Acute pancreatitis (AP) is a common digestive system disease with severe symptoms. Its causes are diverse, including drug induced pancreatitis (DIP) on the rise in recent years. Antibiotic drugs such as tetracycline, which induced AP has received considerable attention. Tetracycline disrupts pancreatic cell apoptosis, proliferation and activate inflammatory signaling pathways. Chymotrypsin (CHT) is the main digestive protease in the pancreas and is crucial for the development of pancreatitis. Thus, there is an urgent need to develop a practical and efficient approach for real-time tracking of CHT secretion from pancreatic cells under drug-induced pancreatitis (DIP) conditions. To address this challenge, we report the rational design and synthesis of a near-infrared fluorescent probe, termed HNTC-DIP, for highly accurate monitoring of CHT dynamics in a tetracycline-induced pancreatitis model. The probe rapidly detects CHT within 5 min through enzymatic cleavage of its ester bonds, which restores the intramolecular charge transfer (ICT) process. The fluorescence intensity shows a 14-15-fold enhancement. In addition, it has been utilized effectively to bioimage and evaluate endogenous CHT variations in DIP models (tetracycline-induced pancreatitis model). HNTC-DIP can serve as a reliable and suitable tool for accurately visualizing DIP damage for the first time and these applications also demonstrate the potential in the risk assessment of clinical application for antibiotic drugs.

Monitoring pulmonary injury caused by environmental exposures remains a critical challenge in toxicological and diagnostic research. Herein, we report a near-infrared (NIR) fluorescent probe, DDAO-B, designed for the real-time and noninvasive imaging of butyrylcholinesterase (BChE) activity—a key enzyme involved in inflammatory regulation and xenobiotic detoxification. The probe operates via an intramolecular charge transfer (ICT)-mediated fluorescence “turn-on” mechanism, achieving a 260-fold emission enhancement at 674 nm upon enzymatic activation, with a detection limit of 0.041 U/L and excellent photostability. DDAO-B enabled precise visualization of BChE distribution in lung epithelial cells and revealed its upregulation during lipopolysaccharide (LPS)-induced pulmonary inflammation. More importantly, the probe was successfully applied to smoke exposure mouse models, where dynamic fluorescence imaging demonstrated dose- and duration-dependent accumulation of pulmonary toxicity. Fluorescent signal intensity strongly correlated with cigarette concentration and exposure time, with specific enrichment in lung tissue confirmed by organ imaging and histopathological analysis. These findings underscore the potential of DDAO-B as a versatile diagnostic tool for assessing environmental hazards and investigating the mechanisms of lung injury.

β-Glucuronidase (GUS) is an acidic hydrolase enzyme overexpressed in various inflammatory diseases, making it a promising biomarker for inflammation. However, current tools for real-time, in situ imaging of GUS activity are hindered by background interference, which reduces their effectiveness in dynamic biological environments. To address this challenge, we developed Ox-GUS, a GUS-specific fluorescent probe with a unique molecular design featuring a disrupted conjugated structure. This design provided Ox-GUS with near-zero background optical properties, a significantly enhanced signal-to-noise ratio, and a highly sensitive detection ability. The probe demonstrated a fluorescence enhancement of up to 400 folds in response to GUS activity, with a detection limit as low as 0.0035 U/mL. We successfully employed Ox-GUS to visualize GUS activity in real-time in mouse models of rheumatoid arthritis, autoimmune hepatitis, and inflammatory bowel disease, and effectively monitored therapeutic responses. This study highlights the potential of Ox-GUS as a robust tool for advancing research on GUS-related inflammatory mechanisms and for early diagnosis and treatment monitoring of inflammatory diseases.

The mechanical force exerted by dermal fibroblasts is crucial for promoting cutaneous tissue regeneration and wound healing. However, the implantation of a force interface in vivo or within tissue has become a new challenge in measuring mechanical force. Here, we report a microneedle patch with DNA tension gauge tethers (ME-TGT patch) to monitor the mechanical force of dermal fibroblasts in mice. Microneedles served as the force and electrode interface. When the integrin of the fibroblast membrane is successfully recognized by the integrin ligand (cRGDfk) in the tension probe, the duplex splits irreversibly by cellular mechanical force. The conformation rearrangement driven by a mechanical force can be converted into electrochemical signals. The ME-TGT patch can be used for verification of approximately 12 piconewtons (pN) of mechanical force exerted by fibroblasts in vitro and in vivo. Moreover, we used the ME-TGT patch to monitor cell mechanics during wound healing in skin tissue and found fluctuation (rising first and then falling in the process of 0-14 days) in mice. The ME-TGT patch allowed for monitoring mechanical force on fibroblasts in vivo and provided a novel tool for further research into mechanical mechanisms in tissue regeneration.

Colitis is considered a significant risk factor for the development and progression of colorectal cancer due to excessive inflammation formed as a result of inflammatory bowel disease (IBD), which is linked to colorectal cancer development. Colorectal cancer often lacks overt symptoms in its early stages, leading to late-stage diagnosis in most patients. Therefore, timely diagnosis and differentiation of colitis and colorectal cancer are crucial. This study introduces a novel activatable carboxylesterase 2 (CES2) fluorescent probe, DBF-CES2, consisting of a cationic indolium fluorophore and a CES2-specific benzyl ester recognition group. The probe operates via the intramolecular charge transfer (ICT) mechanism. Upon binding and hydrolysis by CES2, a potent electron- donating hydroxyl group is released, enhancing the ICT effect and increasing fluorescence intensity, emitting red fluorescence light (lambda em = 680 nm). The probe had a large Stokes shift of 167 nm and a detection limit as low as 0.70 ng/mL. It also had high selectivity, sensitivity, and biocompatibility. Cellular imaging experiments demonstrated that CES2 expression levels in colorectal cancer cells were higher than those in normal cells. The DBF-CES2 probe specifically recognized endogenous CES2 in colorectal cancer cells, promptly distinguishing them from normal cells. In vivo imaging in mice confirmed that the probe could differentiate between colitis and colorectal cancer, allowing for the assessment of the therapeutic effects of two drugs. The synthesized CES2targeting organic small molecule fluorescent probe DBF-CES2 is a new molecular tool for the early diagnosis of colitis and colorectal cancer-related diseases, holding significant potential in clinical diagnostics.

Fluorescent probes play a vital role in biological detection and imaging; however, their application is often hampered by high background fluorescence, which compromises detection sensitivity and reduces the signal-to-noise ratio. Oxazine 1 is a modifiable near-infrared fluorophore that can be used to develop low-background probes. Nonetheless, it suffers from limitations such as insufficient red-shifted emission, low fluorescence quantum yield, and poor cellular uptake. To address these limitations, we designed and synthesized two new oxazine derivatives, JSO and JDO, by replacing the diethylamino donor group of oxazine 1 with a rigid julolidine moiety. This structural modification effectively enhanced electron-donating ability, suppressed nonradiative decay, and improved membrane permeability. Compared to oxazine 1, the emission wavelength of JDO was red-shifted (703 nm), and its fluorescence quantum yield increased 2-fold. JDO also had superior intracellular accumulation and excellent pH stability and photostability. By leveraging these advantages, we developed a novel peroxynitrite (ONOO-)-responsive probe, JDO-ONOO, as a proof-of-concept demonstration to validate the design platform. Through strategic disruption of the fluorophore's conjugated structure, JDO-ONOO emitted ultralow background fluorescence, and in the presence of ONOO-, the fluorescence switched to a "turn-on" mode, resulting in a 130-fold increase in intensity. The probe had high sensitivity (LOD = 3.7 nM), rapid response, and excellent selectivity under physiological conditions. It was successfully employed in the fluorescence imaging of ONOO- in living cells and in multiple mouse models of inflammation. Overall, this study presents a universal strategy for developing next-generation low-background fluorescent probes, demonstrated through ONOO- detection.

Pancreatic diseases are closely linked with the abnormal activity of various proteases, including chymotrypsin. Currently, probes specifically designed for the detection of chymotrypsin in pancreatic disorders are unavailable. In this study, we developed a highly specific and sensitive fluorescent probe for the detection of chymotrypsin activity to enable precise diagnosis of pancreatic diseases. The probe was incorporated with Nile red as the fluorescent moiety and 4-bromobutanoyl as the recognition and quenching group to facilitate a "fluorescence switch" response upon enzymatic cleavage. The probe had high specificity and sensitivity to chymotrypsin, which remained unaffected in the presence of 52 biological interferents. It had a linear detection range of 0.1-0.75 mu g/ mL and a limit of detection of 0.0203 mu g/mL, indicative of superior analytical performance. Cellular assays showed that the probe could effectively distinguish between normal pancreatic cells and tumor cells. Furthermore, the applications of the probe in pancreatitis models revealed its capability to accurately differentiate between normal tissue, chronic pancreatitis, and acute pancreatitis and to provide robust support for real-time imaging and disease progression monitoring. Subsequent in vivo experiments further validated the probe's diagnostic efficacy, highlighting its potential in the diagnosis of pancreatic diseases. These findings provide a solid foundation for developing molecular tools for early diagnosis and therapeutic monitoring of pancreatic disorders, demonstrating its significant potential in clinical diagnostics and precision medicine.

Early diagnosis of rheumatoid arthritis (RA) is essential for preventing disease progression and improving prognosis. This study proposes the use of carbon monoxide (CO) as a potential biomarker for RA. Two fluorophores, HM-OH and DHM-OH, were designed and synthesized, using DHM-OH due to its superior spectroscopic properties. The combination of DHM-OH with allyl bromide produced the fluorescent probe DHM-CO, which had a large Stokes shift (302 nm) and a long emission wavelength (882 nm). DHM-CO enabled metal-free catalytic detection of CO. The probe was demonstrated to have excellent water solubility, photostability, and high sensitivity to CO; therefore, it could selectively respond to CO without interference from other substances. The limit of detection of the probe in the detection of CORM-3, a CO precursor, was as low as 0.027 mu M. DHM-CO was successfully used for the imaging of endogenous and exogenous CO in A549 cells. It was also successful in the tracking of CO in RA models, revealing that the CO concentrations in RA joints were significantly higher compared to that in normal joints. Additionally, the therapeutic effect of methotrexate (MTX) on RA was verified. This study introduces the first imaging of CO in RA, offering a valuable tool for early diagnosis and treatment of RA.

Atherosclerosis (AS) is a common disease associated with cholesterol metabolism. Cholesterol esterase (CHE), which is found primarily in the liver, intestines, adipose tissue, and skin, plays a crucial role in cholesterol metabolism; thus, it is a potential biomarker for the early diagnosis and therapeutic monitoring of AS. Traditional fluorescent probes for detecting AS often rely on general biomarkers such as reactive oxygen species (ROS) or proteases, which lack specificity. To address this limitation, we developed a novel CHE-responsive fluorescent probe, NR-CHE, which utilizes cholic acid as the recognition group. This probe was synthesized by an esterification reaction between cholic acid and a lipid droplet-targeting near-infrared dye, NR-OH. The NR-CHE probe integrated the lipid droplet-targeting capability of NR with the specific response of CHE, thus offering a unique affinity for cells with lipid abnormalities and enabling precise imaging of atherosclerosis. In vitro experiments demonstrated that NR-CHE exhibited superior optical properties, with a detection limit of 0.076U/mL. Tests involving 32 common biological interferents confirmed that the recognition group cholic acid provided high selectivity to the probe. Cell experiments further validated that NR-CHE is an effective tool for monitoring endogenous CHE in live cells. Comprehensive fluorescence imaging assessments in an AS mouse model showed that NR-CHE delivered exceptional imaging accuracy. As an extended application, NR-CHE also demonstrated potential in image-guided surgical resection in a liver cancer model. Collectively, NR-CHE holds great promise as a tool for the accurate diagnosis of AS and for guiding tumor resection surgery.

The aggressive nature and high mortality rate of lung cancer underscore the imperative need for early diagnosis of the disease. Thus, aminopeptidase N (APN), a potential biomarker for lung cancer, should be thoroughly investigated in this context. This report describes the development of HA-apn, a novel near-infrared fluorescent probe, specifically engineered for the sensitive detection of endogenous APN. Characterized by its high selectivity, straightforward molecular architecture, and suitable optical properties, including a long-wavelength emission at 835 nm and a large Stokes shift of 285 nm, HA-apn had high efficacy in identifying overexpressed APN in tumor cells, which shows its potential in pinpointing malignancies. To further validate its applicability and effectiveness in facilitating the direct and enhanced visualization of pulmonary alterations, an in situ lung cancer mouse model was employed. Notably, HA-apn was applied for in vivo imaging of APN activity in the lung cancer mouse model receiving the probe through aerosol inhalation, and rapid and precise diagnostic results were achieved within 30 min post-administration. Overall, HA-apn can be applied as an effective, non-intrusive tool for the rapid and accurate detection of pulmonary conditions.

Autoimmune thyroid diseases (AITD) often interfere with early detection due to asymptomatic symptoms and normal thyroid function in routine tests. Developing early diagnostic tools is crucial for timely and accurate treatment, potentially reducing complications and improving patient outcomes. In this study, we developed Ox- NE, a novel fluorescent probe designed for the specific detection and quantification of neutrophil elastase (NE), a key biomarker of inflammation. Unlike the traditional probes, Ox-NE utilizes a unique mechanism that minimizes background fluorescence and enhances photostability, offering rapid, non-invasive, and apparent diagnostic capabilities. Ox-NE had a low limit of detection (LOD) of 1.54 mu g/mL and exhibited high sensitivity and specificity with strong anti-interference properties. Through in vitro experiments, Ox-NE could accurately detect elevated NE levels in the serum of thyroiditis patients. Additionally, it could differentiate between normal thyroid cells, inflamed thyroid cells, and thyroid cancer cells. It also effectively facilitated the screening of sivelestat, a therapeutic agent for thyroiditis. Successful fluorescence imaging in mouse models further confirmed the potential of Ox-NE in advancing thyroid disease diagnostics.

Vanin-1 is a pantetheine hydrolase that plays a key role in inflammatory diseases. Effective tools for noninvasive, real-time monitoring of Vanin-1 are lacking, largely due to background fluorescence interference in existing probes. To address this issue, we developed a dual-modal fluorescent and colorimetric probe, MB-Van1, to detect Vanin-1 with high sensitivity and selectivity. MB-Van1 has a structure optimized to exhibit nearly zero background fluorescence, resulting in a high signal-to-noise ratio that enables the accurate detection of Vanin-1 activity in various biological tissues. In vitro experiments demonstrated that MB-Van1 had a detection limit as low as 0.031 ng/mL in the fluorescence mode. We successfully employ MB-Van1 to observe elevated Vanin-1 levels in inflammatory tissues of various mouse models of rheumatoid arthritis (RA), drug-induced liver injury (DILI), and nonsteroidal anti-inflammatory drug (NSAID) enteropathy models, within only 5 min. This advancement provides a novel approach for monitoring the dynamic changes of Vanin-1 during inflammation, offering new strategies for the early diagnosis and therapeutic assessment of other related diseases.

At present, surgical resection is the primary clinical treatment method for pancreatic cancer. Accurate assessment of resectability is crucial for effective treatment planning. This paper focuses on the detection of carbohydrate antigen 125 (CA125), the in vitro biomarker for determining the resectability of pancreatic cancer. We prepared a highly stable electrochemiluminescence (ECL) luminophore, Zn-PTC, by coordinating perylene tetracarboxylic acid (PTCA) with Zn2+ ions. However, the current applications of Zn-PTC as ECL luminophores face challenges due to their high luminescence potential. To address these challenges, we introduced the ECL resonance energy transfer (ECL-RET) strategy and synthesized a composite material, BNCs@Zn-PTC, to achieve low-potential anodic ECL luminescence. In the ECL-RET system, Zn-PTC serves as the energy donor, while gold-silver bimetallic nanoclusters (Au-Ag BNCs) act as the energy acceptor. UV-Vis spectra of Au-Ag BNCs partially overlapped with the ECL spectra of Zn-PTC, which facilitate to effective ECL-RET between the donor and the acceptor. Utilizing BNCs@Zn-PTC as ECL luminophores, we constructed a strand displacement reaction-catalyzed hairpin assembly (SDR-CHA) dual in vitro amplified ECL sensor to detect the target CA125. Under optimal experimental conditions, the sensor had a linear detection range at CA125 concentration from 1 mu U mL- 1 to 10 U mL- 1, with a detection limit of 0.24 mu U mL- 1. This study presents a novel approach for developing low-potential ECL-emitting luminophores with significant potential in clinical applications.

Non-alcoholic fatty liver disease (NAFLD) now affects more than one quarter of the global population and becomes a heavy public health burden. However, the underlying mechanism for the pathogenesis of NAFLD is still not clear. Carboxylesterase 2 (CES2), highly abundant in the liver and intestine, plays an important role in endogenous lipid metabolism and lipolysis. So far, the literatures for the role of CES2 in the development of NAFLD are still limited. In this study, we designed and synthesized a near-infrared fluorescent probe (HP-LZ-CES2) which can be specifically recognized and hydrolyzed by CES2, releasing a benzoate residue and a fluorophore (HP-LZ) with good fluorescence signal. With this probe, CES2 levels can be quantitatively measured in vitro and qualitatively visualized in living cells and mice. The probe has the advantages of large Stokes shift, high detection sensitivity and good selectivity. Further, the CES2 expression levels were visually investigated in both high-fat cells as the in vitro model for NAFLD and high-fat diet fed mouse as the in vivo model for NAFLD. The cell imaging experiments indicated a reduction of fluorescence signal in high-fat hepatic cells. The in vivo experiments showed an obvious reduction of fluorescence in the liver of NAFLD mouse model, which is consistent with the hepatic cell experiments. In contrast, an enhancement of fluorescence was observed in the intestine of NAFLD mouse model. As a result, the NAFLD mouse model can be visually distinguished from the normal chow mouse by vision. Therefore, the proposed probe can be an auxiliary tool for the diagnosis of NAFLD and a visual tool for understanding CES2’s role in the development of NAFLD.

Microplastic pollution, particularly from polystyrene (PS), poses increasing risks to human health due to its persistence in the environment, tendency to bioaccumulate, and ability to induce oxidative stress and hepatic injury. However, tools for dynamic imaging that elucidate the mechanistic link between microplastic exposure and liver toxicity remain lacking. Herein, we report a far-red fluorescent probe (emission maximum at 674 nm), DDAO-CT, derived from the hydroxyl-substituted red-emitting fluorophore DDAO (9,9-dimethylacridin-2(9H)-one derivative), designed for in vivo visualization of chymotrypsin activity, a key enzyme marker known to be upregulated during microplastic-induced liver damage. DDAO-CT is constructed by conjugating a 4-bromobutyryl recognition group to the red-emissive fluorophore DDAO, which quenches fluorescence by disrupting intramolecular charge transfer (ICT). Upon enzymatic hydrolysis by chymotrypsin, the ICT pathway is restored, resulting in a 14-fold enhancement in fluorescence at 674 nm with a detection limit of 3.5 ng/mL. The probe had high selectivity, low cytotoxicity, and excellent responsiveness to enzyme activity both in vitro and in PS-exposed hepatocytes. Notably, in vivo imaging in mouse models revealed dose-dependent fluorescence signals in the liver, which correlated closely with histopathological damage and elevated serum markers of liver injury. These results show that chymotrypsin activation is a downstream event of PS bioaccumulation, establishing DDAO-CT as an effective tool for visualizing pollutant-induced hepatic dysfunction. This study presents a novel chemical biology platform for noninvasive assessment of environmental hepatotoxins and offers mechanistic insights into microplastic-induced liver injury at the enzymatic level.

Breast cancer is a major global health concern that necessitates early diagnosis and effective monitoring of therapeutic efficacy. beta-galactosidase (beta-gal) is a valuable biomarker linked to cellular senescence and tumor progression; however, existing detection probes frequently face challenges such as low water solubility, suboptimal fluorescence quantum yield, and insufficient stability in complex biological environments. To address these limitations, a novel fluorescence probe, QST-GAL, was developed by introducing a sulfonic acid group into a quinoline-based near-infrared dye to improve hydrophilicity and by incorporating a thiophene moiety to extend the conjugation system. The presence of these groups enhances the intramolecular charge transfer of the probe. Under optimal conditions, QST-GAL had a linear detection range of 2-28 U/mL and a low detection limit of 0.377 U/mL. Cellular assays confirmed the probe's ability to visualize breast cancer cells and monitor chemotherapy-induced senescence. Using a breast cancer mouse model, QST-GAL was successfully employed in in vivo tumor imaging, fluorescence-guided surgical resection, and accurate assessment of the Palbociclib's therapeutic effects. This probe offers a promising tool for both diagnosis and treatment monitoring of breast cancer.

The abnormally high expression of glutathione (GSH) in hepatocellular carcinoma (HCC) cells significantly contributes to chemotherapy resistance by neutralizing reactive oxygen species (ROS). To address this problem, we developed a nanocomposite probe (micelle@PDA@MnO2 NPs) which was composed of free radical-labeled micelles as the core, polydopamine (PDA) as the inner shell and MnO2 nanosheets as the outer shell. In the HCC microenvironment, the over-expressed GSH triggered the decomposition of the MnO2 shell, releasing Mn2+ ions, and subsequently, the acidic condition and over-expressed carboxylesterase 2 (CES2) worked together to mediate the controlled release of nitroxide free radicals (i.e., TEMPONE) from the micelle core. With the help of dual-signal electron spin resonance (ESR) detection, it was found that much more free radicals and Mn2+ were released in hepatoma cells than in normal liver cells, rendering the proposed nanotherapeutic platform specific to HCC and a good candidate for free radical therapy and chemodynamic therapy (CDT). Moreover, the therapy featured an intelligent self-amplified property: the abundant GSH in the tumor microenvironment rapidly activated the decomposition of the nanocomposite and triggered the release of free radical TEMPONE and Mn2+, and TEMPONE and Mn2+ further amplified the oxidative stress to induce tumor apoptosis via ROS generation and GSH depletion. Finally, in combination with three therapy modes (Mn2+-mediated CDT, the oxidative stress enhancement effect of TEMPONE, and PDA-based photothermal therapy), significant therapeutic effects including facilitation of HepG2 cell apoptosis and inhibition of tumor growth in the HCC mouse model were achieved.

The lack of precise, real-time analytical tools for monitoring tumor microenvironment changes during treatment hinders advancements in integrated diagnostic and therapeutic platforms. Traditional caspase-3 monitoring strategies are limited by their inability to address drug resistance and newly discovered apoptotic pathways, leading to reduced accuracy and practicality. To overcome these limitations, we developed a fluorescence-based "Trojan horse" nanosystem, PFpR@CM, featuring high-sensitivity Caspase-1 detection, tumor-targeted delivery, and photothermal therapy. Caspase-1 was selected as a biomarker due to its ability to provide accurate feedback on reactive oxygen species (ROS) generation. The system employs Fe-doped polydopamine nanoparticles and red fluorescent carbon quantum dots (RCQDs) as the analytical core, achieving a detection limit of 0.024 U/mL for Caspase-1 with a linear range of 0.05-1.0 U/mL. By integrating MG-63 cell membrane camouflage, PFpR@CM ensures tumor specificity and immune evasion, allowing precise in situ monitoring of ROS production during ferroptosis. Experimental results demonstrate that the system enables simultaneous real-time fluorescence tracking and localized therapeutic interventions, achieving over 80% tumor volume reduction in vivo with minimal systemic toxicity. This work establishes a novel analytical chemistry approach for multifunctional tumor monitoring and treatment, providing an innovative solution to challenges in precision oncology.

Porphyrins possess excellent electrochemiluminescence (ECL) properties but suffer from aggregation-induced quenching (ACQ) in aqueous solutions. Metal-organic frameworks (MOFs) can effectively mitigate this issue by restricting porphyrin aggregation. However, existing studies predominantly focus on cathodic ECL emission at highly negative trigger potentials, which often leads to undesirable hydrogen evolution side reactions. To overcome this challenge, we developed a novel Yb-based MOF (Yb-TCPP) with anodic ECL emission and a low triggering potential. Yb-TCPP was synthesized via the hydrothermal reaction, using 5,10,15,20-tetra(4-carboxyphenyl)-porphyrin (H2TCPP) as the organic linker. Among a series of Yb-MOFs (Yb-ETTC, Yb-CTTB, Yb-BCPP), Yb-TCPP had the strongest ECL emission, with an intensity reaching similar to 11000 a.u. Further modification with gold nanoparticles (AuNPs) significantly enhanced its conductivity and ECL performance. The resulting Yb-TCPP@AuNPs exhibited a low triggering potential of + 0.47 V, effectively avoiding oxygen evolution side reactions. With the Phi(ECL) of [Ru(bpy)(3)](2 +)/triethylamine (TEA) set as 1, it also achieved a high ECL efficiency (Phi(ECL)) of 11 %. These results highlight the potential of Yb-TCPP@AuNPs as a robust anodic ECL material for biosensing applications. Based on this material, we constructed an "on-off" ECL biosensor for the sensitive detection of apurinic/apyrimidinic endonuclease 1 (APE1) using catalytic hairpin amplification (CHA). The sensor had a linear detection range of 1 x 10(-8) U/mL to 1 x 10(-2) U/mL and a detection limit of 1.58 x 10(-9) U/mL. In summary, this study presents the successful development of Yb-TCPP@AuNPs as a promising anodic ECL platform, providing new insights into the development of advanced ECL materials for clinical diagnostics.

Papillary thyroid carcinoma (PTC) is the most prevalent form of thyroid cancer with a high incidence among endocrine malignancies. It tends to metastasize early in lymph nodes and differs markedly from other subtypes in biological behavior, clinical management, and prognosis. Therefore, accurately distinguishing PTC from other pathological subtypes is crucial for guiding diagnosis and treatment decisions. However, conventional methods such as thyroid ultrasound and ultrasound-guided fine-needle aspiration cytology (FNA) have limitations, including sampling errors and low sensitivity. To address these challenges, we developed a novel electrochemiluminescence (ECL) biosensor from CdTe-DNA quantum dots (QDs) and an enzyme-free DNA amplification circuit. In the system, toehold-mediated strand displacement reactions (TSDR) were utilized to generate Cy5-modified DNA strands, which quench the ECL signal via an energy transfer effect. The quenching indicates the presence of thyroid cancer. Catalytic hairpin assembly (CHA) was employed to produce ferrocene (Fc)-labeled DNA strands to enable dual-mode signal modulation (ECL quenching and differential pulse voltammetry (DPV) enhancement) for accurate classification of PTC. Validation experiments demonstrated that the biosensor exhibits excellent sensitivity and a broad dynamic range, enabling the simultaneous detection of BRAF V600E mutations and microRNA-221 (miR-221) expression. This integrated sensing platform offers is a promising tool for the early diagnosis and molecular classification of thyroid cancer.