Nb(2)CTx-supported bimetallic NPs@ZIF-8 nanohybrid as ECL signal amplifier and peroxidase mimics for chromogranin a immunosensing in human serum and saliva.

Niobium carbide (Nb2CTx), a key component of the MXene family renowned for its utilization in lithium-ion batteries and supercapacitors, remains largely underutilized in biosensing applications. This study introduces a notably sensitive and label-free dual-mode electrochemiluminescence (ECL) and colorimetric immunosensor to specifically detect chromogranin A (CgA) in biological fluids. Initially, AuAg bimetallic nanoparticles (BiMNPs) were synthesized using Nb2CTx as a reducing and supporting material. Furthermore, a promising approach has been put forward to increase the efficacy of the ECL of [Ru (bpy)3]2+ system by integrating the combined use of the zeolitic imidazolate framework-8 (ZIF-8) and the Nb2CTx coated bimetallic NPs. Incorporation produces a significant ~165-fold increase in electrochemical signals and a 4-fold improvement in ECL signals. In particular, BiMNPs@ZIF-8 nanohybrid exhibited significantly enhanced peroxidase-like activity compared to bare BiMNPs, demonstrating synergistic peroxidase enzyme mimicry. This improved activity makes it a potent catalyst for the H₂O₂-mediated oxidation of 3,3,5,5, tetramethylbenzidine (TMB), generating the characteristic blue color. Furthermore, the ECL method achieved a detection range of 0.001 to 1000 pg/mL with LOD of 0.11 fg/mL, while the colorimetric method achieved a LOD of 100 pg/mL and a linear range of 0.1 to 4000 ng/mL. The practical applicability of the sensor was validated by analyzing CgA levels in human serum and saliva samples.

Kareem F ，Chau YC ，Ahmed MU 《-》

Electrochemiluminescence immunosensor based on a novel heterostructured Fe-MIL-88@1T-MoS(2) dual-nanozyme with high peroxidase-like activity for the sensitive detection of NT-proBNP.

Jiang X ，Su W ，Shi W ，Wang H ... -  《-》

A sensitive electrochemiluminescence immunosensor for CEA detection based on the ECL-RET between zinc-based metal-organic frameworks and ZiF-8@PDA.

In this study, we developed a new system that using zinc-based metal-organic frameworks NH2-Zn-PTC as the donor and ZiF-8@PDA as the acceptor to achieve highly sensitive detection of carcinoembryonic antigen (CEA), using the fundamentals of electrochemiluminescence resonance energy transfer (ECL-RET). Firstly, the aggregation-induced quenching effect (ACQ) was eliminated by the coordination of PTC in MOF and the ECL signal was improved. Secondly, the ECL signal was further amplified by using Au NPs and amino groups as co-reaction promoters to generate more SO4.-. In addition, the introduction of ZiF-8@PDA as an acceptor and NH2-Zn-PTC as a donor took advantage of the feature of partial overlap of the UV-vis absorption spectrum and ECL emission spectra between the two, thereby effectively initiating the ECL-RET behavior, which improved the detection sensitivity of the sensor. The prepared immunosensor showed good linearity in the concentration range of 10-4 to 80 ng/mL with a detection limit of 18.20 fg/mL. This makes it promising for clinical testing of tumor markers.

Li Y ，Cheng Y ，Ren H ，Ji T ，Zhao Z ，Li H ，Hong C ... -  《-》

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.

《Jove-Journal of Visualized Experiments》

Nanochannel confined graphene quantum dots/platinum nanoparticles boosts electrochemiluminescence of luminal-O(2) system for sensitive immunoassay.

Sensitive detection of tumor biomarkers is of great significance for early cancer diagnosis, treatment evaluation, and recurrence monitoring. Development of convenient electrochemiluminescence (ECL) immunosensor using dissolved oxygen (O2) as an endogenous co-reactant of luminol combined with efficient nanocatalysts to boost ECL signal in neutral media is highly desirable. Herein, sensitive detection of tumor biomarker using ECL of luminal-O2 enhanced by confinement of nitrogen-doped graphene quantum dots (N-GQDs) and platinum nanoparticles (PtNPs) on nanochannel array was demonstrated. A high-density nanochannel array-modified electrode was achieved by rapidly growing an amino-functionalized. Vertically-ordered mesoporous silica film (NH2-VMSF) on the inexpensive and readily available indium tin oxide (ITO) electrode. Through simple electrodeposition, N-GQDs were confined and PtNPs were in-situ synthesized in nanochannels of NH2-VMSF. These confined nanocomposites catalyzed the electroreduction of O2 at negative potentials to generate a large amount of reactive oxygen species (ROS) and facilitated luminol oxidation, enhancing the ECL signal of luminol by 25 times. Two immunosensors were fabricated after covalent immobilization of the recognition antibody of carbohydrate antigen 199 (CA199) or carbohydrate antigen 125 (CA125) on the outer surface of the NH2-VMSF and blocking of non-specific sites. When tumor biomarkers bind to the corresponding antibodies on the recognition interface, the formed immunocomplex hindered the diffusion of luminol to the underlying electrode, resulting in a decrease in the ECL signal and sensitive detection of tumor biomarker. The constructed CA199 immunosensor exhibited a linear detection range for CA199 from 0.5 mU mL-1 to 50 U mL-1, with a detection limit (DL) of 0.03 mU mL-1. For CA125 detection, linear detection ranged from 0.5 mU mL-1 to 500 U mL-1, with a DL of 0.005 mU mL-1. The fabricated immunosensors demonstrated good selectivity and high reproducibility. This study provides great potential for the development of efficient luminol ECL systems in neutral media and expands the biological application in sensitive detection of tumor biomarker.

Zhou Y ，Zhang C ，Liu J ，Mou Y ... -  《-》