogramming tumor immunosuppression, and ultimately increasing CAR T cell activation within the tumors. Additionally, the hypoxia environment of tumors could be relieved by HRP to enhance the Au/PDA NPs-induced synergistic sonodynamic/photothermal therapy (SDT/PTT), thereby promoting the immunogenic cell death of NALM 6 cells and enhancing CAR T cell-mediated immune microenvironment reprogramming. When this strategy was utilized to treat NALM 6 solid tumors, it not only completely eliminated tumors but also formed a long-term immune memory effect to inhibit tumor metastasis and recurrence. This work offers a strategy for CAR T cell therapy in solid tumor.

Ultrasonic enhancement of microdroplet-based interfacial reaction for improving the synthesis of Ag2S QDs

Ag2S quantum dots (QDs) have aroused extensive concerns in intravital imaging field due to their merits of narrow bandgap, low biological toxicity and decent fluorescence emission properties in the second near-infrared (NIR-II) window. However, low quantum yield (QY) and poor uniformity of Ag2S QDs are still main obstacles for its application. In this work, a novel strategy of utilizing ultrasonic field is presented, which can enhance the microdroplet-based interfacial synthesis of Ag2S QDs. The ultrasound increases the presence of ions at the reaction sites by enhancing the ion mobility in the microchennels. Therefore, the QY is enhanced from 2.33 % (optimal QY without ultrasound) to 8.46 %, which is the highest value of Ag2S ever reported without ion-doping. Also, the decrease of the corresponding full width at half maximum (FWHM) from 312 nm to 144 nm indicates the obvious uniformity improvement of the obtained QDs. Further mechanism exploration illustrates that ultrasonic cavitation significantly increases the interfacial reaction sites by splitting the droplets. Meanwhile, the acoustic flow field strengthens the ion renewal at the droplet interface. Consequently, the mass transfer coefficient increases by more than 500 %, which is favorable to improve both the QY and quality of Ag2S QDs. This work serves both fundamental research and practical production for the synthesis of Ag2S QDs.

Performance up-gradation of CIGS solar cell using Ag2S quantum dot as buffer layer

Performance up-gradation of CIGS solar cell using Ag2S quantum dot as buffer layer

Ultrasensitive Photoelectrochemical Immunoassay Strategy Based on Bi2S3/Ag2S for the Detection of the Inflammation Marker Procalcitonin

As an inflammatory marker, procalcitonin (PCT) is more representative than other traditional inflammatory markers. In this work, a highly efficient photoelectrochemical (PEC) immunosensor was constructed based on the photoactive material Bi2S3/Ag2S to realize the sensitive detection of PCT. Bi2S3 was prepared by a hydrothermal method, and Ag2S quantum dots were deposited on the ITO/Bi2S3 surface via in situ reduction. Bi2S3 is a kind of admirable photoelectric semiconductor nanomaterial on account of its moderate bandgap width and low binding rate of photogenerated electron holes, which can effectively convert light energy into electrical energy. Therefore, based on the energy level matching principle of Bi2S3 and Ag2S, a labeled Bi2S3/Ag2S PEC immunosensor was constructed, and the sensitive detection of PCT was successfully established. The linear detection range of the PEC immunosensor was 0.50 pg∙mL-1 to 50 ng∙mL-1, and the minimum detection limit was 0.18 pg∙mL-1. Compared with the traditional PEC strategy, the proposed PEC immunosensor is simple, convenient, and has good anti-interference, sensitivity, and specificity, which could provide a meaningful theoretical basis and reference value for the clinical detection of PCT.

High responsivity of VIS-NIR photodetector based on Ag2S/P3HT heterojunction

Ag2S quantum dot (QD) photodetectors (PDs) have attracted a lot of attention in the field of imaging system and optical communication. However, the current Ag2S PDs mainly works in the near-infrared band, and its detection ability in the visible band remains to be strengthened. In this paper, we used poly(3-hexylthiophene) (P3HT) with high carrier mobility and Ag2S QDs to construct heterojunction PD. Stronger absorption in blends with polymer P3HT compared to single Ag2S QDs. The optical absorption spectra show that the Ag2S/P3HT has strong light absorption peak at 394 and 598 nm. The results show that P3HT significantly enhances the absorption of Ag2S QDs from the visible to near-infrared band. The output characteristics, transfer characteristics and fast switching capability of the device at 405 nm, 532 nm and 808 nm were tested. The device has the responsivity of 6.05 A W−1, 83.72 A W−1 and 37.31 A W−1 under 405 nm, 532 nm and 808 nm laser irradiation. This work plays an important role in improving the detection performance of Ag2S QDs and broadening its applications in photoelectric devices for weak light and wide spectrum detection.

Water-soluble Ag2S QD modified CsPbI2Br heterojunction photodetector with ultra-low dark current and ultra-fast response speed

Mixed halide inorganic perovskite CsPbI3-xBrx has attracted attention in the field of optoelectronics. As a desirable photoactive material, the application of CsPbI2Br in the field of photodetector (PD) remains to be explored. The synergistic passivation strategy based on Ag2S quantum dot (QD) aqueous solution improves the morphology of the CsPbI2Br perovskite film. At the same time, Ag2S/CsPbI2Br bulk heterojunction optimizes the energy level arrangement between perovskite and Au electrode, improves the carrier transmission and collection capacity, and thus improves the performance of PD. Ag2S/CsPbI2Br bulk heterojunction PD has an ultra-low dark current of 7.74 pA, an ultra-fast response speed of 2.95/3.07 μs, and a high switching ratio of 7.67 × 105. This work provides a method for the preparation of high-quality mixed halide perovskite materials and a strategy for the development of high-performance perovskite PDs based on bulk heterojunction.

A redox reaction-induced ratiometric fluorescence platform for the specific detection of ascorbic acid based on Ag2S quantum dots and multifunctional CoOOH nanoflakes.

In this work, a ratiometric fluorescent nanoplatform for the detection of ascorbic acid (AA) was constructed based on the Ag2S quantum dots (QDs) and multifunctional hydroxyl cobalt oxide nanoflakes (CoOOH NFs). Ag2S QDs can be assembled on the surface of CoOOH NFs by electrostatic adsorption, resulting in the quenching of the NIR fluorescence emission of Ag2S QDs at 680 nm effectively through the inner filter effect (IFE). o-Phenylenediamine (OPD), a common substrate of oxidase-like (OXD) mimic, is rapidly oxidized into the fluorescent product of 2,3-diaminophenazine (DAP) with the appearance of an emission peak at 575 nm under the catalysis of CoOOH NFs. After AA was added, the fluorescence emission of DAP declined because of the decline in the OXD-like activity of CoOOH NFs due to the transformation of Co2+. Simultaneously, Ag2S QDs were released, accompanied by the recovery of red fluorescence. These two fluorescent signals can be excited at the same excitation wavelength, simplifying the detection procedure. Using F575/F680 as the readout, the quantification of AA can be realized with the linear range and detection limit of 0.2 μM-20 mM and 0.014 μM, respectively. The ratiometric fluorescence sensor can be effectively used to determine the content of AA in real samples such as juice and serum. This work integrates the in-situ formation of the fluorescent species via the catalysis of the nanozyme and the redox reaction to destroy the CoOOH NFs nanozyme as well as the two dimensional nanoflake induced turn-off-on strategy for Ag2S QDs, which provides a specific strategy for the selective detection of AA and may offer a reliable approach for the construction of other biosensing platforms.

Using host-guest interactions at the interface of quantum dots to load drug molecules for biocompatible, safe, and effective chemo-photodynamic therapy against cancer.

Combining photodynamic therapy (PDT) and chemotherapy (CHT) by loading an anti-cancer drug and a photosensitizer (PS) into the same delivery nanosystem has been proposed as an effective approach to achieve synergistic effects for a safe cancer treatment. However, exploring an ideal delivery nanosystem has been challenging, because the noncovalent interactions must be maintained between the multiple components to produce a stable yet responsive nanostructure that takes into account the encapsulation of drug molecules. We addressed this issue by engineering the interfacial interaction between Ag2S quantum dots (QDs) using a pillararene derivative to direct the co-self-assembly of the entire system. The high surface area-to-volume ratio of the Ag2S QDs provided ample hydrophobic space to accommodate the anti-drug molecule doxrubicine. Moreover, Ag2S QDs served as PSs triggered by 808 nm near-infrared (NIR) light and also as carriers for high-efficiency delivery of drug molecules to the tumor site. Drug release experiments showed smart drug release under the acidic microenvironments (pH 5.5) in tumor cells. Additionally, the Ag2S QDs demonstrated outstanding PDT ability under NIR light, as confirmed by extracellular and intracellular reactive oxygen species generation. Significant treatment efficacy of the chemo-photodynamic synergistic therapy for cancer using the co-delivery system was demonstrated via in vitro and in vivo studies. These findings suggest that our system offers intelligent control of CHT and PDT, which will provide a promising strategy for constructing hybrid systems with synergistic effects for advanced applications in biomedicine, catalysis, and optoelectronics.

Highly Efficient GSH-Responsive "Off-On" NIR-II Fluorescent Fenton Nanocatalyst for Multimodal Imaging-Guided Photothermal/Chemodynamic Synergistic Cancer Therapy.

Accurate diagnosis and effective treatment of malignant tumors under the interference of complex and diverse tumor microenvironments (TMEs) have become the focus of research. Herein, an innovative TME-activated biomimetic nanocatalyst with quad-modal imaging capabilities of second near-infrared (NIR-II) "turn-on" fluorescence imaging, magnetic resonance imaging (MRI), photoacoustic imaging (PAI), and photothermal imaging (PTI) was designed and developed for self-enhanced photothermal/chemodynamic synergistic therapy. The catalyst was fabricated by loading glucose oxidase (GOD) and Ag2S quantum dots (QDs) on MnO2 nanosheets and coating them with a 4T1 cell membrane (AMG@CM), which enables them to successfully escape immune clearance and have appealing tumor-targeting ability and biocompatibility. The NIR-II fluorescence at 1130 nm of Ag2S QDs quenched by MnO2 could be recovered in vivo through the glutathione (GSH)-induced degradation of MnO2, enabling excellent TME-responsive tumor visualization. Simultaneously, the released Mn2+ can catalyze H2O2 to produce abundant hydroxyl radicals (•OH), achieving photothermal synergistically enhanced chemodynamic therapy (CDT) under NIR-II radiation. Moreover, the CDT could be self-enhanced by GOD due to the extra produced H2O2. This work demonstrates a novel and highly efficient multimodal imaging-guided integrated treatment strategy for dual-enhanced CDT tumor precise diagnosis and treatment.

Stimuli‐Responsive Hybrid Vesicle for Tumor Dual‐Model NIR‐II Photoacoustic and Fluorescence Imaging and Precise Radiotherapy

AbstractBioimaging guided‐radiotherapy is widely investigated as one of the mainstream cancer theranostic strategies for precision medicine. Nevertheless, background noise with “always‐on” imaging signal and inadequate tumor enrichment restrict disease diagnosis and therapy. Here, a nanogapped gold nanoparticles (AuNNPs)–silver sulfide (Ag2S) vesicle (Ve) is designed as a “biological switch” through the self‐assembly of pH‐responsive polymer thiolated polystyrene‐co‐poly(4‐vinylpyridine) grafted AuNNPs and Ag2S quantum dots (QDs). The AuNNPs–Ag2S Ve exhibits quenched NIR‐II fluorescence (FL) and enhanced photoacoustic signals initially, which can be specifically activated by an acidic environment to release Ag2S QDs and “turn on” NIR‐II FL signal in the second near‐infrared (NIR‐II, 950–1700 nm) window. Besides, the strategy of disease‐located NIR‐II imaging guided cancer therapy can remarkably enhance the therapeutic efficacy of radiotherapy, as well as minimize side effects. Such an intelligent nanoplatform with the ability of stimulus activated NIR‐II imaging guided radiotherapy shows great promise to precision biomedicine in the future.

Transformation of Trap States during the Formation of Luminescent Core/Shell Nanostructures Based on Ag2S Quantum Dots

Transformation of Trap States during the Formation of Luminescent Core/Shell Nanostructures Based on Ag2S Quantum Dots

Multifunctional nanocarrier with self-catalytic production of nitric oxide for photothermal and gas-combined therapy of tumor

Single treatment often faces the problem that it cannot completely eradicate tumor and inhibit the tumor metastasis. In order to overcome this shortcoming, multi-modal tumor treatment has attracted widespread attention. In the present article, based on ascorbyl palmitate (PA) and l-arginine (l-Arg), a multifunctional nanocarrier is designed for synergetic treatment of tumor with photothermal and nitric oxide (NO) gas therapy. Firstly, PA and l-Arg were self-assembled to form novel functional micelles, PL, with high biosafety using electrostatic interaction and hydrogen bonding. The functional micelles could self-catalyze to produce NO at the tumor site. Then, Ag2S quantum dots having fluorescence imaging and photothermal properties were encapsulated to obtain the nanocarrier, A@PL. The results show that A@PL had a hydrated size of around 78 nm and presented good stability within 30 d. Moreover, in vitro studies indicate that it was efficient with regards to NO self-generating capacity, whereas the photothermal conversion efficiency was as high as 34% under near-infrared light irradiation. The cytotoxicity results show that, when the concentration of A@PL was as high as 2 mM, the survival rate of 3 T3 cells was still 78.23%, proving that the probe has good safety characteristics. Fluorescence imaging results show that its maximum enrichment can be achieved at the tumor site after tail vein injection for 3 h, and out of the body after 24 h, indicating good internal circulation. The in vivo studies show that the rate of inhibition of tumor using the nanocarrier was as high as 98%, and almost overcame the problem of tumor recurrence caused by single treatment, thus presenting a significant tumor treatment effect. This new multifunctional nanocarrier with self-catalytic production of NO provides a new idea for the efficient treatment of tumors.

Engineering of multifunctional carbon nanodots-decorated plasmonic Au@Ag nanoenzymes for photoelectrochemical biosensing of microRNA-155

Herein, the multifunctional carbon nanodots (CDs)-decorated plasmonic Au@Ag nanoenzymes coupled with Ti2C/Ag2S composites were proposed for photoelectrochemical (PEC) biosensing of microRNA. Two-dimensional (2D) Ti2C MXenes-sensitized Ag2S quantum dots (QDs) (Ti2C/Ag2S composites) acquired an initial photocurrent. After immobilization of a hairpin subsidiary probe (S1) onto the Ti2C/Ag2S composites photoelectrode surface, the target microRNA-associated bipedal DNA walker performed the opening of S1 for forming triple helix molecules. Then the CDs-decorated Au@Ag core–shell (Au@Ag@CDs) nanocuboids were introduced into the PEC biosensing platform through target-induced triple helix molecules. The Au@Ag@CDs nanocuboids as a multifunctional signal amplifier not only competitively captured the irradiating light and electron donors to weaken the PEC signal, but also quenched the photocurrent response resulting from energy transfer between plasmonic bimetallic Au@Ag nanocuboids and Ag2S QDs. Additionally, the Au@Ag and CDs in Au@Ag@CDs nanocuboids displayed a synergistic catalytic effect, and could serve as peroxidase nanoenzymes to catalyze the production of precipitates onto the biosensor surface, resulting in a significantly decreased photocurrent. Based on the plasmonic Au@Ag@CDs nanoenzymes coupled with Ti2C/Ag2S composites, microRNA-155 was ultrasensitively detected with a wide linear range (1–10,000 fM) and a low limit of detection (0.83 fM). Moreover, the engineered plasmonic Au@Ag@CDs nanoenzymes offer an environmentally friendly and multifunctional signal amplifier for fabricating PEC biosensor and have potential applications in biomarkers detection and disease diagnostics.

A self-assembled nanoplatform based on Ag2S quantum dots and tellurium nanorods for combined chemo-photothermal therapy guided by H2O2-activated near-infrared-II fluorescence imaging

A nanoplatform based on Ag2S quantum dots (QDs) and tellurium nanorods (TeNRs) was developed for combined chemo-photothermal therapy guided by H2O2-activated near-infrared (NIR)-II fluorescence imaging. Polypeptide PC10AGRD-modified TeNRs and Ag2S QDs were co-encapsulated in 4T1 cell membrane to prepare a nanoplatform (CCM@AT). Ag2S QDs and TeNRs in the CCM@AT were used as a fluorescence probe and photosensitizer, and a chemotherapeutic prodrug and quenching agent to quench the fluorescence of Ag2S QDs, respectively. After the CCM@AT was specifically targeted to the tumor site, the TeNRs were dissolved by the high concentration of H2O2 at the tumor site to light up the fluorescence of Ag2S QDs for NIR-II fluorescence imaging. In addition, the generated toxic TeO66− molecules decreased ATP production by selective cancer chemotherapy, which is beneficial for photothermal therapy. The elevated temperature due to photothermal therapy in turn promoted the chemical reaction in chemotherapy. In vitro and in vivo toxicity results showed that the CCM@AT possesses high biocompatibility. Compared to single photothermal therapy and chemotherapy, the synergistic chemo-photothermal therapy can effectively suppress the growth of 4T1 tumor. This all-in-one nanoplatform provides a boulevard for the combination therapy of tumors guided by NIR-II fluorescence imaging. Statement of significanceNIR-II fluorescence imaging shows the characteristics of low tissue absorption, reflection, and scattering, which can greatly reduce the influence of autofluorescence in vivo. However, the non-negligible effect of autofluorescence is still observed in fluorescence imaging in vivo. Therefore, there is an urgent need to develop a strategy of controlled release of fluorescence for accurate imaging and tumor therapy. Here, Ag2S quantum dots (QDs) with NIR-II fluorescence emission and good photothermal conversion efficiency are used as a fluorescence probe and photosensitizer, and tellurium nanorods (TeNRs) are used as a chemotherapeutic prodrug and quenching agent to quench the fluorescence of Ag2S QDs. This multiple nanoplatform provides an inspiration for the combination therapy of tumor guided by NIR-II fluorescence imaging.

Laser‐Assisted Synthesis of Ag2S‐Quantum‐Dot‐in‐Perovskite Matrix and Its Application in Broadband Photodetectors

AbstractHalide perovskites are widely explored as efficient photoresponsive materials for optoelectronic devices. However, understanding and controlling their underlying optical and electrical properties remains limited. Here, a novel approach is developed by introducing silver sulfide (Ag2S) quantum dots (QDs) into an MAPbBr3 single crystal. The high‐quality Ag2S‐quantum‐dot‐in‐perovskite (Ag2S‐QDiP) matrixes synthesized through a laser‐assisted inverse temperature crystallization (LA‐ITC) strategy show broadband light‐sensitive wavelength from 550 to over 1000 nm, and a balanced carriers mobility facilitates their transmission and collection. A Ag2S‐QDiP‐enabled photodetector is demonstrated, which exhibits considerably enhanced responsivity and detectivity of 1.17 A W−1 and 6.24 × 1014 Jones at 532 nm, and 57.69 mA W−1 and 1.03 × 1011 Jones at 1064 nm, respectively. The enhanced performance in the near‐infrared (NIR) region can be attributed to the discrete heterojunction formed between MAPbBr3 and Ag2S QDs, which enhances the light absorption in the NIR range and facilitates photogenerated excitons’ separation at the interface. The facile synthesis process, the more balanced transport behavior, and the ensuing improved device performance highlight introducing QDs into perovskite single crystal as an efficient strategy for tuning fundamental properties of perovskite and for developing high‐efficiency broadband electronic and optoelectronic devices.