Nitric oxide is an endogenous biological signaling molecule, and the corresponding fractional exhaled NO serves as an important indicator in clinical diagnostics and therapeutic applications. However, achieving accurate and rapid monitoring of ppb-level fractional exhaled nitric oxide (FeNO) at room temperature remains a significant challenge. Herein, ultrathin porphyrin metal–organic framework (MOF) sheets are selected to assemble with supramolecularly functionalized graphene sheets through hydrogen bonding and electrostatic interaction with 6 nm thickness. The resulting porphyrin MOF/graphene sheet-on-sheet nanohybrid is designed as a chemiresistive NO sensor which exhibits superior gas sensing performance at room temperature including an ultralow practical limit of detection (Ra/Rg = 1.047, 5 ppb NO), reliable repeatability, excellent selectivity against other exhaled gases, and relative long-term stability. Mechanism study indicates that the prominent NO sensing performance is attributed to the ordered framework of active sites of ferric-pyrrole (Fe─N4) sites and less than 10 nm thick sheet-on-sheet heterojunction structure in the nanohybrid. The potential clinical utility of the obtained sensors is validated by exhalation tests toward exhalation samples from healthy individuals and asthma patients, respectively. This work provides an effective strategy of developing MOF-based room temperature ppb-level chemiresistive NO sensors for practical FeNO monitoring.@en

The development of materials toward ppb-level nitric oxide (NO) sensing at room temperature remains in high demand for the monitoring of respiratory inflammatory diseases. In order to find an iron-containing molecule without steric hindrance to combine with graphene for room temperature NO gas sensing, here a supramolecular assembly of ferrocene (Fc) and reduced graphene oxide (rGO) was designed and prepared for NO sensing. The assembly of Fc/rGO was characterized using FT-IR, TEM, and XPS measurements. The Fc/rGO-based sensors exhibited superior NO sensing properties at room temperature including high response (R_a/R_g = 1.73, 1 ppm), high selectivity against other exhaled gases, reliable repeatability and stability (less than 4 % decrease after 40 days). A practical limit of detection (LOD) of 200 ppb was achieved. The theoretical simulation demonstrates that ferrocene is assembled via π-π interaction with rGO in edge-to-face configuration which provides relatively lower energy than face-to-face configuration does for the whole assembly. It was first verified that the enhanced adsorption capacity and the charge transfer between NO and Fc/rGO would result in improvement of the assembly's sensitivity toward NO after ferrocene was assembled with graphene. This work provides a fresh approach of anchoring iron on graphene for gas sensing via supramolecular methods.

@en

The significant in situ multicolored patterning without changing printing tools nor substrate media still remains challenging, especially toward practical applications for anti-counterfeiting. This research invented a unique universal approach for the laser-induced in situ synthesis of colorful fluorescent patterns (from blue: CIE 0.15, 0.18 to red orange: CIE 0.36, 0.39) through the controlled formation of N, S doped carbon dots (CDs) in solid composite polymer films or hydrogel with a hierarchical and physically unclonable microsurface architecture for anti-counterfeiting. The in situ patterning approach, coupled with multi-layer technique, yielding designable blue, yellow, orange, and red orange color under 365 nm in the same pattern. A 5 cm² colorful pattern can be efficiently finished within 5 min without changing the substrate and the line width accuracy can be up to 300 μm. The absolute quantum efficiency of the blue pattern reached as high as 23%. The fluorescent patterns can be survived at indoor for 24 months. The hydrogen bonding interactions between the CDs precursor and polymer facilitated the generation, uniform dispersion and stabilization of CDs during the laser irradiation. The hypothesis that laser irradiation induced photochemical reactions of CD precursors within a polymer matrix was supported by thermodynamic assessments. The universality of in situ fluorescent patterning strategy was demonstrated by developing fluorescent patterns on both solid polymer films, hydrogel, pharmaceutical packaging and textile.

@en

This study introduces a novel strategy for fabricating flexible nitrogen dioxide (NO₂) gas sensors based on Indium Oxide (In₂O₃) nanoparticles (NPs) employing selective reduction laser sintering (SRLS) technology. The SRSL technology utilizes ultraviolet (UV) laser selective reduction sintering to precisely and rapidly create oxygen vacancy (OV) defects in In₂O₃ NPs. These oxygen vacancies (OVs) enhance the active adsorption sites and contribute additional free electrons, significantly improving sensor performance at room temperature. The sensors demonstrate excellent response (S = 460.9 at 10 ppm), rapid response/recovery times (τ_resp/τ_reco = 27/570 s), and superior selectivity (response ratio > 400), in addition to robust resistance to light and humidity (under ppm-level NO₂ gas). The sensors also exhibit a low detection limit (200 ppb), a high signal-to-noise ratio (94.8 dB), and good long-term stability (25 days). Moreover, under photo-assisted conditions, the recovery speed of the sensors is further improved. This technology not only provides an innovative strategy for the development of high-performance flexible NO₂ gas sensors but also broadens the application potential of laser direct writing (LDW) technology in advanced materials and sensor fabrications.

@en

A new type of carbonized polymer dot was prepared by the one-step hydrothermal method of triethoxylsilane (TEOS) and citric acid (CA). The sensor made from carbonized polymer dots (CPDs) showed superior gas sensing performance toward ammonia at room temperature. The Si, O-codoped CPDs exhibited superior ammonia sensing performance at room temperature, including a low practical limit of detection (pLOD) of 1 ppm (Ra/Rg: 1.10, 1 ppm), short response/recovery time (30/36 s, 1 ppm), high humidity resistance (less than 5% undulation when changing relative humidity to 80 from 30%), high stability (less than 5% initial response undulation after 120 days), reliable repeatability, and high selectivity against other interferential gases. The gas sensing mechanism was investigated through control experiments and in situ FTIR, indicating that Si, O-codoping essentially improves the electron transfer capability of CPDs and synergistically dominates the superior ammonia sensing properties of the CPDs. This work presents a facile strategy for constructing novel high-performance, single-component carbonized polymer dots for gas sensing.@en

This study introduces an innovative approach for fabricating flexible nitrogen dioxide (NO₂) gas sensors based on In2O3 nanoparticles (NPs) using selective reduction laser sintering (SRLS) technology. The SRLS technology enables specific chemical reduction reactions during the sintering process, achieving fabrication and control of oxygen vacancy defects and the porous structure in the In₂O₃ sintering region. The sensor exhibits exceptionally high sensitivity, fast response/recovery times, and superior selectivity for NO₂ gas detection, particularly at room temperature. Compared with traditional NO₂ gas sensor fabrication methods, this technology not only provides a potential way to fabricate highperformance NO₂ gas sensors but also further expands the application potential of laser direct writing (LDW) technology in the fields of advanced materials and sensor fabrication.

@en

This study presents an AlN based Lamb wave (A0 mode) liquid sensing device that can be used for biomedical applications. The Lamb wave device features a 1.5 μm composite membrane consisting of a 500 nm LPCVD SiN and a 1 μm of a c-axis oriented AlN film. A 45° rotated design was also considered for this project to reduce the reflections from the edges towards the output IDT. A liquid testing experiment involving IPA, DI water, and D-PBS was performed to see if the devices were able to differentiate between these liquids. The results showed that the fabricated Lamb wave devices exhibited sensitivity to mass loading and were able to distinguish between the liquids based on their phase, frequency, and gain characteristics. Notably, devices with the rotated design have shown a substantial increase in resonance by 15 dB, as well as enhanced sensitivity, when compared to the devices with the normal design. Furthermore, the devices featuring the normal design had a Q factor of 450, whereas devices with the rotated design exhibited a Q factor of 680, indicating superior performance of the latter. These findings suggest that a Lamb wave device with the 45° rotated IDT design holds considerable potential for liquid sensing, particularly in biomedical applications.

@en

Fractional exhaled nitric oxide (FeNO) can be used to describe inflammatory processes in the respiratory tract. Directly detecting ppb-level nitric oxide (NO) with chemiresistive sensors at room temperature faces the challenges of simultaneously obtaining high sensitivity and high stability for sensors. We aimed to improve the stability and sensitivity of NO sensors. We assembled sheet-like porphyrin-based MOF DLS-2D-Co-TCPP(Fe) with 5-aminonaphthalene-1-sulfonic acid-rGO (ANS-rGO) nanosheets through coordination interactions. In this way, we offered a room-temperature NO-sensing hybrid, DLS-2D-Co-TCPP(Fe)/ANS-rGO, with a sheet-on-sheet (SOS) architectural heterojunction. The DLS-2D-Co-TCPP(Fe)/ANS-rGO-based sensor demonstrated superior NO-sensing performance, including high sensitivity (R_a/R_g = 1.33, 250 ppb), reliable repeatability, high selectivity, and fast response/recovery (150 s/185 s, 1 ppm) at a sensing concentration from 100 ppb to 10 ppm at room temperature. The obtained sensor showed high stability, retaining >85% of its initial response after 60 days. Designing NO-responsive Fe-N₄ active units containing MOF nanosheets, along with constructing a heterojunction with an SOS architecture to facilitate carrier migration, collaboratively dominated the superior performance of synthesized NO sensors. This work provides a strategy for designing SOS architectural heterojunctions to obtain high-performance MOF-based gas-sensing materials.

@en

This study introduces a high-performance flexible temperature sensor prepared using laser-induced graphene (LIG) doped with nickel oxide (NiO) nanoparticles (NPs). Unlike conventional LIG surface doping methods, we developed a nickel oxide-doped LIG flexible temperature sensor by introducing NiO NPs into a polyimide (PI) precursor solution cured into a film followed by ultraviolet (UV) laser treatment. This approach achieves a more stable and uniform doping process while further improving the sensing performance of LIG-based temperature sensors. Over a prospective temperature detection range (30-100 °C), the sensitivity of the NiO-doped LIG temperature sensor is significantly improved from -0.064% °C-¹ to -0.079% °C-¹, an improvement of 19.3%, compared to that of the intrinsic LIG temperature sensor, while maintaining high linearity (R2 = 0.999) as well as excellent temperature stability and reliability. This research not only enhances the performance of flexible temperature sensors based on LIG but also paves new pathways for its industrial production in various application fields.

@en

In recent years, flexible strain sensors based on metal cracks have garnered significant interest for their exceptional sensitivity. However, striking a balance between sensitivity and detection range remains a significant challenge, which often limits its wider application. Herein, we introduce an innovative laser transmission pyrolysis technology to fabricate high-performance flexible strain sensors based on (Au) metal cracks with a microchannel array on the PDMS surface. The fabricated flexible strain sensors exhibit high sensitivity, wide detection range, precise strain resolution, fast response and recovery times, and robust durability. Furthermore, this technology has potential applications in microfluidics, microelectromechanical systems, and optical sensing.@en

Inspired by the activation mechanism of slow anion channels 1 (SLAC1) in plants that proton pump reversibly induces plant stomata open for CO2 adsorption, a CO2-switching H+ conduction/HCO3− diffusion dual ion channel (CO2-switching-DIC) was constructed by assembling γ-cyclodextrin-MOF (γ-CD-MOF) and 3,4,9,10-perylenetetracarboxylic acid (PTCA) for CO2 chemiresistive sensing. The obtained CO2 sensor exhibited high response (Rg/R0 = 1.33, 50 ppm) and selectivity, low practical limit of detection (1 ppm) and excellent consistency (94.5%) with a commercial infrared CO2 meter at room temperature. It is indicated that hydrogen bond networks in CO2-switching-DIC will be enlarged with the increasing of carboxylic group’s content on perylene skeleton, thereby modulating proton conductivity at molecular level and furthermore CO2 sensing performance of the composite. The CO2-switching-DIC-based sensor has been utilized to distinguish the exhaled CO2 concentration between lung cancer patients and healthy individuals, illustrating its promising application prospect in non-invasive diagnose.@en

In this study, a convenient chitosan oligosaccharide laser lithograph (COSLL) technology was developed to fabricate laser-induced graphene (LIG) electrodes and flexible on-chip microsupercapacitors (MSCs). With a simple one-step CO₂ laser, the pyrolysis of a chitosan oligosaccharide (COS) and in situ welding of the generated LIGs to engineering plastic substrates are achieved simultaneously. The resulting LIG products display a hierarchical porous architecture, excellent electrical conductivity (6.3 Ω sq^-1), and superhydrophilic properties, making them ideal electrode materials for MSCs. The pyrolysis-welding coupled mechanism is deeply discussed through cross-sectional analyses and finite element simulations. The MSCs prepared by COSLL exhibit considerable areal capacitance of over 4 mF cm^-2, which is comparable to that of the polyimide-LIG-based counterpart. COSLL is also compatible with complementary metal-oxide-semiconductor (CMOS) and micro-electro-mechanical system (MEMS) processes, enabling the fabrication of LIG/Au MSCs with comparable areal capacitance and lower internal resistance. Furthermore, the as-prepared MSCs demonstrate excellent mechanical robustness, long-cycle capability, and ease of series-parallel integration, benefiting their practical application in various scenarios. With the use of eco-friendly biomass carbon source and convenient process flowchart, the COSLL emerges as an attractive method for the fabrication of flexible LIG on-chip MSCs and various other advanced LIG devices.

@en

This research introduces a novel and convenient technology, chitosan oligosaccharide laser lithography (COSLL), enabling the creation of flexible laser-induced graphene (LIG) on-chip microsupercapacitors (MSCs) using environmentally friendly chitosan-class polymers for the first time. MSCs prepared through COSLL exhibit a significant areal capacitance exceeding 4 mF cm^-2, comparable to that of the polyimide-LIG-based counterparts. COSLL seamlessly integrates with the micro-nano thin-film process, allowing the capacitance of resulting LIG/Au MSCs to be further increased to about 8 mF cm^-2. Leveraging an eco-friendly biomass carbon source and featuring a convenient process flowchart, COSLL emerges as an appealing method for fabricating flexible LIG on-chip MSCs.

@en

To develop multifunctional small-molecule prodrugs is highly desirable for cancer treatment but remains challenging in intrinsic traceability. As an acid-cleavable linkage, a Schiff bases benefiting from its distinctive fluorescence quenching ability was selected to prepare a small-molecule prodrug with cancer-targeted and self-indicating. In this study, we designed and developed a multifunctional self-assembled nanobomb of amphiphilic TPE-Lenalidomide prodrug, which comprises a hydrophobic aggregation-induced emission (AIE) probe 4-(1,2,2-triphenylvinyl)benzaldehyde (TPE-CHO) and a hydrophilic anticancer drug Lenalidomide via a Schiff base linkage. We investigated the synergistic effect of d-PET and C═N isomerization which would keep the fluorescence of TPE-Lenalidomide in the “always off” state by density functional theory (DFT) calculation. Once reaching the pathological site, such a vesicular nanobomb of TPE-Lenalidomide will be acidolyzed to release the AIE probe and Lenalidomide molecules simultaneously, consequently realizing high-efficiency effects of tumor imaging and cancer therapy (cell viability: normal cell L929, ∼79.49%; cancer cell 4T1, ∼27.08%; p = 0.000118). This work may pave an avenue to prepare small-molecule prodrugs for tumor-targeted diagnosis and cancer therapy.

@en

Acoustics has high variety of applications ranging from structural-health monitoring, sonar, and biological applications to sensors. The acoustic domain employs pressure waves for detection and provides better performance for sensing applications that require interactions with mechanical signals. High-performance sensing is possible by using acoustic biosensors in biological applications since most of the biological signals are in mechanical domain, in which the sensing mechanism directly interacts with them. In this chapter, the physics for different acoustic modes are introduced and their specific applications are mentioned, as well as sensing principles and operating mechanisms are presented. Also, the structural perspectives for acoustic biosensors are given and the fabrication techniques and materials are described. In this chapter, the biochemical principles behind the sensing are introduced and the layers and surfaces interacting with biomolecules are discussed. Some of the commercially available acoustic biosensors are presented and a short discussion of future perspectives is given.

@en

In this article, the avalanche withstand capability and transient failure model of commercial 1200 V asymmetric trench gate SiC MOSFETs are investigated by experiment and simulation under single-pulse unclamped inductive switching (UIS) conditions. The limiting avalanche current and limiting avalanche energy of the device are determined by evaluating the voltage and current waveforms, the power dissipation, and the avalanche energy curves before and during avalanche failure. Then, by using the calibrated simulation model, the sequence between the critical electric field stress and critical thermal stress suffered by the device is revealed, and the transient failure mode of the device is proved to be the thermal runaway. Moreover, after decapping the failed device, the failure mode of the device is further confirmed by analyzing the failure point. Finally, by using the focused ion beam (FIB) technology, the failure mechanism of the device is confirmed as a structural rupture caused by avalanche thermal stress.@en

In recent years, metal crack-based stretchable flexible strain sensors have attracted significant attention in wearable device applications due to their extremely high sensitivity. However, the tradeoff between sensitivity and detection range has been an intractable dilemma, severely limiting their practical applications. Herein, we propose a laser transmission pyrolysis (LTP) technology for fabricating high-performance flexible strain sensors based on (Au) metal cracks with the microchannel array on the polydimethylsiloxane (PDMS) surface. The fabricated flexible strain sensors exhibit high sensitivity [gauge factor (GF) of 2448], wide detection range (59% for tensile strain), precise strain resolution (0.1%), fast response and recovery times (69 and 141 ms), and robust durability (over 3000 cycles). In addition, experiment and simulation results reveal that introducing a microchannel array enables the stress redistribution strategy on the sensor surface, which significantly improves the sensing sensitivity compared to conventional flat surface sensors. Based on the excellent performance, the sensors are applied to detect subtle physiological signals, such as pulse and swallowing, as well as to monitor large-scale motion signals, such as knee flexion and finger bending, demonstrating their potential applications in health monitoring, human-machine interactions, and electronic skin.

@en

BACKGROUND: Accurate characterization of glioma is crucial for clinical decision making. A delineation of the tumor is also desirable in the initial decision stages but is time-consuming. Previously, deep learning methods have been developed that can either non-invasively predict the genetic or histological features of glioma, or that can automatically delineate the tumor, but not both tasks at the same time. Here, we present our method that can predict the molecular subtype and grade, while simultaneously providing a delineation of the tumor. METHODS: We developed a single multi-task convolutional neural network that uses the full 3D, structural, preoperative MRI scans to predict the IDH mutation status, the 1p/19q co-deletion status, and the grade of a tumor, while simultaneously segmenting the tumor. We trained our method using a patient cohort containing 1508 glioma patients from 16 institutes. We tested our method on an independent dataset of 240 patients from 13 different institutes. RESULTS: In the independent test set, we achieved an IDH-AUC of 0.90, an 1p/19q co-deletion AUC of 0.85, and a grade AUC of 0.81 (grade II/III/IV). For the tumor delineation, we achieved a mean whole tumor Dice score of 0.84. CONCLUSIONS: We developed a method that non-invasively predicts multiple, clinically relevant features of glioma. Evaluation in an independent dataset shows that the method achieves a high performance and that it generalizes well to the broader clinical population. This first-of-its-kind method opens the door to more generalizable, instead of hyper-specialized, AI methods.

@en

The fabrication of flexible pressure sensors with low cost, high scalability, and easy fabrication is an essential driving force in developing flexible electronics, especially for high-performance sensors that require precise surface microstructures. However, optimizing complex fabrication processes and expensive microfabrication methods remains a significant challenge. In this study, we introduce a laser pyrolysis direct writing technology that enables rapid and efficient fabrication of high-performance flexible pressure sensors with a micro-truncated pyramid array. The pressure sensor demonstrates exceptional sensitivities, with the values of 3132.0, 322.5, and 27.8 kPa^-1 in the pressure ranges of 0-0.5, 0.5-3.5, and 3.5-10 kPa, respectively. Furthermore, the sensor exhibits rapid response times (loading: 22 ms, unloading: 18 ms) and exceptional reliability, enduring over 3000 pressure loading and unloading cycles. Moreover, the pressure sensor can be easily integrated into a sensor array for spatial pressure distribution detection. The laser pyrolysis direct writing technology introduced in this study presents a highly efficient and promising approach to designing and fabricating high-performance flexible pressure sensors utilizing micro-structured polymer substrates.

@en

A better understanding of transcriptional evolution of IDH-wild-type glioblastoma may be crucial for treatment optimization. Here, we perform RNA sequencing (RNA-seq) (n = 322 test, n = 245 validation) on paired primary-recurrent glioblastoma resections of patients treated with the current standard of care. Transcriptional subtypes form an interconnected continuum in a two-dimensional space. Recurrent tumors show preferential mesenchymal progression. Over time, hallmark glioblastoma genes are not significantly altered. Instead, tumor purity decreases over time and is accompanied by co-increases in neuron and oligodendrocyte marker genes and, independently, tumor-associated macrophages. A decrease is observed in endothelial marker genes. These composition changes are confirmed by single-cell RNA-seq and immunohistochemistry. An extracellular matrix-associated gene set increases at recurrence and bulk, single-cell RNA, and immunohistochemistry indicate it is expressed mainly by pericytes. This signature is associated with significantly worse survival at recurrence. Our data demonstrate that glioblastomas evolve mainly by microenvironment (re-)organization rather than molecular evolution of tumor cells.

@en