In situ reduction of gold nanoparticles-decorated MXenes-based electrochemical sensing platform for KRAS gene detection

Integrating isothermal amplification techniques and LNA-based AI-assisted electrochemical bioassay for analysis of KRAS G12V point mutation

The KRAS mutation is a crucial biomarker for determining targeted cancer therapies, making its accurate and cost-effective detection vital for precision oncology. However, current methodologies, such as next-generation sequencing (NGS) or PCR-based methods, are often expensive and technically complex, limiting their accessibility. Here, we present a novel bioassay for KRAS G12V mutation analysis that combines rolling circle amplification (RCA) with locked nucleic acid (LNA)-modified magnetic beads, electrochemical detection using carbon electrode chips, and AI-assisted analysis via a logistic regression classifier. Our platform demonstrated exceptional selectivity in distinguishing the KRAS G12V mutation from wild-type (wt) sequences, enabling analysis <1 % of mutated DNA in a wt sample. We validated the bioassay on 7 cancer cell lines and 11 patient-derived samples, achieving results that perfectly correlated with NGS data. This innovative approach simplifies the workflow, reduces costs, and offers high sensitivity and specificity, making it a promising tool for clinical diagnostics and personalized cancer treatment strategies.

Exploring the frontiers of X@MXene nanozymes: Synthesis, enhanced catalytic mechanism, and application in biomedical sensors

Biosensing technologies are facing increasingly urgent demands for highly sensitive and selective sensors. MXene, as a novel two-dimensional (2D) material, has emerged as an ideal candidate for sensors due to its ultrahigh conductivity and tunable surface functional groups. However, unmodified MXene lacks catalytic activity and specificity, limiting its applications. Surface-engineered X@MXene composites (X = metal oxides, aptamers, etc.) can significantly enhance catalytic activity and selectivity. This review systematically summarizes MXene synthesis strategies (HF etching, HF-free etching, vapor deposition, surface terminal group modulation), elucidates the regulatory mechanism of heterocomponents (X) on MXene catalytic pathways, analyzes its design principles in single-mode devices with different signal types (optical, electrical, colorimetric), and reveals the synergistic advantages of dual-mode sensors in sensitivity and anti-interference performance. This review provides theoretical guidance for designing high-performance MXene-based sensors, advancing their applications in precision medicine and intelligent monitoring.

Recent advances using MXenes in biomedical applications

An MXene is a novel two-dimensional transition metal carbide or nitride, with a typical formula of Mn+1XnTx (M = transition metals, X = carbon or nitrogen, and T = functional groups). MXenes have found wide application in biomedicine and biosensing, owing to their high biocompatibility, abundant reactive surface groups, good conductivity, and photothermal properties. Applications include photo- and electrochemical sensors, energy storage, and electronics. This review will highlight recent applications of MXene and MXene-derived materials in drug delivery, tissue engineering, antimicrobial activity, and biosensors (optical and electrochemical). We further elaborate on recent developments in utilizing MXenes for photothermal cancer therapy, and we explore multimodal treatments, including the integration of chemotherapeutic agents or magnetic nanoparticles for enhanced therapeutic efficacy. The high surface area and reactivity of MXenes provide an interface to respond to the changes in the environment, allowing MXene-based drug carriers to respond to changes in pH, reactive oxygen species (ROS), and electrical signals for controlled release applications. Furthermore, the conductivity of MXene enables it to provide electrical stimulation for cultured cells and endows it with photocatalytic capabilities that can be used in antibiotic applications. Wearable and in situ sensors incorporating MXenes are also included. Major challenges and future development directions of MXenes in biomedical applications are also discussed. The remarkable properties of MXenes will undoubtedly lead to their increasing use in the applications discussed here, as well as many others.

A novel Cu-MOFs nanosheet/BiVO4 nanorod-based ECL sensor for colorectal cancer diagnosis

Although luminescence metal organic framework (MOFs) has displayed the significant advantages, the limitations in the electrochemical performance (e.g. rapid charge recombination rates and inadequate charge transport) limited the sensing application of MOFs. Herein, a novel Cu-MOFs/BiVO4 nanorod-based electrogenerated chemiluminescence (ECL) sensor has been developed. Firstly, Cu-MOFs with strong luminescence were synthesized via the three-layer approach as ECL emitter. Furthermore, BiVO4 nanorods was modified on the electrode as the actuator to improve the electrochemical activity of Cu-MOFs in the ECL process. As an n-type semiconductor, BiVO4 formed a complementary structure with p-type semiconductor Cu-MOF. Therefore, electrons in the conduction band of BiVO4 transferred to that of Cu-MOF. As a result, more electrons reacted with coreactant on the surface of Cu-MOF, which effectively enhanced the ECL performance of 2D Cu-MOFs nanosheets. As a result, the quantitation of KRAS gene was realized in the linear range of 0.1 pM-1 nM with a detection limit of 0.02 fM. Moreover, the detection of KRAS gene in actual colorectal cancer samples was also carried out with good recovery, which offered a broad application possibility for ECL research and clinical analysis.