Saturable absorption properties and ultrafast photonics applications of HfS3.

In this Letter, we focus on investigating the ultrafast photonics applications of two-layer HfS3 nanosheets. We prepared two-layer HfS3 nanosheets and carried out experiments to study their nonlinear saturable absorption properties. The results showed that the two-layer HfS3-based saturable absorber exhibited a modulation depth of 16.8%. Additionally, we conducted theoretical calculations using first principles to estimate the structural and electronic band properties of the two-layer HfS3 material. Furthermore, we utilized the two-layer HfS3 materials as SAs in an erbium-doped fiber cavity to generate mode-locked laser pulses. We measured a repetition frequency of 8.74 MHz, a pulse duration of 540 fs, and a signal-to-noise ratio of 77 dB. Overall, our findings demonstrate that the two-layer HfS3 material can serve as a reliable saturable absorber, possessing properties comparable to currently used two-dimensional materials. This expands the application fields of HfS3 materials and highlights their potential for advanced optoelectronic devices.

Optimal dose and type of exercise to improve depressive symptoms in older adults: a systematic review and network meta-analysis.

BACKGROUND: Depression is a prevalent issue among older adults, affecting their quality of life and overall well-being. Exercise is an effective means of relieving depressive symptoms in older adults, but the optimal dose for different exercise types remains unclear. As such, the aim of this meta-analysis was to examine the dose-response relationship between overall and specific types of exercise with depression symptoms in older adults. METHODS: This systematic review and network meta-analysis included a search of PubMed, Medline, Embase, PsycINFO, Cochrane library, and Web of Science for randomized controlled trials of exercise in older adults with depression symptoms from inception to 15 July 2023. Comprehensive data extraction covered dose, treatment regimen, demographics and study duration. Dosage metrics, encompassing METs-min/week, were scrutinized in correlation with the Minimal Clinically Importance Difference (MCID). RESULTS: A total of 47 studies involving 2895 participants and 7 kinds of exercise were included in the review. Without considering the dose, the results of our network meta-analysis indicated that Walking was the most effective in alleviating depression in older adults, in addition to Aerobic exercise (AE), Yoga, Qigong, Resistance training (RT), and Tai Chi (TC), which were equally effective. However, the results of the dose-response analysis found that Aerobic exercise was most effective at a dose of 1000 METs-min/week. It is noteworthy that Walking is significantly effective in alleviating depressive symptoms in older adults at very low doses. In terms of clinical benefits, we found that overall exercise doses in the range of 600 ~ 970 METs-min/week were clinically effective. Considering the specific types of exercise, Aerobic exercise, Resistance training, Walking, and Yoga were found to be effective at doses ranging from 820 ~ 1000 METs-min/week, 520 ~ 1000 METs-min/week, 650 ~ 1000 METs-min/week, 680 ~ 1000 METs-min/week, respectively. At the same time, we found that when the age exceeded 81 years, even when participating in exercise, it did not achieve the effect of alleviating depressive symptoms in older adults. CONCLUSIONS: In conclusion, including Walking, AE, Yoga, Qigong, RT, and TC, effectively alleviate depressive symptoms in older adults. Furthermore, we established statistically and clinically significant threshold doses for various exercise types. Early initiation of exercise is beneficial, but its efficacy diminishes from the age of 80, and beyond 81, exercise no longer significantly alleviates depressive symptoms.

Chromium oxide film for Q-switched and mode-locked pulse generation.

Chromium oxide (Cr2O3) is a promising material used in the applications such as photoelectrochemical devices, photocatalysis, magnetic random access memory, and gas sensors. But, its nonlinear optical characteristics and applications in ultrafast optics have not been studied yet. This study prepares a microfiber decorated with a Cr2O3 film via magnetron sputtering deposition and examines its nonlinear optical characteristics. The modulation depth and saturation intensity of this device are determined as 12.52% and 0.0176 MW/cm2. Meanwhile, the Cr2O3-microfiber is applied as a saturable absorber in an Er-doped fiber laser, and stable Q-switching and mode-locking laser pulses are successfully generated. In the Q-switched working state, the highest output power and shortest pulse width are measured as 12.8 mW and 1.385 µs, respectively. The pulse duration of this mode-locked fiber laser is as short as 334 fs, and its signal-to-noise ratio is 65 dB. As far as we know, this is the first illustration of using Cr2O3 in ultrafast photonics. The results confirm that Cr2O3 is a promising saturable absorber material and significantly extend the scope of saturable absorber materials for innovative fiber laser technologies.

Soliton interaction in a MXene-based mode-locked fiber laser.

MXenes are a class of two-dimensional layered structure ternary metal carbide or/and nitride materials. Recently, the MXene V2CTx has demonstrated excellent long-term stability, strong saturable absorption, and fast optical-switching capability, used to generate Q-switched and ultrashort pulsed lasers. However, bound-state fiber lasers based on V2CTx have not been reported yet. In this study, V2CTx is combined with a D-shaped fiber to form a saturable absorber device, whose modulation depth is measured to be 1.6%. By inserting the saturable absorber into an Er-doped fiber laser, bound states with different soliton separation and munbers are successfully obtained. Additionally, bound states with a compound soliton structure, such as the (2 + 2)- and (2 + 1)-type, are also realized. Our findings show that V2CTx can be developed as an efficient ultrafast photonics candidate to further understand the complex nonlinear dynamics of bound-state pulses in fiber lasers.

Chemiluminescence resonance energy transfer-based multistage nucleic acid amplification circuits for MiRNA detection with low background.

Chemiluminescence resonance energy transfer (CRET)-based assays have shown great potential in biosensing due to their negligible background autofluorescence, yet are still limited by their low sensitivity and short half-life luminescence. Herein, a multistage CRET-based DNA circuit was constructed with amplified luminescence signals for accurate miRNA detection and fixed reactive oxygen species (ROS) signals for cell imaging. The DNA circuit is designed through an ingenious programmable catalytic hairpin assembly (CHA), hybridization chain reaction (HCR), and the use of DNAzyme to realize target-triggered precise regulation of distance between the donor and acceptor for CRET-mediated excitation of photosensitizers. In detail, the analyte catalyzes the hybridization of CHA reactants, which leads to the assembly of multiple HCR-mediated DNAzyme nanowires. Subsequently, DNAzymes catalyze the oxidation of luminol by H2O2, and the adjacent photosensitizer chlorin e6 (Ce6) anchored on the DNA nanostructure is stimulated by the CRET process, resulting in the amplified long-wavelength luminescence and the generation of single oxygen signals through further energy transfer to oxygen. The biomarker miRNA can be detected with great sensitivity by integrating the recognition module into a universal platform. Furthermore, the DNA circuit enables CRET-mediated intracellular miRNA imaging, by detecting singlet oxygen signals through a ROS probe. The significant amplification effect is attributed to the robust multiple recognition of the target and the guaranteed transduction of the CRET signal through programmable engineering of DNA nanostructures. The CRET-based DNA circuit achieves amplified long-wavelength luminescence for accurate miRNA detection with low background and ROS-mediated signal fixation for cell imaging, making it a promising candidate for early diagnosis and theranostics.

Luminescence Color Tuning by Regulating Electrostatic Interaction in Light-Emitting Devices and Two-Photon Excited Information Decryption.

It is well-known that the variation of noncovalent interactions of luminophores, such as π-π interaction, metal-to-metal interaction, and hydrogen-bonding interaction, can regulate their emission colors. Electrostatic interaction is also an important noncovalent interaction. However, very few examples of luminescence color tuning induced by electrostatic interaction were reported. Herein, a series of Zn(II)-bis(terpyridine) complexes (Zn-AcO, Zn-BF4, Zn-ClO4, and Zn-PF6) containing different anionic counterions were reported, which exhibit counterion-dependent emission colors from green-yellow to orange-red (549 to 622 nm) in CH2Cl2 solution. More importantly, it was found that the excited states of these Zn(II) complexes can be regulated by changing the electrostatic interaction between Zn2+ and counterions. On the basis of this controllable excited state, white light emission has been achieved by a single molecule, and a white light-emitting device has been fabricated. Moreover, a novel type of data decryption system with Zn-PF6 as the optical recording medium has been developed by the two-photon excitation technique. Our results suggest that rationally controlled excited states of these Zn(II) complexes by regulating electrostatic interaction have promising applications in various optoelectronic fields, such as light-emitting devices, information recording, security protection, and so on.

Phosphorescent ion-paired iridium(III) complex for ratiometric and time-resolved luminescence imaging of intracellular biothiols.

A novel phosphorescent probe based on ion-paired iridium(III) complex has been designed and synthesized by incorporating α,ß-unsaturated ketone moiety in the cationic component. The phosphorescent intensity of cationic component is sensitive to bithiols, such as cysteine and homocysteine, based on the addition reaction of bithiols with α,ß-unsaturated ketone moiety, while that of the anionic component remains unchanged. Thus, this ion-paired iridium(III) complex can be used for ratiometric luminescence sensing and imaging of intracellular biothiols with excellent sensing performance. Moreover, the long phosphorescence lifetime of the cationic component is also sensitive to bithiols. Hence, this ion-paired iridium(III) complex has been further used for time-resolved luminescence imaging of intracellular biothiols. As far as we know, this is the first report about molecular probe for both ratiometric and time-resolved luminescence imaging of intracellular biothiols.

A Mitochondria-Targeted Photosensitizer Showing Improved Photodynamic Therapy Effects Under Hypoxia.

Organelle-targeted photosensitizers have been reported to be effective photodynamic therapy (PDT) agents. In this work, we designed and synthesized two iridium(III) complexes that specifically stain the mitochondria and lysosomes of living cells, respectively. Both complexes exhibited long-lived phosphorescence, which is sensitive to oxygen quenching. The photocytotoxicity of the complexes was evaluated under normoxic and hypoxic conditions. The results showed that HeLa cells treated with the mitochondria-targeted complex maintained a slower respiration rate, leading to a higher intracellular oxygen level under hypoxia. As a result, this complex exhibited an improved PDT effect compared to the lysosome-targeted complex, especially under hypoxia conditions, suggestive of a higher practicable potential of mitochondria-targeted PDT agents in cancer therapy.

Mitochondria-Directed Fluorescent Probe for the Detection of Hydrogen Peroxide near Mitochondrial DNA.

It is important to detect hydrogen peroxide (H2O2) near mitochondrial DNA (mtDNA) because mtDNA is more prone to oxidative attack than nuclear DNA (nDNA). In this study, a mitochondria-targeted fluorescence probe, pep3-NP1, has been designed and synthesized. The probe contains a DNA-binding peptide, a H2O2 fluorescence reporter, and a positively charged red emissive styryl dye to facilitate accumulation in mitochondria. Due to groove binding of the peptide with DNA, the styryl dye of pep3-NP1 intercalated into the bases of DNA, leading to an increase in red fluorescence intensity (centered at 646 nm) and quantum yield. In this case, pep3-NP1 was a turn-on probe for labeling DNA. Subcellular locations of pep3-NP1 and MitoTracker suggested that pep3-NP1 mostly accumulated in the mitochondria of live cells. Namely, as an intracellular DNA marker, pep3-NP1 bound to mtDNA. In the presence of H2O2, pep3-NP1 emitted green fluorescence (centered at 555 nm). Thus, the ratio of green with red fluorescence of pep3-NP1 was suitable to reflect the change of the H2O2 level near mtDNA in living cells. The detecting limit for H2O2 was estimated at 2.9 and 5.0 µM in vitro and in cultured cells, respectively. The development of pep3-NP1 could help in studies to protect mtDNA from oxidative stress.

A highly sensitive ratiometric fluorescent probe for the detection of cytoplasmic and nuclear hydrogen peroxide.

As a marker for oxidative stress and a second messenger in signal transduction, hydrogen peroxide (H2O2) plays an important role in living systems. It is thus critical to monitor the changes in H2O2 in cells and tissues. Here, we developed a highly sensitive and versatile ratiometric H2O2 fluorescent probe (NP1) based on 1,8-naphthalimide and boric acid ester. In response to H2O2, the ratio of its fluorescent intensities at 555 and 403 nm changed 1020-fold within 200 min. The detecting limit of NP1 toward H2O2 is estimated as 0.17 µM. It was capable of imaging endogenous H2O2 generated in live RAW 264.7 macrophages as a cellular inflammation response, and especially, it was able to detect H2O2 produced as a signaling molecule in A431 human epidermoid carcinoma cells through stimulation by epidermal growth factor. This probe contains an azide group and thus has the potential to be linked to various molecules via the click reaction. After binding to a Nuclear Localization Signal peptide, the peptide-based combination probe (pep-NP1) was successfully targeted to nuclei and was capable of ratiometrically detecting nuclear H2O2 in living cells. These results indicated that NP1 was a highly sensitive ratiometric H2O2 dye with promising biological applications.

Ultraflexible PEDOT:PSS/IrOx-Modified Electrodes: Applications in Behavioral Modulation and Neural Signal Recording in Mice.

Recent advancements in neural probe technology have become pivotal in both neuroscience research and the clinical management of neurological disorders. State-of-the-art developments have led to the advent of multichannel, high-density bidirectional neural interfaces that are adept at both recording and modulating neuronal activity within the central nervous system. Despite this progress, extant bidirectional probes designed for simultaneous recording and stimulation are beset with limitations, including elicitation of inflammatory responses and insufficient charge injection capacity. In this paper, we delineate the design and application of an innovative ultraflexible bidirectional neural probe engineered from polyimide. This probe is distinguished by its ability to facilitate high-resolution recordings and precise stimulation control in deep brain regions. Electrodes enhanced with a PEDOT:PSS/IrOx composite exhibit a substantial increase in charge storage capacity, escalating from 0.14 ± 0.01 mC/cm2 to an impressive 24.75 ± 0.18 mC/cm2. This augmentation significantly bolsters the electrodes' charge transfer efficacy. In tandem, we observed a notable reduction in electrode impedance, from 3.47 ± 1.77 MΩ to a mere 41.88 ± 4.04 kΩ, while the phase angle exhibited a positive shift from -72.61 ± 1.84° to -34.17 ± 0.42°. To substantiate the electrodes' functional prowess, we conducted in vivo experiments, where the probes were surgically implanted into the bilateral motor cortex of mice. These experiments involved the synchronous recording and meticulous analysis of neural signal fluctuations during stimulation and an assessment of the probes' proficiency in modulating directional turning behaviors in the subjects. The empirical evidence corroborates that targeted stimulation within the bilateral motor cortex of mice can modulate the intensity of neural signals in the stimulated locale, enabling the directional control of the mice's turning behavior to the contralateral side of the stimulation site.

Advanced nerve regeneration enabled by neural conformal electronic stimulators enhancing mitochondrial transport.

Addressing peripheral nerve defects remains a significant challenge in regenerative neurobiology. Autografts emerged as the gold-standard management, however, are hindered by limited availability and potential neuroma formation. Numerous recent studies report the potential of wireless electronic system for nerve defects repair. Unfortunately, few has met clinical needs for inadequate electrode precision, poor nerve entrapment and insufficient bioactivity of the matrix material. Herein, we present an advanced wireless electrical nerve stimulator, based on water-responsive self-curling silk membrane with excellent bioabsorbable and biocompatible properties. We constructed a unique bilayer structure with an oriented pre-stretched inner layer and a general silk membrane as outer layer. After wetting, the simultaneous contraction of inner layer and expansion of outer layer achieved controllable super-contraction from 2D flat surface to 3D structural reconfiguration. It enables shape-adaptive wrapping to cover around nerves, overcomes the technical obstacle of preparing electrodes on the inner wall of the conduit, and prevents electrode breakage caused by material expansion in water. The use of fork capacitor-like metal interface increases the contact points between the metal and the regenerating nerve, solving the challenge of inefficient and rough electrical stimulation methods in the past. Newly developed electronic stimulator is effective in restoring 10 mm rat sciatic nerve defects comparable to autologous grafts. The underlying mechanism involves that electric stimulation enhances anterograde mitochondrial transport to match energy demands. This newly introduced device thereby demonstrated the potential as a viable and efficacious alternative to autografts for enhancing peripheral nerve repair and functional recovery.

Tissue/Organ Adaptable Bioelectronic Silk-Based Implants.

Implantable bioelectronic devices, designed for both monitoring and modulating living organisms, require functional and biological adaptability. Pure silk is innovatively employed, which is known for its excellent biocompatibility, to engineer water-triggered, geometrically reconfigurable membranes, on which functions can be integrated by Micro Electro Mechanical System (MEMS) techniques and specially functionalized silk. These devices can undergo programmed shape deformations within 10 min once triggered by water, and thus establishing stable bioelectronic interfaces with natively fitted geometries. As a testament to the applicability of this approach, a twining peripheral nerve electrode is designed, fabricated, and rigorously tested, demonstrating its efficacy in nerve modulation while ensuring biocompatibility for successful implantation.

Rational design of an "OFF-ON" phosphorescent chemodosimeter based on an iridium(III) complex and its application for time-resolved luminescent detection and bioimaging of cysteine and homocysteine.

Biothiols, such as cysteine (Cys) and homocysteine (Hcy), play very crucial roles in biological systems. Abnormal levels of these biothiols are often associated with many types of diseases. Therefore, the detection of Cys (or Hcy) is of great importance. In this work, we have synthesized an excellent "OFF-ON" phosphorescent chemodosimeter 1 for sensing Cys and Hcy with high selectivity and naked-eye detection based on an Ir(III) complex containing a 2,4-dinitrobenzenesulfonyl (DNBS) group within its ligand. The "OFF-ON" phosphorescent response can be assigned to the electron-transfer process from Ir(III) center and C^N ligands to the DNBS group as the strong electron-acceptor, which can quench the phosphorescence of probe 1 completely. The DNBS group can be cleaved by thiols of Cys or Hcy, and both the (3)MLCT and (3)LC states are responsible for the excited-state properties of the reaction product of probe 1 and Cys (or Hcy). Thus, the phosphorescence is switched on. Based on these results, a general principle for designing "OFF-ON" phosphorescent chemodosimeters based on heavy-metal complexes has been provided. Importantly, utilizing the long emission-lifetime of phosphorescence signal, the time-resolved luminescent assay of 1 in sensing Cys was realized successfully, which can eliminate the interference from the short-lived background fluorescence and improve the signal-to-noise ratio. As far as we know, this is the first report about the time-resolved luminescent detection of biothiols. Finally, probe 1 has been used successfully for bioimaging the changes of Cys/Hcy concentration in living cells.

Genome-wide DNA methylation analysis reveals layer-specific methylation patterns in deer antler tissue.

This paper explored using of deer antlers as a model for studying rapid growth and cartilage formation in mammals. The genes and regulatory mechanisms involved in antler chondrogenesis are poorly understood, however, previous research has suggested that DNA methylation played a key role in antler regeneration. By using fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP), this study measured DNA methylation levels in cartilage (CA) and reserve mesenchyme (RM) cells and tissues. Results showed that RM cells (RMCs) DNA methylation levels were significantly lower than those of CA, suggesting that DNA demethylation may be involved in antler fast cartilage differentiation. The study also identified 20 methylated fragments specific to RMCs or CA using the methylation-sensitive amplified polymorphism (MSAP) technique and confirmed these findings using southern blot analysis. The data provide the first experimental evidence of a link between epigenetic regulation and rapid cartilage differentiation in antlers.

A mosquito mouthpart-like bionic neural probe.

Advancements in microscale electrode technology have revolutionized the field of neuroscience and clinical applications by offering high temporal and spatial resolution of recording and stimulation. Flexible neural probes, with their mechanical compliance to brain tissue, have been shown to be superior to rigid devices in terms of stability and longevity in chronic recordings. Shuttle devices are commonly used to assist flexible probe implantation; however, the protective membrane of the brain still makes penetration difficult. Hidden damage to brain vessels during implantation is a significant risk. Inspired by the anatomy of the mosquito mouthparts, we present a biomimetic neuroprobe system that integrates high-sensitivity sensors with a high-fidelity multichannel flexible electrode array. This customizable system achieves distributed and minimally invasive implantation across brain regions. Most importantly, the system's nonvisual monitoring capability provides an early warning detection for intracranial soft tissues, such as vessels, reducing the potential for injury during implantation. The neural probe system demonstrates exceptional sensitivity and adaptability to environmental stimuli, as well as outstanding performance in postoperative and chronic recordings. These findings suggest that our biomimetic neural-probe device offers promising potential for future applications in neuroscience and brain-machine interfaces. A mosquito mouthpart-like bionic neural probe consisting of a highly sensitive tactile sensor module, a flexible microelectrode array, and implanted modules that mimic the structure of mosquito mouthparts. The system enables distributed implantation of electrode arrays across multiple brain regions while making the implantation minimally invasive and avoiding additional dural removal. The tactile sensor array can monitor the implantation process to achieve early warning of vascular damage. The excellent postoperative short-term recording performance and long-term neural activity tracking ability demonstrate that the system is a promising tool in the field of brain-computer interfaces.

[Analysis on "the essence of tuina, arrival of qi ensuring curative effect"].

In reference with the systematic review of the thought of deqi (arrival of qi) put forward in Huangdi Neijing (Internal Classic of Yellow Emperor) and other classic books of traditional Chinese medicine, in view of detecting qi and identifying qi before treatment, as well as the prerequisites of deqi in tuina, meaning the accurate syndrome differentiation and manipulations, the importance of deqi in treatment with tuina is expounded. In association with clinical experience, the specific manifestations of deqi in patients during tuina are summarized, e.g. soreness, distention, pain, numbness, warm feeling and slight sweating, local changes in intestinal sound and skin color, as well as mind regulation. It is anticipated that deqi of tuina may be drawn the attention in clinical practice, and the relevant study be expanded.

Acid-improved DNAzyme-based chemiluminescence miRNA assay coupled with enzyme-free concatenated DNA circuit.

DNAzyme-based chemiluminescence assay exhibits excellent performance in bioanalysis but their operation in acid conditions remains challengeable. Herein, we constructed an acid-improved DNAzyme-based isothermal enzyme-free concatenated DNA circuit with significantly reduced background and simultaneously improved signal-to-noise ratio for miRNA detection. The chemiluminescence miRNA assay is composed of catalyzed hairpin assembly (CHA), hybridization chain reaction (HCR), and hemin/G-quadruplex DNAzyme units. The analyte initiates the self-assembly of CHA hairpins into numerous dsDNA, which triggers the subsequent autonomous cross-opening of HCR hairpins to generate long nanowires consisting of the hemin/G-quadruplex DNAzyme. The DNAzyme catalyzes the oxidation of luminol by hydrogen peroxide for the cascaded amplified chemiluminescence signal. The acid-improved property was demonstrated to be closely associated with the low catalytic activity of aggregated hemin under acidic conditions and the remained multiple amplified signal through concatenated DNA circuit. The general DNA circuit exhibited high sensitivity for miRNA-21 detection and chemiluminescence imaging under acidic conditions with a recognition hairpin. The acid-improved DNAzyme-based concatenated DNA circuit is promising to expand the application of chemiluminescence assay and provide a valuable strategy for early diagnosis and prognosis of cancer.

Utilization of Nonradiative Excited-State Dissipation for Promoted Phototheranostics Based on an AIE-Active Type I ROS Generator.

As for effective multimodal phototheranostic AIEgens, it is important to find strategies for manipulating photophysical dissipation to achieve optimized performance. Herein, a "all-in-one" phototheranostic AIEgen, (E)-3-(2-(2-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)vinyl)naphtho[1,2-d]thiazol-1-ium-1-yl)propane-1-sulfonate (NS-STPA) was constructed by a rigid coplanar grafting flexible rotor. NS-STPA nanoparticles (NPs) exhibited NIR fluorescent luminescence (FL) with φFL 2.78%. Upon 660 nm irradiation, the high photothermal conversion efficiency (39.01%) and effective reactive oxygen species (ROS) generation (5.28 times to Ce6) indicated the nonradiative decays are valuable in phototherapy. High •OH outputs showed NS-STPA NPs were outstanding type I ROS generators. The twisted D-A structure induced a large spin-orbit coupling (SOC), and insertion of thiophene decreased the S1-T1 energy gap (ΔEST). The nanoaggregate prolonged the triplet-state lifetime (τT). These all facilitate the intersystem crossing (ISC) for NS-STPA NPs. The photoinduced electron transfer resulted in •O2- and then •OH generation. In vivo evaluation indicated the promising application of NS-STPA NPs in FL and photothermal dual imaging-guided synergistic photodynamic and photothermal therapies.

A silk-based self-adaptive flexible opto-electro neural probe.

The combination of optogenetics and electrophysiological recording enables high-precision bidirectional interactions between neural interfaces and neural circuits, which provides a promising approach for the study of progressive neurophysiological phenomena. Opto-electrophysiological neural probes with sufficient flexibility and biocompatibility are desirable to match the low mechanical stiffness of brain tissue for chronic reliable performance. However, lack of rigidity poses challenges for the accurate implantation of flexible neural probes with less invasiveness. Herein, we report a hybrid probe (Silk-Optrode) consisting of a silk protein optical fiber and multiple flexible microelectrode arrays. The Silk-Optrode can be accurately inserted into the brain and perform synchronized optogenetic stimulation and multichannel recording in freely behaving animals. Silk plays an important role due to its high transparency, excellent biocompatibility, and mechanical controllability. Through the hydration of the silk optical fiber, the Silk-Optrode probe enables itself to actively adapt to the environment after implantation and reduce its own mechanical stiffness to implant into the brain with high fidelity while maintaining mechanical compliance with the surrounding tissue. The probes with 128 recording channels can detect high-yield well-isolated single units while performing intracranial light stimulation with low optical losses, surpassing previous work of a similar type. Two months of post-surgery results suggested that as-reported Silk-Optrode probes exhibit better implant-neural interfaces with less immunoreactive glial responses and tissue lesions. A silk optical fiber-based Silk-Optrode probe consisting of a natural silk optical fiber and a flexible micro/nano electrode array is reported. The multifunctional soft probe can modify its own Young's modulus through hydration to achieve accurate implantation into the brain. The low optical loss and single-unit recording abilities allow simultaneous optogenetic stimulation and multichannel readout, which expands the applications in the operation and parsing of neural circuits in behavioral animals.