Haitao Li

C-reactive protein (CRP), a key inflammatory biomarker, plays a critical role in clinical diagnostics; however, its reliable quantification demands analytical methods that surpass the limitations of conventional single-mode detection by integrating high sensitivity with built-in signal fidelity. Herein, we report a dual-mode photoelectrochemical (PEC) and colorimetric sensing platform based on bifunctional cobalt–ferrocene metal–organic framework (CoFcMOF) nanoflowers (NFs) for the ultrasensitive detection of CRP. The sensor is constructed on an In2O3-sensitized CdS heterojunction, which facilitates efficient charge separation and enhanced photocurrent response. The CoFcMOF NFs serve a dual function as both an antibody immobilization matrix and a peroxidase (POD)-mimicking signal transducer. Specific antigen–antibody recognition increases the interfacial electron-transfer resistance, leading to effective quenching of the PEC signal, while the POD-like activity of the CoFcMOF NFs catalyzes the oxidation of TMB, generating a distinct colorimetric readout. This integrated approach combines the advantages of intuitive visual screening and precise PEC quantification, addressing the inherent limitations of single-mode detection systems. The dual-mode platform enables simultaneous signal acquisition and achieves ultralow detection limits of 2.9 pg/mL (PEC) and 7.5 pg/mL (colorimetric) for CRP, which was also applied for CRP detection in serum and synovial fluid samples. This design offers significant synergistic advantages in functional integration, signal amplification, detection reliability, selectivity, and universal applicability, positioning it as a robust tool for the early diagnosis and disease monitoring in inflammatory arthritis and beyond. Beyond its analytical performance, this work introduces a versatile and robust paradigm for dual-mode biosensing and provides design principles for constructing multifunctional nanoarchitectures for next-generation sensing technologies.

Pyroptosis is an inflammatory programmed cell death process closely related to reactive oxygen species (ROS), in which hydrogen peroxide (H₂O₂) is considered to play a significant role. However, the specific stage at which H₂O₂ changes and whether it serves as the predominant ROS during pyroptosis remain unclear, hindering a deeper understanding of the underlying mechanism. In this study, a near-infrared fluorescence probe (DXM-CHO-B) with a high fluorescence quantum yield and large Stokes shift was obtained by molecular modification. DXM-CHO-B exhibited excellent specificity and high sensitivity to H₂O₂, featuring a wide linear range (50 nM-92 μM), a low detection limit (39 nM), and the ability to perform real-time H₂O₂ tracking in both cell and zebrafish models. DXM-CHO-B also maintained a high selectivity for H₂O₂ in cells, and the accuracy of the high selectivity was verified. Based on the excellent detection performance of DXM-CHO-B, the pyroptosis process of cells was monitored. The experimental results revealed that H₂O₂ was overexpressed during pyroptosis, and its amount undergoes significant changes in the early stage of pyroptosis. This conclusion was further supported by scanning electron microscopy imaging, lactate dehydrogenase release testing, and propidium iodide staining staining assays of pyroptosis cells at different time points. More importantly, further research has shown that the majority of ROS produced during pyroptosis were H₂O₂. These findings established H₂O₂ as the core mediator of pyroptosis, providing insights into its molecular mechanism and potential therapeutic strategies for enhancing tumor immunotherapy.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder in which oxidative stress plays a critical role in pathogenesis. As key reactive species governing oxidative stress, the dynamic interplay between glutathione (GSH) and hydrogen peroxide (H₂O₂) is tightly coupled to redox homeostasis. To enable simultaneous tracking of these two crucial species, we developed a dual-responsive fluorescent probe, TCS, for the discriminative visualization of GSH and H₂O₂. TCS features a methylsulfonyl group that is selectively reduced by GSH, triggering green fluorescence at 500 nm, and a boronate ester that is specifically cleaved by H₂O₂, generating red emission at 680 nm. These two optical channels operate independently with minimal spectral overlap, enabling simultaneous and discriminative detection of GSH and H₂O₂ without cross-interference. Probe TCS exhibits high sensitivity, excellent selectivity, and good photostability, and is well-suited for real-time imaging of both endogenous and exogenous GSH and H₂O₂ in complex biosystems. In okadaic acid-induced AD cell and zebrafish models, TCS revealed a time-dependent decrease in GSH levels accompanied by a concomitant increase in H₂O₂, consistent with progressive oxidative stress. Furthermore, comparative imaging of hippocampal tissues from AD model mice and wild-type mice showed markedly altered levels of both species, underscoring the utility of TCS for visualizing redox imbalance under AD-like pathological conditions. Collectively, this study establishes TCS as a powerful molecular tool for spatiotemporally resolved monitoring of GSH and H₂O₂ dynamics in living systems and provides a robust analytical platform for elucidating redox mechanisms in AD.

The interplay between gut microbiota and host plays a crucial role in human health and disease pathogenesis. However, current profiling methods for gut microbiota are costly, time-intensive and require specialized instrumentation. Herein, we develop a boronic acid-based sensor array, GUT-SCAN (Gut Unique Typing via Spectral and Chemical Analysis using Boronic Acid Nanosensor), for rapid profiling of human gut microbiota. The sensor array consists of six pH-responsive boronic acid derivatives and three pH environments (6.0, 7.4, and 8.2), forming an 18-channel sensor array. This array successfully distinguishes gut-derived bacteria with 100% accuracy. Additionally, it enables quantification of bacterial species associated with colorectal cancer (CRC) and identification of distinct bacterial compositions at varying mixing ratios. Notably, this sensor array is also capable of discriminating CRC at different stages. The simplicity, rapidity and affordability of this platform highlight its potential for microbiota analysis and its applicability in disease diagnostics, particularly for CRC.

Cell plasma membrane (PM) polarity and near-membrane hypochlorous acid (HClO) play crucial roles in cellular communication, signal transduction, and redox homeostasis. Their dysregulation is closely linked to many physiological and pathological processes. However, due to the lack of suitable probes, simultaneous detection of both PM polarity and near-membrane HClO has remained unachievable. To address this challenge, we developed the first PM-targetable dual-responsive fluorescence probe (DCVP-BF₂) for detecting these parameters via distinct emission channels. The probe exhibits a red (λ_em = 638 nm) fluorescence enhancement upon decreasing polarity and a green (λ_em = 506 nm) fluorescence "turn-on" response to HClO with high sensitivity and selectivity. DCVP-BF₂ features excellent photostability, low cytotoxicity, and an outstanding membrane-targeting ability. Using this probe, we revealed for the first time that there are concurrent increases in PM polarity and near-membrane HClO levels during cisplatin-induced apoptosis. Moreover, DCVP-BF₂ enabled discrimination between cancer and normal cells via simultaneous dual-analyte imaging and achieved clear visualization of tumor tissues in mouse models. Compared with single-analyte detection methods, this dual-detection probe offers a more accurate and reliable approach for investigating membrane polarity and HClO-associated apoptosis and tumor imaging, holding considerable potential for exploring the membrane-related pathophysiological processes that involve polarity and HClO alterations.

Acute kidney injury (AKI) is a critical clinical condition characterized by the rapid loss of renal function, requiring timely detection and intervention. Hydrogen sulfide (H₂S) and homocysteine (Hcy) have been identified as key biomarkers in AKI, yet their dynamic interplay and coordinated regulation remain elusive. Herein, we report a bifunctional fluorescent probe (Probe 1), based on coumarin derivatives, capable of real-time, simultaneous imaging of H₂S and Hcy in distinct fluorescence channels with high sensitivity, selectivity, and rapid response. Probe 1 enables the concurrent detection of H₂S and Hcy and was successfully applied to visualize both endogenous and exogenous levels in living cells. Notably, this probe achieved the first dual-channel imaging of H₂S and Hcy fluctuations in cisplatin-induced AKI models, both in vitro and in vivo. Furthermore, it was employed to evaluate therapeutic responses to AKI-related drug treatments, demonstrating its value for dynamic monitoring of disease progression and intervention efficacy. This study presents the first chemical tool for investigating the synergistic roles of H₂S and Hcy in AKI, offering new insights into sulfur-based signaling pathways and providing a promising platform for early diagnosis and therapeutic evaluation in AKI.

Angiogenesis is a critical driver of tumor metastasis, making it a key target for anticancer therapy. While oncogenic miR-21 has been identified as a key promoter of tumor angiogenesis through vascular endothelial growth factor (VEGF) regulation, existing approaches fail to visualize this epigenetic regulatory mechanism in real time. To address this gap, we developed two DNA tetrahedron sensors using DNA nanotechnology, enabling precise recognition and real-time visualization of miR-21 and its downstream VEGF mRNA through a dual-target synchronous detection strategy. Our results demonstrate that sensor 1 not only enables real-time imaging of miR-21-mediated angiogenesis in tumor cells but also exhibits robust antiangiogenic activity by specifically disrupting the miR-21/VEGF signaling pathway. This dual functionality effectively suppresses tumor cell migration and invasion. By integrating molecular diagnosis and therapeutic intervention, this strategy overcomes the limitations of conventional single-function sensors. It provides a novel tool for elucidating tumor angiogenesis mechanisms while highlighting the dual applications of DNA nanostructures in precision cancer therapy. This study opens new avenues for antimetastatic therapies based on epigenetic regulation and underscores the translational potential of functional DNA nanodevices in cancer treatment.

Fibroblast phenotypic transformation plays a crucial role in tumorigenesis. Tumor cell-derived exosome-mediated fibroblast phenotypic transformation has been commonly studied. However, there is still no direct evidence that the process of tumor cell-derived exosomes induces the transformation of fibroblasts into cancer-associated fibroblasts (CAFs). Herein, exosomal miRNAs were used as a target to track the invasion of cancer cell-derived exosomes into normal fibroblasts, and FAP mRNA, a CAF biomarker, further to trace the effect of exosomes on recipient cells. Two DNA tetrahedral sensors were developed based on a hybrid chain reaction signal amplification strategy and fluorescence resonance energy transfer mechanism. Both sensors showed high sensitivity and good selectivity, with detection limits of 4.94 and 6.61 pM for miR-1247-3p and FAP mRNA, respectively. Moreover, two sensors allowed us to image living cell postinvasion of tumor-derived exosomes, facilitating visual monitoring of fibroblast phenotype transformation and uncovering new perspectives on cancer metastasis development.