Advanced nanomaterials for electrochemical sensors: application in wearable tear glucose sensing technology.

In the last few decades, tear-based biosensors for continuous glucose monitoring (CGM) have provided new avenues for the diagnosis of diabetes. The tear CGMs constructed from nanomaterials have been extensively demonstrated by various research activities in this field and are gradually witnessing their most prosperous period. A timely and comprehensive review of the development of tear CGMs in a compartmentalized manner from a nanomaterials perspective would greatly broaden this area of research. However, to our knowledge, there is a lack of specialized reviews and comprehensive cohesive reports in this area. First, this paper describes the principles and development of electrochemical glucose sensors. Then, a comprehensive summary of various advanced nanomaterials recently reported for potential applications and construction strategies in tear CGMs is presented in a compartmentalized manner, focusing on sensing properties. Finally, the challenges, strategies, and perspectives used to design tear CGM materials are emphasized, providing valuable insights and guidance for the construction of tear CGMs from nanomaterials in the future.

Pathogen detection via inductively coupled plasma mass spectrometry analysis with nanoparticles.

Infections caused by viruses and bacteria pose a significant threat to global public health, emphasizing the critical importance of timely and precise detection methods. Inductively coupled plasma mass spectrometry (ICP-MS), a contemporary approach for pathogen detection, offers distinct advantages such as high sensitivity, a wide linear range, and multi-index capabilities. This review elucidates the underexplored application of ICP-MS in conjunction with functional nanoparticles (NPs) for the identification of viruses and bacteria. The review commences with an elucidation of the underlying principles, procedures, target pathogens, and NP requirements for this innovative approach. Subsequently, a thorough analysis of the advantages and limitations associated with these techniques is provided. Furthermore, the review delves into a comprehensive examination of the challenges encountered when utilizing NPs and ICP-MS for pathogen detection, culminating in a forward-looking assessment of the potential pathways for advancement in this domain. Thus, this review contributes novel perspectives to the field of pathogen detection in biomedicine by showcasing the promising synergy of ICP-MS and NPs.

A review of nanomaterials for biosensing applications.

A biosensor is a device that reacts with the analyte to be analyzed, detects its concentration, and generates readable information, which plays an important role in medical diagnosis, detection of physiological indicators, and disease prevention. Nanomaterials have received increasing attention in the fabrication and improvement of biosensors due to their unique physicochemical and optical properties. In this paper, the properties of nanomaterials such as the size effect, optical and electrical properties, and their advantages in the field of biosensing are briefly summarized, and the application of nanomaterials can effectively improve the sensitivity and reduce the detection limit of biosensors. The advantages of commonly used nanomaterials such as gold nanoparticles (AuNPs), carbon nanotubes (CNTs), quantum dots (QDs), graphene, and magnetic nanobeads for biosensor applications are also reviewed. Besides, the two main types of biosensors using nanomaterials involved in their construction and their working principles are described, and the toxicity and biocompatibility of nanomaterials and the future direction of nanomaterial biosensors are discussed.

Fully integrated wearable microneedle biosensing platform for wide-range and real-time continuous glucose monitoring.

Wearable microneedle sensors for continuous glucose monitoring (CGM) have great potential for clinical impact by allowing access to large data sets to provide individualized treatment plans. To date, their development has been challenged by the accurate wide linear range tracking of interstitial fluid (ISF) glucose (Glu) levels. Here, we present a CGM platform consisting of a three-electrode microneedle electrochemical biosensor and a fully integrated radio-chemical analysis system. The long-term performance of the robust CGM on diabetic rats was achieved by electrodepositing Prussian blue (PB), and crosslinking glucose oxidase (GOx) and chitosan to form a 3D network using glutaraldehyde (GA). After redox by GOx, PB rapidly decomposes hydrogen peroxide and mediates charge transfer, while the 3D network and graphite powder provide enrichment and release sites for Glu and catalytic products, enabling a sensing range of 0.25-35 mM. Microneedle CGM has high sensitivity, good stability, and anti-interference ability. In diabetic rats, CGM can accurately monitor Glu levels in the ISF in real-time, which are highly consistent with levels measured by commercial Glu meters. These results indicate the feasibility and application prospects of the PB-based CGM for the clinical management of diabetes. STATEMENT OF SIGNIFICANCE: This study addresses the challenge of continuous glucose monitoring system design where the narrow linear range of sensing due to the miniaturization of sensors fails to meet the monitoring needs of clinical diabetic patients. This was achieved by utilizing a three-dimensional network of glutaraldehyde cross-linked glucose oxidase and chitosan. The unique topology of the 3D network provides a large number of sites for glucose enrichment and anchors the enzyme to the sensing medium and the conductive substrate through covalent bonding, successfully blocking the escape of the enzyme and the sensing medium and shortening the electron transfer and transmission path.

Biomass-derived 2D carbon materials: structure, fabrication, and application in electrochemical sensors.

Biomass, a renewable hydrocarbon, is one of the favorable sources of advanced carbon materials owing to its abundant resources and diverse molecular structures. Biomass-based two-dimensional carbon nanomaterials (2D-BC) have attracted extensive attention due to their tunable structures and properties, and have been widely used in the design and fabrication of electrochemical sensing platforms. This review embarks on the thermal conversion process of biomass from different sources and the synthesis strategy of 2D-BC materials. The affinity between 2D-BC structure and properties is emphasized. The recent progress in 2D-BC-based electrochemical sensors for health and environmental monitoring is also presented. Finally, the challenges and future development directions related to such materials are proposed in order to promote their further application in the field of electrochemical sensing.