Near Infrared-II Excited Triplet Fusion Upconversion with Anti-Stokes Shift Approaching the Theoretical Limit.

The anti-Stokes shift represents the capacity of photon upconversion to convert low-energy photons to high-energy photons. Although triplet exciton-mediated photon upconversion presents outstanding performance in solar energy harvesting, photoredox catalysis, stereoscopic 3D printing, and disease therapeutics, the interfacial multistep triplet exciton transfer leads to exciton energy loss to suppress the anti-Stokes shift. Here, we report near infrared-II (NIR-II) excitable triplet exciton-mediated photon upconversion using a hybrid photosensitizer consisting of lead sulfide quantum dots (PbS QDs) and new surface ligands of thiophene-substituted diketopyrrolopyrrole (Th-DPP). Under 1064 nm excitation, this photon upconversion revealed a record-corrected upconversion efficiency of 0.37% (normalized to 100%), with the anti-Stokes shift (1.07 eV) approaching the theoretical limit (1.17 eV). The observation of this unexpected result is due to our discovery of the presence of a weak interaction between the sulfur atom on Th-DPP and Pb2+ on the PbS QDs surface, facilitating electronic coupling between PbS QDs and Th-DPP, such that the realization of triplet exciton transfer efficiency is close to 100% even when the energy gap is as small as 0.04 eV. With this premise, this photon upconversion as a photocatalyst enables the production of standing organic gel via photopolymerization under 1064 nm illumination, displaying NIR-II photon-driven photoredox catalysis. This research not only establishes the foundation for enhancing the performance of NIR-II excitable photonic upconversion but also promotes its development in photonics and photoredox catalysis.

Deciphering Oxygen-Independent Augmented Photodynamic Oncotherapy by Facilitating the Separation of Electron-Hole Pairs.

Developing Type-I photosensitizers provides an attractive approach to solve the dilemma of inadequate efficacy of photodynamic therapy (PDT) caused by the inherent oxygen consumption of traditional Type-II PDT and anoxic tumor microenvironment. The challenge for the exploration of Type-I PSs is to facilitate the electron transfer ability of photosensitization molecules for transforming oxygen or H2O to reactive oxygen species (ROS). Herein, we propose an electronic acceptor-triggered photoinduced electron transfer (a-PET) strategy promoting the separation of electron-hole pairs by marriage of two organic semiconducting molecules of a non-fullerene scaffold-based photosensitizer and a perylene diimide that significantly boost the Type-I PDT pathway to produce plentiful ROS, especially, inducing 3.5-fold and 2.5-fold amplification of hydroxyl (OH⋅) and superoxide (O2 -⋅) generation. Systematic mechanism exploration reveals that intermolecular electron transfer and intramolecular charge separation after photoirradiation generate a competent production of radical ion pairs that promote the Type-I PDT process by theoretical calculation and ultrafast femtosecond transient absorption (fs-TA) spectroscopy. By complementary tumor diagnosis with photoacoustic imaging and second near-infrared fluorescence imaging, this as-prepared nanoplatform exhibits fabulous photocytotoxicity in harsh hypoxic conditions and terrific cancer revoked abilities in living mice. We envision that this work will broaden the insight into high-efficiency Type-I PDT for cancer phototheranostics.

Highly Twisted Conformation Thiopyrylium Photosensitizers for In Vivo Near Infrared-II Imaging and Rapid Inactivation of Coronavirus.

Despite significant effort, a majority of heavy-atom-free photosensitizers have short excitation wavelengths, thereby hampering their biomedical applications. Here, we present a facile approach for developing efficient near-infrared (NIR) heavy-atom-free photosensitizers. Based on a series of thiopyrylium-based NIR-II (1000-1700 nm) dyads, we found that the star dyad HD with a sterically bulky and electron-rich moiety exhibited configuration torsion and significantly enhanced intersystem crossing (ISC) compared to the parent dyad. The electron excitation characteristics of HD changed from local excitation (LE) to charge transfer (CT)-domain, contributing to a ≈6-fold reduction in energy gap (ΔEST ), a ≈10-fold accelerated ISC process, and a ≈31.49-fold elevated reactive oxygen species (ROS) quantum yield. The optimized SP@HD-PEG2K lung-targeting dots enabled real-time NIR-II lung imaging, which precisely guided rapid pulmonary coronavirus inactivation.

Generating New Cross-Relaxation Pathways by Coating Prussian Blue on NaNdF4 To Fabricate Enhanced Photothermal Agents.

Cross-relaxation among sensitizers is commonly regarded as deleterious in fluorescent materials, although favorable in photothermal agents. Herein, we coated Prussian blue (PB) on NaNdF4 nanoparticles to fabricate core-shell nanocomplexes with new cross relaxation pathways between the ladder-like energy levels of Nd3+ ions and continuous energy band of PB. The photothermal conversion efficiency was improved exceptionally and the mechanism of the enhanced photothermal effect was investigated. In vivo photoacoustic imaging and photothermal therapy demonstrated the potential of the enhanced photothermal agents. Moreover, the concept of generating new cross-relaxation pathways between different materials is proposed to contribute to the design of all kinds of enhanced photothermal agents.

MicroRNA-425-5p regulates chemoresistance in colorectal cancer cells via regulation of Programmed Cell Death 10.

Acquired chemoresistance represents a major obstacle in cancer treatment, the underlying mechanism of which is complex and not well understood. MiR-425-5p has been reported to be implicated tumorigenesis in a few cancer types. However, its role in regulating chemoresistance has not been investigated in colorectal cancer (CRC) cells. Microarray analysis was performed in isogenic chemosensitive and chemoresistant HCT116 cell lines to identify differentially expressed miRNAs. miRNA quantitative real-time PCR was used to detect miR-425-5p expression levels between drug resistant and parental cancer cells. MiR-425-5p mimic and inhibitor were transfected, followed by CellTiter-Glo(®) assay to examine drug sensitivity in these two cell lines. Western Blot and luciferase assay were performed to investigate the direct target of miR-425-5p. Xenograft mouse models were used to examine in vivo function of miR-425-5p. Our data showed that expression of miR-425-5p was significantly up-regulated in HCT116-R compared with parental HCT116 cells. Inhibition of miR-425-5p reversed chemoresistance in HCT116-R cells. Programmed cell death 10 (PDCD10) is the direct target of miR-425-5p which is required for the regulatory role of miR-425-5p in chemoresistance. MiR-425-5p inhibitor sensitized HCT116-R xenografts to chemo drugs in vivo. Our study demonstrated that miR-425-5p regulates chemoresistance of CRC cells by modulating PDCD10 expression level both in vitro and in vivo. MiR-425-5p may represent a new therapeutic target for the intervention of CRC.

Identification of ß-glucosidase 1 as a biomarker and its high expression in hepatocellular carcinoma is associated with resistance to chemotherapy drugs.

CONTEXT AND OBJECTIVE: Long-term prognosis of hepatocellular carcinoma (HCC) patients is challenging, and novel biomarkers are needed to predict patient risk and serve as potential therapeutic target. RESULTS: We found ß-glucosidase 1 is significantly overexpressed and activated in primary HCC tissue and multiple HCC cell lines. ß-Glucosidase 1 expression is associated with predicting prognosis of HCC patients under chemotherapy. Silencing ß-glucosidase 1 inhibits growth and survival of HCC cells, with preferential inhibitory effects on high ß-glucosidase 1-expressing cells. Combination of chemo drug with ß-glucosidase 1 inhibitor sensitized HCC cells to chemotherapy. CONCLUSION: Our data support ß-glucosidase 1 as a HCC biomarker due to its prognosis significance.

Photostable Organic Two-photon Dyes with Ultrahigh Brightness for Long-term Fluorescence Imaging.

Developing photostable two-photon dyes with high brightness and negligible photocytotoxicity is of key importance in fluorescence imaging but remains a huge challenge. Here, a two-photon dye with ultrahigh brightness and photostability is demonstrated for high-performance long-term two-photon fluorescence imaging. By terminated donor engineering, the designed DBD shows a higher two-photon absorption cross-section (δ, 418 GM vs 329 GM) and photoluminescence quantum yield (ΦPL , 62.74% vs 54.63%) than its counterpart DBA. As a consequence, two-photon fluorescence brightness (δ×ΦPL ) of DBD exhibits a 10-folded enhancement (262 GM vs 19 GM) in comparison with typical Coumarin 307 dye. More importantly, DBD displays ultrahigh photostability and negligible photobleaching under 10 min femtosecond laser irradiation, which stands in marked contrast to Coumarin 307. Furthermore, femtosecond transient absorption spectroscopy ascribes this ultrahigh photostability and negligible photobleaching to the inefficient intersystem crossing. With these merits, DBD can be used long-term two-photon fluorescence imaging in vitro.

Excimer-Mediated Ultrafast Intermolecular Nonradiative Decay Enables Giant Photothermal Performance for Optimized Phototheranostic.

Developing organic photothermal materials (OPMs) with high photothermal performance for phototheranostic mainly focus on the manipulation of intramolecular nonradiative (intraNR) decay, which often requires quite complicated and time-consuming molecular engineering. In addition to intraNR decay, intermolecular nonradiative (interNR) decay is equally important and more convenient in governing photothermal performance. However, controlling interNR decay remains challenging due to the limited understanding of their origin and dynamics. Here, systemic investigation of intraNR and interNR decay directs the first demonstration of simple manipulation of interNR decay to produce a giant photothermal performance for optimized phototheranostic. Among three designed polymers with varying fluorine substitution, structure-performance studies reveal a dimer-initiated interNR decay to improve photothermal performance. Dimer is formed by intermolecular CF···H hydrogen bond. This finding inspires a simple aggregation control strategy to form excited dimer, namely, excimer. It initiates an ≈100-fold enhancement in interNR decay rate over conventional intraNR decay to produce ultrahigh photothermal conversion efficiency of 81% for efficient photoacoustic imaging-guided photothermal therapy in vivo. This study provides insights into interNR decay in achieving a giant photothermal effect and paves a convenient way to develop high-performance OPMs.

Acceptor Engineering Produces Ultrafast Nonradiative Decay in NIR-II Aza-BODIPY Nanoparticles for Efficient Osteosarcoma Photothermal Therapy via Concurrent Apoptosis and Pyroptosis.

Small-molecule photothermal agents (PTAs) with intense second near-infrared (NIR-II, 1,000 to 1,700 nm) absorption and high photothermal conversion efficiencies (PCEs) are promising candidates for treating deep-seated tumors such as osteosarcoma. To date, the development of small-molecule NIR-II PTAs has largely relied on fabricating donor-acceptor-donor (D-A-D/D') structures and limited success has been achieved. Herein, through acceptor engineering, a donor-acceptor-acceptor (D-A-A')-structured NIR-II aza-boron-dipyrromethene (aza-BODIPY) PTA (SW8) was readily developed for the 1,064-nm laser-mediated phototheranostic treatment of osteosarcoma. Changing the donor groups to acceptor groups produced remarkable red-shifts of absorption maximums from first near-infrared (NIR-I) regions (~808 nm) to NIR-II ones (~1,064 nm) for aza-BODIPYs (SW1 to SW8). Furthermore, SW8 self-assembled into nanoparticles (SW8@NPs) with intense NIR-II absorption and an ultrahigh PCE (75%, 1,064 nm). This ultrahigh PCE primarily originated from an additional nonradiative decay pathway, which showed a 100-fold enhanced decay rate compared to that shown by conventional pathways such as internal conversion and vibrational relaxation. Eventually, SW8@NPs performed highly efficient 1,064-nm laser-mediated NIR-II photothermal therapy of osteosarcoma via concurrent apoptosis and pyroptosis. This work not only illustrates a remote approach for treating deep-seated tumors with high spatiotemporal control but also provides a new strategy for building high-performance small-molecule NIR-II PTAs.

Viscosity Effects on Excited-State Dynamics of Indocyanine Green for Phototheranostic.

The excited-state dynamics of indocyanine green (ICG) fundamentally determine its photophysical properties for phototheranostic. However, its dynamics are predictable to be susceptible toward intracellular viscosity due to its almost freely rotating structure, making the precise phototheranostic very challenging. Therefore, correlating the viscosity with the dynamics of ICG is of great importance and urgency for precise phototheranostic prospects. This study presents systemic investigations on the viscosity-dependent dynamics of ICG for phototheranostic. Femtosecond transient absorption (fs-TA) experiments elucidate a prolonged radiative transition (225 ps vs 152 ps) for ICG in a viscous environment, which benefits fluorescence. High viscosity remarkably extends the triplet excited-state lifetime of ICG but reduces its internal conversion (6.2 ps vs 2.2 ps). The extended triplet lifetime affords sufficient photosensitization time to enhance photodynamic therapy. A moderative internal conversion is unfavorable for heat production, resulting in inferior photothermal therapy. With this clear picture of excitation energy state dissipation in mind, we readily identified the safety laser power density for precise phototheranostic. This work provides an insightful understanding of viscosity-relevant excited-state dynamics toward phototheranostic, which is also beneficial for designing novel ICG derivatives with improved phototheranostic performance.

Inhibition of indoleamine 2,3-dioxygenase 1 synergizes with oxaliplatin for efficient colorectal cancer therapy.

We investigated the immunogenic cell death provoked by oxaliplatin (OXA) and the involvement of OXA-induced immunosuppression in colorectal cancer. Immune-proficient or -deficient mice were employed to evaluate the therapeutic effects of OXA. Immunogenic cell death was characterized by cell-surface calreticulin, cytosol-translocated high migration rate group protein B1 (HMGB1), and secretory ATP content. Bone marrow-derived dendritic cell (BMDC) maturation and CD8+ T cell expansion were measured by flow cytometry. Expression of immunosuppressive genes was quantified by both RT-PCR and western blots. The proliferative and apoptotic indexes of xenograft tumors were evaluated by immunohistochemistry and TUNEL assays, respectively. The secretory cytokines were measured with ELISA. OXA induced immunogenic cell death of murine colorectal cancer, which greatly depended on the host immune response. OXA-pretreated CT26 cells promoted BMDC maturation and CD8+ T cell expansion. OXA significantly upregulated indoleamine 2,3-dioxygenase 1 (IDO1) in patient-derived colorectal cancer cells and in combination with the IDO1-specific inhibitor, NLG919, suppressed tumor progression. Simultaneous administration with both OXA and NLG919 greatly promoted CD8+ T cell infiltration and decreased immunosuppressive cytokine transforming growth factor ß (TGF-ß) production, whereas increased immunostimulatory cytokines interleukin (IL)-12p70 and interferon (IFN)-γ. We demonstrated the upregulation of IDO1 by OXA, which combined with the IDO1 inhibitor, tremendously potentiated therapeutic effects of OXA against colorectal cancer.

Long Non-coding RNA SENP3-EIF4A1 Functions as a Sponge of miR-195-5p to Drive Triple-Negative Breast Cancer Progress by Overexpressing CCNE1.

Triple-negative breast cancer (TNBC) has high malignancy and limited treatment, so novel molecular therapeutic targets are urgently needed. Cyclin E1 (CCNE1) promotes progression in breast cancer, but its role and inherent mechanisms in TNBC are yet to be elucidated. Competing endogenous RNA (ceRNA) may be a potential mechanism. CCNE1 was selected though bioinformatics and clinical samples, and cell lines were utilized to verify CCNE1 expression by qRT-PCR and western blot. Predicting tools provided potential miR-195-5p and SENP3-EIF4A1 and tested from multilevel. Functional experiments were conducted in vitro and in vivo. Luciferase reporter assay and RNA immunoprecipitation experiments were implemented to ensure the interaction between miR-195-5p and SENP3-EIF4A1/CCNE1 in TNBC. Bioinformatics found DNA hypermethylation of miR-195-5p and preliminarily verified. Mechanistically, SENP3-EIF4A1-miR-195-5p-associated ceRNA could drive TNBC progress though regulating CCNE1. DNA hypermethylation of miR-195-5p might be another reason. In summary, SENP3-EIF4A1-miR-195-5p-CCNE1 axis promotes TNBC progress and may contribute to the novel diagnosis and treatment of TNBC.

Circ-SMARCA5 suppresses colorectal cancer progression via downregulating miR-39-3p and upregulating ARID4B.

BACKGROUND: Circular RNAs are crucial in tumorigenesis. However, little is known about their functions in colorectal cancer (CRC). Circ-SMARCA5 was found to be an oncogene or tumor suppresser in different types of cancers, but its exact role in CRC remains unknown. Here, we aim to identify the role of circ-SMARCA5 in CRC development. METHODS: Circ-SMARCA5 expression was determined by qRT-PCR. CRC cell proliferation, migration, and invasion were detected by CCK-8, wound healing, and Transwell assays, respectively. Bioinformatics analysis was performed to predict target genes. The interaction of microRNA (miR) with circ-SMARCA5 or target genes was detected using luciferase reporter assay. Xenograft model was established to determine the effect of circ-SMARCA5 on CRC tumor growth in vivo. RESULTS: Circ-SMARCA5 expression was dramatically decreased in CRC cell lines and tissues. Circ-SMARCA5 overexpression inhibited CRC cell proliferation, migration and invasion. MiR-93-3p was predicted as a target of circ-SMARCA5 and its overexpression attenuated the anti-tumor effect of circ-SMARCA5 on CRC cells. Furthermore, we predicted AT-rich interaction domain 4B (ARID4B) as the target of miR-39-3p. Functional analysis showed that circ-SMARCA5 upregulated ARID4B expression via miR-39-3p. Additionally, in vivo studies demonstrated that circ-SMARCA5 suppressed CRC tumor progression. CONCLUSION: Circ-SMARCA5 functions as a tumor suppressor by upregulating ARID4B expression via sponging miR-39-3p, and thereby inhibited CRC progression.

Epithelial ovarian cancer stem­like cells are resistant to the cellular lysis of cytokine­induced killer cells via HIF1A­mediated downregulation of ICAM­1.

Epithelial ovarian cancer (EOC) is the most lethal of all gynecologic tumors. Cancer spheroid culture is a widely used model to study cancer stem cells. Previous studies have demonstrated the effectiveness of cytokine­induced killer (CIK) cell­based therapies against cancer and cancer stem cells. However, it is not clear how EOC spheroid cells respond to CIK­mediated cellular lysis, and the mechanisms involved have never been reported before. A flow cytometry­based method was used to evaluate the anti­cancer effects of CIK cells against adherent A2780 cells and A2780 spheroids. To demonstrate the association between hypoxia inducible factor­1α (HIF1A) and intercellular adhesion molecule­1 (ICAM­1), two HIF1A short hairpin RNA (shRNA) stable transfected cell lines were established. Furthermore, the protein expression levels of hypoxia/HIF1A­associated signaling pathways were evaluated, including transforming growth factor­ß1 (TGF­ß1)/mothers against decapentaplegic homologs (SMADs) and nuclear factor­κB (NF­κB) signaling pathways, comparing A2780 adherent cells and cancer spheroids. Flow cytometry revealed that A2780 spheroid cells were more resistant to CIK­mediated cellular lysis, which was partially reversed by an anti­ICAM­1 antibody. HIF1A was significantly upregulated in A2780 spheroids compared with adherent cells. Using HIF1A shRNA stable transfected cell lines and cobalt chloride, it was revealed that hypoxia/HIF1A contributed to downregulation of ICAM­1 in A2780 spheroid cells and adherent cells. Furthermore, hypoxia/HIF1A­associated signaling pathways, TGF­ß1/SMADs and NF­κB, were activated in A2780 spheroid cells by using western blotting. The findings indicate that EOC stem­like cells resist the CIK­mediated cellular lysis via HIF1A­mediated downregulation of ICAM­1, which may be instructive for optimizing and enhancing CIK­based therapies.

Enhancing the Efficiency of Graphene Oxide Reduction in Low-Power Digital Video Disc Drives by a Simple Precursor Heat Treatment.

Laser reduction of graphene oxide (GO) produces graphene effectively. As a low-power laser source, commercial digital video disc (DVD) drives provide a versatile platform to produce reduced graphene films in designed 2D patterns. However, research on how GO characteristics affect its laser reduction efficiency in DVD drives is rarely conducted. Here, we investigate how heating the GO dispersion affects the photoreduction process of GO films in a LightScribe DVD drive. Without noticeably changing the oxygen content, such mild heat treatment significantly improves GO's absorption in the visible region, resulting in significant enhancement on GO's laser reduction efficiency. We demonstrate that the laser reduction efficiency increases with the increasing treatment time. The enhanced reduction level greatly improves the performance of laser-scribed graphene electrodes in applications such as glucose sensors (with an optimal linear response range up to 2550 µM) and supercapacitors (with an optimal areal capacity of 1.37 mF cm-2 at the scan rate of 50 mV s-1). This proposed approach provides general insights into the production of laser-reduced graphene with low-power laser sources, for advanced device applications such as wearable electronics and flexible microelectronics.

A near-infrared I emissive dye: toward the application of saturable absorber and multiphoton fluorescence microscopy in the deep-tissue imaging window.

A boron-dipyrromethene (BODIPY) dye emitting in the near-infrared (NIR) I region (723 nm) exhibits strong saturable absorption at 680 nm. Its multiphoton absorption spectra in the NIR II and III regions are determined. Three-photon fluorescence imaging of the BODIPY-labeled cells excited at 1665 nm is also demonstrated.

Manipulating Nonradiative Decay Channel by Intermolecular Charge Transfer for Exceptionally Improved Photothermal Conversion.

In-depth studies of nonradiative (NR) decay, seeking to maximize NR decay rate or manipulate other NR decay channels, are of greatest significance for improving the photothermal conversion efficiency (η) of organic materials for phototheranostics; however, to date, relevant work remains scarce. Here, we present an insightful study of NR decay in BODIPY (BDP) dye, in an aggregated state, i.e., in BDP nanoparticles (BDP NPs), which show an efficient additional NR decay channel from the aggregation-stabilized intermolecular charge transfer (CT) state, resulting in exceptionally high η (61%) for highly efficient phototheranostics in vivo. BDP NPs exhibit two ultrafast NR decay channels with ultrashort lifetimes of 1.7 and 50 ps, which is in stark contrast to the only S1 → S0 NR channel with a long lifetime of 373 ps in the isolated BDP dye. More importantly, the ultrafast NR channel (1.7 ps) in BDP NPs depletes a substantial portion of the excited-state population (71%), which accounts for its much better photothermal effect as compared with the isolated BDP dye. Finally, BDP NPs display a highly efficient photoacoustic imaging (PAI) guided photothermal therapy (PTT) of tumors in live mice. This study presents a deeper fundamental understanding of NR decay in organic materials, setting a valuable guideline that may be widely applicable to similar molecular structure to develop more advanced organic materials not only for photothermal-related applications.

Deciphering the intersystem crossing in near-infrared BODIPY photosensitizers for highly efficient photodynamic therapy.

Deciphering singlet-to-triplet intersystem crossing (ISC) in organic near-infrared photosensitizers (PSs) is of fundamental importance in the designing of high-performance PSs to boost the clinical usage of photodynamic therapy (PDT). However, in-depth investigations of the ISC dynamics in near-infrared PSs have not been performed to date. Here, systematical investigations of the ISC dynamics in organic near-infrared BODIPY derivatives are presented, in which a multi-channel yet remarkably efficient ISC process is revealed by ultrafast femtosecond transient absorption (fs-TA) spectroscopy and theoretical calculation. The fs-TA verifies an exceptionally enhanced ISC efficiency (Φ ISC = 91%) in iodine-substituted BODIPY (2I-BDP) which is further supported by the calculation results. This endows 2I-BDP with an ultrahigh singlet oxygen quantum yield (Φ Δ = 88%), thus enabling a proof-of-concept application of highly efficient PDT in vivo under ultralow near-infrared light power density (10 mW cm-2). The in-depth understanding of ISC dynamics in organic near-infrared materials may provide valuable guidance in the designing of novel organic theranostic materials for clinical cancer treatment.

Two-Photon-Induced Charge-Variable Conjugated Polyelectrolyte Brushes for Effective Gene Silencing.

Cationic conjugated polyelectrolytes can absorb negatively charged small interfering RNA (siRNA) and also visualize the cellular internalization of siRNA, which thus have been extensively explored as siRNA carriers. However, their low charge density cannot afford a high carrying capability, severely impeding gene transfection efficiency. Moreover, the intracellular controlled release of siRNA is another factor that limits the widespread use of siRNA therapeutics. Herein, we present a novel two-photon-induced charge-variable conjugated polyelectrolyte brush as an efficient siRNA carrier. This cationic conjugated polyelectrolyte brush (PPENBr-ONB) with densely cationic charges produces remarkable carrying capability with siRNA. In addition, PPENBr-ONB with large two-photon absorption (TPA) cross-section represents effective fluorescence resonance energy transfer (FRET) to photoresponsive side chain with 720 nm illumination for two-photon-induced photolysis. Hence, the charge transformation of the photoresponsive side chain from cations to zwitterions would remarkably elevate siRNA release. The obtained PPENBr-ONB shows considerable fluorescence quantum yields (0.16) in aqueous solution, sufficient to serve as a reporter for cellular imaging. Agarose gel electrophoresis experiments indicate that PPENBr-ONB exhibit excellent siRNA-loading capacity (1 mol PPENBr-ONB to more than 20 mol siRNA). Furthermore, PPENBr-ONB with large TPA cross-section (1.47 × 105 GM) exhibits promoted siRNA release (78%) under 720 nm illumination. In vitro experiment shows that PPENBr-ONB/siRNA complex could efficaciously knock out of targeted Plk1 mRNA to 24.7% under 720 nm illumination for 1 h. This two-photon excitation siRNA carrier offers an efficacious strategy for the exploitation of photo controlled gene delivery system.

A flexible and highly sensitive nonenzymatic glucose sensor based on DVD-laser scribed graphene substrate.

Flexible and implantable glucose biosensors are emerging technologies for continuous monitoring of blood-glucose of diabetes. Developing a flexible conductive substrates with high active surface area is critical for advancing the technology. Here, we successfully fabricate a flexible and highly sensitive nonenzymatic glucose by using DVD-laser scribed graphene (LSG) as a flexible conductively substrate. Copper nanoparticles (Cu-NPs) are electrodeposited as the catalyst. The LSG/Cu-NPs sensor demonstrates excellent catalytic activity toward glucose oxidation and exhibits a linear glucose detection range from 1 µM to 4.54 mM with high sensitivity (1.518 mA mM-1 cm-2) and low limit of detection (0.35 µM). Moreover, the LSG/Cu-NPs sensor shows excellent reproducibility and long-term stability. It is also highly selective toward glucose oxidation under the presence of various interfering species. Excellent flexing stability is also demonstrated by the LSG/Cu-NPs sensor, which is capable of maintaining 83.9% of its initial current after being bent against a 4-mm diameter rod for 180 times. The LSG/Cu-NPs sensor shows great potential for practical application as a nonenzymatic glucose biosensor. Meanwhile, the LSG conductive substrate provides a platform for the developing next-generation flexible and potentially implantable bioelectronics and biosensors.