NIR Light Irradiation Research Articles

A Yb3+/Er3+ co-doped Bi1.95Yb0.04Er0.01V2O8 efficient upconversion glass–ceramic photocatalyst for antibiotic degradation driven by UV–Vis-NIR broad spectrum light

Photocatalytic films can be used to overcome the obstacles of nanoparticle agglomeration and powder recovery, but are limited by poor stability and low light utilization. Herein, a lanthanide-doped Bi1.95Yb0.04Er0.01V2O8 bulk upconversion glass–ceramic (GC) photocatalyst with a narrow bandgap was developed to overcome these limitations. Bi1.95Yb0.04Er0.01V2O8 was crystallized in the GC, and BiOCl nanosheets were in-situ grown on the surface of the bulk GC photocatalyst. The GC produced strong green (526 and 546 nm), and red (658 nm) emissions under 980 nm excitation. The absorption edge of the GC photocatalyst was extended to 620 nm, such that NIR photons were efficiently harvested, and most of the upconversion emissions during the photocatalysis process were utilized, a high norfloxacin degradation rate of 55.2% was obtained over 90 min of NIR light irradiation. The bulk GC photocatalyst can be easily regenerated by HCl etching again, and it is convenient for recovery. Furthermore, the photocatalyst is also suitable for practical treatment of wastewater with a low concentration of antibiotics, this study provides a novel strategy for the development of efficient photocatalytic films.

Upconversion nanoparticles coupled with hierarchical ZnIn2S4 nanorods as a near-infrared responsive photocatalyst for photocatalytic CO2 reduction

Developing near-infrared responsive (NIR) photocatalysts is very important for the development of solar-driven photocatalytic systems. Metal sulfide semiconductors have been extensively used as visible-light responsive photocatalysts for photocatalytic applications owing to their high chemical variety, narrow bandgap and suitable redox potentials, particularly the benchmark ZnIn2S4. However, their potential as NIR-responsive photocatalysts is yet to be reported. Herein, for the first time demonstrated that upconversion nanoparticles can be delicately coupled with hierarchical ZnIn2S4 nanorods (UCNPs/ZIS) to assemble a NIR-responsive composite photocatalyst, and as such composite is verified by ultraviolet–visible diffuse reflectance spectra and upconversion luminescence spectra. As a result, remarkable photocatalytic CO and CH4 production rates of 1500 and 220 nmol g−1h−1, respectively, were detected for the UCNPs/ZIS composite under NIR-light irradiation (λ ≥ 800 nm), which is rarely reported in the literature. The remarkable photocatalytic activity of the UCNPs/ZIS composite can be understood not only because the heterojunction between UCNPs and ZIS can promote the charge separation efficiency, but also the intimate interaction of UCNPs with hierarchical ZIS nanorods can enhance the energy transfer. This finding may open a new avenue to develop more NIR-responsive photocatalysts for various solar energy conversion applications.

CD29 targeted near-infrared photoimmunotherapy (NIR-PIT) in the treatment of a pigmented melanoma model

ABSTRACT Near-infrared photoimmunotherapy (NIR-PIT) is a newly developed cancer treatment that utilizes an antibody-photoabsorber-conjugate (AbPC) combined with NIR light. The AbPC is injected and binds to the tumor whereupon NIR light irradiation causes a photochemical reaction that selectively kills cancer cells. NIR-PIT is ideal for surface-located skin cancers such as melanoma. However, there is concern that the pigment in melanoma lesions could interfere with light delivery, rendering treatment ineffective. We investigated the efficacy of CD29- and CD44-targeted NIR-PIT (CD29-PIT and CD44-PIT, respectively) in the B16 melanoma model, which is highly pigmented. While CD29-PIT and CD44-PIT killed B16 cells in vitro and in vivo, CD29-PIT suppressed tumor growth more efficiently. Ki67 expression showed that cells surviving CD29-PIT were less proliferative, suggesting that CD29-PIT was selective for more proliferative cancer cells. CD29-PIT did not kill immune cells, whereas CD44-PIT killed both T and NK cells and most myeloid cells, including DCs, which could interfere with the immune response to NIR-PIT. The addition of anti-CTLA4 antibody immune checkpoint inhibitor (ICI) to CD29-PIT increased the infiltration of CD8 T cells and enhanced tumor suppression with prolonged survival. Such effects were less prominent when the anti-CTLA4 ICI was combined with CD44-PIT. The preservation of immune cells in the tumor microenvironment (TME) after CD29-PIT likely led to a better response when combined with anti-CTLA4 treatment. We conclude that NIR-PIT can be performed in pigmented melanomas and that CD29 is a promising target for NIR-PIT, which is amenable to combination therapy with other immunotherapies.

Synergistically boosting oxygen evolution performance of iron-tannic electrocatalyst via localized photothermal effect

Oxygen evolution electrocatalysis is temperature-dependent. The relatively high temperature is beneficial to improving the electrocatalytic performance. Integrating the photothermally induced thermal energy and the electrocatalytically active functionality into the bifunctional electrode is desirable for practical applications of energy-saving water splitting, but it is still challenging. Herein, we report the photothermally active Fe-tannic coordination network (Fe-Tan) nanoparticles covered on the oxidized iron foam (O-IF) show the remarkably boosted oxygen evolution electrocatalysis under irradiation of NIR laser. Benefiting from ligand-to-metal charge transfer between Fe3+ and tannic acid (TA), the Fe-Tan/O-IF electrode exhibits a broad absorption from UV to NIR region, which can rapidly generate effective heat-localization effect when exposed to NIR light irradiation. Bearing the coupled photothermal-electrocatalytic functionalities, the Fe-Tan/O-IF electrode irradiated by NIR light presents greatly enhanced performances and favorably improved kinetics in OER electrocatalysis processes compared with that under dark condition, which is superior to most of TA-based/derived OER electrocatalysts and compares favorably to many photothermal OER electrocatalysts previously reported.

A multifunctional nanoplatform delivering carbon monoxide and a cysteine protease inhibitor to mitochondria under NIR light shows enhanced synergistic anticancer efficacy.

Photoactivated chemotherapy has attracted widespread attention due to its ability to circumvent the shortcomings of hypoxia in tumor tissues compared with traditional photodynamic therapy. In this work, novel multifunctional nanoplatform (1), Ru-inhibitor@TPPMnCO@N-GQDs, was designed and prepared, which was capable of mitochondria-targeted co-delivery of the cysteine protease inhibitor and carbon monoxide (CO) stimulated with an 808 nm near infrared (NIR) laser. Nanoplatform (1) was prepared by covalent attachment of a mitochondria-targeted CO donor (TPPMnCO) and a Ru(II)-caged cysteine protease inhibitor (Ru-inhibitor) on the surface of fluorescent N-doped graphene quantum dots (N-GQDs). Nanoplatform (1) preferentially accumulated in the mitochondria of cancer cells and instantly delivered CO and the cysteine protease inhibitor upon 808 nm NIR light irradiation, thus damaging mitochondria and leading to significant in vitro and in vivo anticancer efficacy. In addition, nanoplatform (1) has good biocompatibility and did not exert any toxic side effects on mice during the period of treatment. The targeted subcellular mitochondrial co-delivery of CO and the cysteine protease inhibitor may provide new insights into CO and enzyme inhibitor combined therapies for cancer treatment.

Noble-metal-free plasmonic MoO3−x-based S-scheme heterojunction for photocatalytic dehydrogenation of benzyl alcohol to storable H2 fuel and benzaldehyde

Simultaneous generation of H2 fuel and value-added chemicals has attracted increasing attention since the photogenerated electrons and holes can be both employed to convert solar light into chemical energy. Herein, for realizing UV-visible-NIR light driven dehydrogenation of benzyl alcohol (BA) into benzaldehydes (BAD) and H2, a novel localized surface plasmon resonance (LSPR) enhanced S-scheme heterojunction was designed by combining noble-metal-free plasmon MoO3–x as oxidation semiconductor and Zn0.1Cd0.9S as reduction semiconductor. The photoredox system of Zn0.1Cd0.9S/MoO3–x displayed an unconventional reaction model, in which the BA served as both electron donor and acceptor. The S-scheme charge transfer mechanism induced by the formed internal electric field enhanced the redox ability of charge carriers thermodynamically and boosted charge separation kinetically. Moreover, due to the LSPR effect of MoO3−x nanosheets, Zn0.1Cd0.9S/MoO3−x photocatalysts exhibited strong absorption in the region of full solar spectrum. Therefore, the Zn0.1Cd0.9S/MoO3−x composite generated H2 and BAD simultaneously via selective oxidation of BA with high production (34.38 and 33.83 mmol·g−1 for H2 and BAD, respectively) upon full solar illumination. Even under NIR light irradiation, the H2 production rate could up to 94.5 mmol·g−1·h−1. In addition, the Zn0.1Cd0.9S/MoO3–x composite displayed effective photocatalytic H2 evolution rate up to 149.2 mmol·g−1·h−1 from water, which was approximate 6 times that of pure Zn0.1Cd0.9S. This work provides a reference for rational design of plasmonic S-scheme heterojunction photocatalysts for coproduction of high-value chemicals and solar fuel production.

Thermo-responsive polymer–black phosphorus nanocomposites for NIR-triggered bacterial capture and elimination

BP–PNIPAM can capture and eliminate bacteria under NIR light irradiation through hydrophilic-to-hydrophobic phase transition and hyperthermia.

Photobase-catalysed anionic thiol-epoxy click photopolymerization under NIR irradiation: from deep curing to shape memory

A photobase generator absorbing upconversion fluorescence can efficiently catalyze anionic thiol-epoxy click photopolymerization under 980 nm NIR light irradiation.

Green-/NIR-light-controlled rapid photochromism featuring reversible thermally activated delayed fluorescence and photoelectronic switching.

Fluorescent dithienylethene-based photochromic materials have been attracting considerable attention owing to their wide applications in biological and materials sciences. However, the limitations of detrimental UV irradiation for photocyclization, short emission lifetime, and inefficient photoresponsive speed still need to be addressed. Herein, a novel dithienylethene photochromic molecule, BFBDTE, has been prepared by the incorporation of a difluoroboron β-diketonate (BF2bdk) unit. The strong electron acceptor BF2bdk not only reduces the energy gap of the open isomer, ensuring visible light-controlled fluorescence switching, but also promotes intersystem crossing for the generation of thermally activated delayed fluorescence (TADF). Upon alternating irradiation with green and NIR light, BFBDTE presents a rare example of photochromism, fluorescence and TADF switching in various polar solvents and a poly(methyl methacrylate) (PMMA) film. Meanwhile, it shows rapid and well repeatable cyclization (12 s) and cycloreversion reactions (20 s) in PMMA, accompanied by fast TADF switching within 11 s. Furthermore, photo-electrochemical measurements reveal a remarkable on-off photoelectronic response (photocurrent density ratio: Ilight/Idark = 684) between the open- and closed-form of BFBDTE. These remarkable merits make BFBDTE promising for photoswitchable molecular devices, optical memory storage systems, NIR detectors, and photoelectric switching.

Silk Microneedle Patch Capable of On‐Demand Multidrug Delivery to the Brain for Glioblastoma Treatment (Adv. Mater. 1/2022)

Tumor Therapy In article number 2106606, Nan Qin, Tiger H. Tao, and co-workers report a heterogenous silk microneedle patch to spatiotemporally and sequentially deliver multiple therapeutic drugs for hemostasis, anti-angiogenesis, and apoptosis of brain tumor cells. Drug release kinetics are well-defined by tuning the crosslinking degree of the silk and applying a trigger of transcranial NIR-light irradiation. This biodegradable patch has potential applications for the clinical treatment of intracranial tumors.

Sandwich-structured MXene@Au/polydopamine nanosheets with excellent photothermal-enhancing catalytic activity

Local surface plasmon resonance (LSPR) of noble metal nanoparticles plays a significant role in nanocatalysis via directly harvesting optical energy from resonant light. However, the photothermally-assistant catalytic application is limited due to the narrow visible/infrared absorption range and low photothermal conversion efficiency. Herein, a sandwich-structured MXene@Au/Polydopamine (PDA) nanosheet with good hydrophilicity, large specific surface area and tri-photothermal components is developed for nanocatalysis. The Au/PDA hybrid shells are covered on the MXene nanosheets via a simple one-step redox-oxidize polymerization method. As a result, the catalytic dynamic of MXene@Au/PDA nanosheets on reducing 4-nitrophenol reaches to 0.28 min−1·mg−1, which is about 2 times larger than that of the nanocatalysts without NIR light irradiation. Owing to the well protection of PDA shell, after 10 cycles of reduction of 4-nitrophenol, MXene@Au/PDA nanosheets still maintain more than 90% activity. This work in depth insights into NIR light-assistant avenue to enhance the catalytic activity of noble metal nanocatalysts and highlights an easy synthetic model for heterogeneous catalysts based on MXene nanocomposites.

Lipoprotein-biomimetic nanostructure enables tumor-targeted penetration delivery for enhanced photo-gene therapy towards glioma

Glioma is one of the most malignant primary tumors affecting the brain. The efficacy of therapeutics for glioma is seriously compromised by the restriction of blood-brain barrier (BBB), interstitial tumor pressure of resistance to chemotherapy/radiation, and the inevitable damage to normal brain tissues. Inspired by the natural structure and properties of high-density lipoprotein (HDL), a tumor-penetrating lipoprotein was prepared by the fusion tLyP-1 to apolipoprotein A-I-mimicking peptides (D4F), together with indocyanine green (ICG) incorporation and lipophilic small interfering RNA targeted HIF-1α (siHIF) surface anchor for site-specific photo-gene therapy. tLyP-1 peptide is fused to HDL-surface to facilitate BBB permeability, tumor-homing capacity and -site accumulation of photosensitizer and siRNA. Upon NIR light irradiation, ICG not only served as real-time targeted imaging agent, but also provided toxic reactive oxygen species and local hyperthermia for glioma phototherapy. The HIF‐1α siRNA in this nanoplatform downregulated the hypoxia‐induced HIF‐1α level in tumor microenvironment and enhanced the photodynamic therapy against glioma. These studies demonstrated that the nanoparticles could not only efficiently across BBB and carry the payloads to orthotopic glioma, but also modulate tumor microenvironment, thereby inhibiting tumor growth with biosafety. Overall, this study develops a new multifunctional drug delivery system for glioma theranostic, providing deeper insights into orthotopic brain tumor imaging and treatment.

Visible-NIR light-responsive 0D/2D CQDs/Sb2WO6 nanosheets with enhanced photocatalytic degradation performance of RhB: Unveiling the dual roles of CQDs and mechanism study

Environmental pollution caused by dye wastewater discharge has attracted much attention in the past decades. Developing photocatalysts with high solar energy utilization efficiency for the treatment of dye wastewater is one of the most promising methods to address afore-mentioned environmental problem. Herein, novel Vis-NIR (visible to near-infrared) light-responsive carbon quantum dots modified Sb2WO6 (CQDs/Sb2WO6) nanosheets with remarkably enhanced photocatalytic degradation performance of Rhodamine B (RhB) aqueous solution were successfully synthesized. Under the irradiation of Vis light, the photocatalytic degradation efficiency reaches 83% over the optimal composite, which is nearly seven times higher than that of pristine Sb2WO6. Meanwhile, under NIR light irradiation, the optimal composite also keeps a stable degradation performance, while pristine Sb2WO6 exhibits sluggish performance. Besides, a detailed photocatalytic degradation pathway was proposed via the analyses of corresponding intermediates in the photocatalytic degradation process. On the basis of electron spin resonance spectrometry, quenching experiment and density functional theory (DFT) calculation, hydroxyl radicals (•OH) play a dominating role in the photocatalytic reactions and a possible photocatalytic degradation mechanism was unearthed. This work provides new insights for constructing novel Vis-NIR responsive photocatalysts to purify dye wastewater for environmental remediation.

Achieving NIR Light-Mediated Tumor-Specific Fenton Reaction-Assisted Oncotherapy by Using Magnetic Nanoclusters.

As an emerging strategy for oncotherapy, Fenton chemistry can efficiently improve the conversion from endogenous H2O2 into highly toxic ·OH in the whole high-performance therapeutic process. Although promising, the efficiency of Fenton reaction in tumor regions is highly limited by the inefficient delivery of Fenton reagents and the restrictive conditions of tumor microenvironment. One promising strategy against the above limitations is to specifically increase the temperature around the tumor regions. In this study, a novel NIR light-mediated tumor-specific nanoplatform based on magnetic iron oxide nanoclusters (MNCs) was rationally designed and well developed for photothermally enhanced Fenton reaction-assisted oncotherapy. MNCs could accumulate into the tumor regions with the help of an external magnet field to enable T2-weighted magnetic resonance (MR) imaging of tumors and MR imaging-guided combined antitumor therapy. Our well-prepared MNCs also revealed excellent photothermal effect upon a NIR light irradiation, promising their further important role as a photothermal therapy (PTT) agent. More importantly, heat induced by the PTT of MNCs could accelerate the release of Fe from MNCs and enhance the efficiency of Fenton reaction under H2O2-enriched acidic tumor microenvironment. Results based on long-term toxicity investigations demonstrated the overall safety of MNCs after intravenous injection. This work therefore introduced a novel nanoplatform based on MNCs that exerted a great antitumor effect via photothermally enhanced tumor-specific Fenton chemistry.

Cu-mediated NIR photoinduced polymerization for highly sensitive electrochemical nucleic acid detection

An original electrochemical biosensor via Cu-mediated near-infrared light (NIR) polymerization was reported for highly sensitive nucleic acid detection. Lung cancer DNA as nucleic acid model was specifically recognized via phosphate-free peptide nucleic acid (PNA). Subsequently, initiators of polymerization were attached to PNA/DNA heteroduplex under the assistance of phosphate-Zr4+-carboxylate. Cu2(OH)PO4 and H2O2 system was triggered off under the irradiation of NIR light, and then hydroxyl radicals (•OH) were produced. At the same time, carbon-based radicals were also generated through the reaction between •OH and methacrylic monomers of polymerization, which initiated the photoinduced polymerization. Then, numerous ferrocene-based methacrylic monomers were modified on the surface of electrode. The limit of detection was improved to 2.6 fM with linear range from 0.01 pM to 1000 pM (R2 = 0.993), and the minimum molar number of lung cancer DNA was 26 zmol (in 10 μL). This biosensor also presented portable and cost-efficient feature due to simple operation and ubiquitous light, and no phototoxicity and good tissue penetration of NIR also endowed this strategy great potential in biological detection.

Hybrid thermoresponsive nanoparticles containing drug nanocrystals for NIR-triggered remote release

The on-demand administration of anaesthetic drugs can be a promising alternative for chronic pain management. To further improve the efficacy of drug delivery vectors, high drug loadings combined with a spatiotemporal control on the release can not only relief the pain according to patient’s needs, but also improve the drawbacks of conventional burst release delivery systems. In this study, a hybrid nanomaterial was developed by loading bupivacaine nanocrystals (BNCs) into oligo(ethylene glycol) methyl ether methacrylate (OEGMA)-based thermoresponsive nanogels and coupling them to NIR-absorbing biodegradable copper sulphide nanoparticles (CuS NPs). Those CuS NPs were surface modified with polyelectrolytes using layer-by-layer techniques to be efficiently attached to the surface of nanogels by means of supramolecular interactions. The encapsulation of bupivacaine in the form of nanocrystals allowed to achieve CuS@BNC-nanogels having drug loadings as high as 65.5 wt%. The nanocrystals acted as long-lasting drug reservoirs, leading to an elevated localized drug content, which was useful for their application in prolonged pain relief. The CuS@BNC-nanogels exhibited favorable photothermal transducing properties upon NIR-light irradiation. The photothermal effect granted by the CuS NPs triggered the nano-crystallized drug release to be boosted by the collapse of the thermoresponsive nanogels upon heating. Remote control was achieved for on-demand release at a specific time and place, indicating their potential use as an externally activated triggerable drug-delivery system. Furthermore, cell viability tests and flow cytometry analysis were performed showing satisfactory cytocompatibility in the dose-ranging study having a subcytotoxic concentration of 0.05 mg/mL for CuS@BNC-nanogels. This remotely activated nanoplatform is a promising strategy for long-lasting controlled analgesia and a potential alternative for clinical pain management.

Ratiometric Fluorescence Imaging of Intracellular MicroRNA with NIR-Assisted Signal Amplification by a Ru-SiO2@Polydopamine Nanoplatform.

Accurate and sensitive fluorescence imaging of intracellular miRNA is essential for understanding the mechanism underlying some physiological and pathological events, as well as the prevention and diagnosis of diseases. Herein, a highly sensitive ratiometric fluorescent nanoprobe for intracellular miRNA imaging was fabricated by integrating a Ru-SiO2@polydopamine (Ru-SiO2@PDA) nanoplatform with a near-infrared light (NIR)-assisted DNA strand displacement signal amplification strategy. The Ru-SiO2@PDA spheres have excellent biosafety, high photothermal effect, and unique photophysical properties that can both emit a stable red fluorescence and well quench the fluorophores getting closer to them. So, when the fuel DNA and carboxyfluorescein (FAM)-labeled signal DNA are co-assembled on their outer surfaces, the FAM's green fluorescence is quenched, and a low ratiometric signal is obtained. However, in the presence of miRNA, the target displaces the signal DNA from the capture DNA, releasing the signal DNA far away from the Ru-SiO2@PDA. Then, the green fluorescence recovers and leads to an enhanced Igreen/Ired value. Under NIR light irradiation, the Ru-SiO2@PDA increases the local temperature around the probe and triggers the release of fuel DNA, which thus recycles the target miRNA and effectively amplifies the ratiometric signal. Using A549 cells as a model, the nanoprobe realizes the highly sensitive ratiometric fluorescence imaging of miRNA let-7a, as well as its in vivo up- and down-regulation expressions. It provides a facile tool for highly sensitive and accurate intracellular miRNA detection through one-step incubation and may pave a new avenue for single-cell analysis.

Photocatalytic H2O2 production and removal of Cr (VI) via a novel Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure with broad spectral response

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.

Green Carbon Dots (GCDs) for Photocatalytic Hydrogen Evolution and Antibacterial Applications

AbstractMicrowave technique was used to synthesize Green Carbon Dots (GCDs) from Aloe vera leaves because of easy to apply, accessible, time‐saving, cheap, safe and environmental‐friendly way. The prepared GCDs/TiO2 composite was obtained via sensitization of TiO2 with the help of GCDs. The characterization of the GCDs/TiO2 was made optically, structurally and morphologically. The photocatalytic hydrogen activity of GCDs/TiO2 was investigated under visible light (λ>420 nm) irradiation in the aqueous solution using triethanolamine (TEOA) sacrificial electron donor. When Pt was used, GCDs/TiO2/Pt showed advanced hydrogen evolution production (1294 μmol g−1 h−1) approximately two‐fold compared to GCDs/TiO2 (718 μmol g−1 h−1). In addition, NIR light‐triggered antibacterial activity of GCDs on Gram‐negative Escherichia coli (E. coli) and Gram‐positive Staphylococcus aureus (S. aureus) were investigated by studying bacterial growth curve and abiotic GSH oxidation assay. GSH oxidation ability of GCDs was increased through NIR light irradiation. According to the bacterial growth curve test, E. coli was found to be more susceptible to our GCDs than S. aureus.

Alloyed AuPt nanoframes loaded on h-BN nanosheets as an ingenious ultrasensitive near-infrared photoelectrochemical biosensor for accurate monitoring glucose in human tears

Photo-electro-chemical (PEC) glucose biosensor has recently attracted extensive attention due to the double advantages of both photocatalysis via photon energy utilization and electrocatalytic oxidation through extra electric field. Compared with previous shorter wavelength (violet-visible) light-induced PEC reaction, the anticipated near infrared (NIR, >~700 nm) excited PEC biosensor with multiple fascinating features should be more suitable for clinical diagnostic biology. Herein, we report an ingenious NIR-PEC biosensor by loading alloyed Au5Pt9 nanoframes on two dimensional (2D) hexagonal boron nitride (h-BN) nanosheets. The obtained h-BN/Au5Pt9 nanoframes exhibit a remarkable higher NIR-PEC activity in comparison with other as-prepared h-BN/AuPt references. The improved PEC performance is attributed to the enhanced synergetic coupling effect between Au5Pt9 nanoalloys and constitutionally stable h-BN that gives rise to a stronger absorbance capacity and pronounced localized surface plasmon resonance (LSPR) in visible-NIR region as well as high free-electron mobility of framework-like Au/Pt. Interestingly, the obtained h-BN/Au5Pt9 nanoframes excited by 808 nm NIR light provide superior PEC accuracy and sensitivity as compared to visible or other NIR light irradiation. Then, the novel 808 nm NIR-PEC biosensor was used for precise glucose monitoring in human tears with a detectable concentration of 0.03~100 μM and a low detection limit of 0.406 nM. Undoubtedly, the proposed h-BN/Au5Pt9 nanoframes as an appealing NIR-PEC glucose biosensor can possess greater potential values for practical glucose monitoring in biomedicine.