Plug-and-play smart transistor bio-chips implementing point-of-care diagnosis of AMI with modified CRISPR/Cas12a system

Novel approaches in CRISPR/Cas12a-based sensing for HCC diagnosis - A review (2020-2025)

Early diagnosis of hepatocellular carcinoma (HCC) is crucial for improving patient survival and treatment outcomes and the early detection of biomarkers for HCC is key to achieving this goal. However, conventional detection methods often lack sufficient specificity and sensitivity. In recent years, CRISPR/Cas12a-based biosensing has gained significant attention due to its ease of use and high sensitivity, demonstrating its potential to address the limitations of conventional detection methods. This paper primarily reviews the research progress of CRISPR/Cas12a-based biosensors for HCC detection, introducing their fluorescence, electrochemical, colorimetric, and other detection principles, as well as practical applications in detail. Additionally, the differences in sensitivity, specificity, and detection speed among different types of CRISPR/Cas12a biosensors are comparatively analyzed. Finally, the potential future directions for the development and application of CRISPR/Cas12a technology in clinical settings are explored.

Hydrogel-based 3D printing technology: From interfacial engineering to precision medicine

Advances in 3D printing technology and the development of hydrogel-based inks have significantly enhanced the potential of precision medicine, promoting progress in medical diagnosis and treatment. The development of 3D printing enables the fabrication of complex gradient structures that emulate natural tissue environments, while advancements in interface engineering facilitate the precise control of interface properties, thereby enhancing the performance of hydrogels in biomedical applications. This review focuses on the latest advancements in three critical 3D printing application areas: efficient real-time detection, drug delivery systems, and regenerative medicine. The application of 3D printing technology enhances nucleic acid-based molecular diagnostic platforms and wearable biosensors for real-time monitoring of physiological parameters, thereby providing robust support for early disease diagnosis. Additionally, it facilitates the development of targeted and controlled drug delivery systems, which offer promising methods for efficient drug utilization, and enables the construction of complex tissue and organ structures with bioactivity and functionality, providing new solutions for regenerative medicine. Collectively, these advancements propel the ongoing progress and development of precision medicine. Furthermore, the challenges associated with 3D printing technology in these three major applications are discussed along with an outlook on prospects.

High-efficiency detection of APE1 using a defective PAM-driven CRISPR-Cas12a self-catalytic biosensor

The trans-cleavage activity of the CRISPR-Cas system offers tremendous potential for developing highly sensitive and selective molecular diagnostic tools. However, conventional methods often face challenges such as limited catalytic efficiency of single Cas proteins and the necessity of complex multi-enzyme preamplification steps. To address these limitations, we present a novel defective PAM-mediated CRISPR-Cas12a self-catalytic signal amplification strategy, termed DEP-Cas-APE, for the rapid, sensitive, and specific detection of apurinic/apyrimidinic endonuclease 1 (APE1) activity. This approach integrates defective PAM-modified DNA probes to synergize Cas12a trans-cleavage with self-catalytic circuit, achieving efficient signal transformation and amplification under isothermal, one-step conditions. We systematically investigated the influence of defective PAM sequences containing apurinic/apyrimidinic (AP) sites on Cas12a activation and validated the feasibility of the DEP-Cas-APE strategy in detecting APE1. Under optimized conditions, DEP-Cas-APE achieved a detection limit as low as 7.66 × 10-8 U μL-1 within 30 min using a simple isothermal reaction. Additionally, we developed a point-of-care testing (POCT) platform by integrating DEP-Cas-APE with a colorimetric assay based on gold nanoparticles (AuNPs), enabling portable, equipment-free detection. This sensitive and selective strategy successfully detected APE1 in complex biological samples, including serum from lung cancer patients, and demonstrated the ability to distinguish cancerous from normal samples. DEP-Cas-APE represents a robust and versatile platform for advancing CRISPR-Cas12a biosensing technologies, offering new opportunities for molecular diagnostics and clinical research.

Integration Strategies and Formats in Field-Effect Transistor Chemo- and Biosensors: A Critical Review

The continuous advances in micro- and nanofabrication technologies have inevitably led to major improvements in field-effect transistor (FET) design and architecture, significantly reducing the component footprint and enabling highly efficient integration into many electronic devices. Combined efforts in the areas of materials science, life sciences, and electronic engineering have unlocked opportunities to create ultrasensitive FET chemo- and biosensor devices that are coupled with more diverse and complex integration requirements in terms of hardware interfacing, reproducible functionality, and handling of analyte samples. Integration of FET chemo- and biosensors remains one of the major bottlenecks in bridging the gap between fundamental research concepts and commercial sensing devices. In this review, we critically discuss different strategies and formats of integration in the context of key requirements, fabrication scalability, and device complexity. The intentions of this review are 1) to provide a practical overview of successful FET sensor integration approaches, 2) to identify crucial challenges and factors limiting the extent of FET sensor integration, and 3) to highlight promising perspectives for future developments of FET sensor integration. We believe that our structured insights will be helpful for scientists and engineers of various profiles focusing on the design and development of FET-based chemo- and biosensor devices.

How Close Are We to Patient-Side Troponin Testing?

Laboratory-based high-sensitivity cardiac troponin testing has been the pillar for emergency stratification of suspected acute coronary syndrome for well over a decade. Point-of-care troponin assays achieving the requisite analytical sensitivity have recently been developed and could accelerate such assessment. This review summarises the latest assays and describes their potential diverse clinical utility in the emergency department, community healthcare, pre-hospital, and other hospital settings. It outlines the current clinical data but also highlights the evidence gap, particularly the need for clinical trials using whole blood, that must be addressed for safe and successful implementation of point-of-care troponin analysis into daily practice. Additionally, how point-of-care troponin testing can be coupled with advances in biosensor technology, cardiovascular screening, and triage algorithms is discussed.

Label-Free Field Effect Transistors (FETs) for Fabrication of Point-of-Care (POC) Biomedical Detection Probes

Field effect transistors (FETs)-based detection probes are powerful platforms for quantification in biological media due to their sensitivity, ease of miniaturization, and ability to function in biological media. Especially, FET-based platforms have been utilized as promising probes for label-free detections with the potential for use in real-time monitoring. The integration of new materials in the FET-based probe enhances the analytical performance of the developed probes by increasing the active surface area, rejecting interfering agents, and providing the possibility for surface modification. Furthermore, the use of new materials eliminates the need for traditional labeling techniques, providing rapid and cost-effective detection of biological analytes. This review discusses the application of materials in the development of FET-based label-free systems for point-of-care (POC) analysis of different biomedical analytes from 2018 to 2024. The mechanism of action of the reported probes is discussed, as well as their pros and cons were also investigated. Also, the possible challenges and potential for the fabrication of commercial devices or methods for use in clinics were discussed.

A portable transistor immunosensor for fast identification of porcine epidemic diarrhea virus

Widespread distribution of porcine epidemic diarrhea virus (PEDV) has led to catastrophic losses to the global pig farming industry. As a result, there is an urgent need for rapid, sensitive and accurate tests for PEDV to enable timely and effective interventions. In the present study, we develop and validate a floating gate carbon nanotubes field-effect transistor (FG CNT-FET)-based portable immunosensor for rapid identification of PEDV in a sensitive and accurate manner. To improve the affinity, a unique PEDV spike protein-specific monoclonal antibody is prepared by purification, and subsequently modified on FG CNT-FET sensor to recognize PEDV. The developed FET biosensor enables highly sensitive detection (LoD: 8.1 fg/mL and 100.14 TCID50/mL for recombinant spike proteins and PEDV, respectively), as well as satisfactory specificity. Notably, an integrated portable platform consisting of a pluggable FG CNT-FET chip and a portable device can discriminate PEDV positive from negative samples and even identify PEDV and porcine deltacoronavirus within 1 min with 100% accuracy. The portable sensing platform offers the capability to quickly, sensitively and accurately identify PEDV, which further points to a possibility of point of care (POC) applications of large-scale surveillance in pig breeding facilities.

Ultra-sensitive and rapid detection of Salmonella enterica and Staphylococcus aureus to single-cell level by aptamer-functionalized carbon nanotube field-effect transistor biosensors

Foodborne diseases caused by Salmonella enterica (S. enterica) and Staphylococcus aureus (S. aureus) significantly impact public health, underscoring the imperative for highly sensitive, rapid, and accurate detection technologies to ensure food safety and prevent human diseases. Nanomaterials hold great promise in the development of high-sensitivity transistor biosensors. In this work, field-effect transistor (FET) comprising high-purity carbon nanotubes (CNTs) were fabricated and modified with corresponding nucleic acid aptamers for the high-affinity and selective capture of S. enterica and S. aureus. The aptamer-functionalized CNT-FET biosensor demonstrated ultra-sensitive and rapid detection of these foodborne pathogens. Experimental results indicated that the biosensor could detect S. enterica at a limit of detection (LOD) as low as 1 CFU in PBS buffer, and S. aureus at an LOD of 1.2 CFUs, achieving single-cell level detection accuracy with exceptional specificity. The biosensor exhibited a rapid response time, completing single detections within 200 s. Even in the presence of interference from six complex food matrices, the biosensor maintained its ultra-sensitive (3.1 CFUs) and rapid response (within 200 s) characteristics for both pathogens. The developed aptamer-functionalized CNT-FET biosensor demonstrates a capability for low-cost, ultra-sensitive, label-free, and rapid detection of low-abundance S. enterica and S. aureus in both buffer solutions and complex environments. This innovation holds significant potential for applying this detection technology to on-site rapid testing scenarios, offering a promising solution to the pressing need for efficient and reliable pathogen monitoring in various settings.