Self-powered biosensing sutures for real-time wound monitoring.

Effective wound management has the potential to reduce both the duration and cost of wound healing. However, traditional methods often rely on direct observation or complex and expensive biological testing to monitor and evaluate the invasive damage caused by wound healing, which can be time-consuming. Biosensors offer the advantage of precise and real-time monitoring, but existing devices are not suitable for integration with sensitive wound tissue due to their external dimensions. Here, we have designed a self-powered biosensing suture (SPBS) based on biofuel cells to accurately monitor glucose concentration at the wound site and promote wound healing. The anode of the SPBS consists of carbon nanotubes-modified carbon fibers, tetrathiafulvalene (TTF), and glucose oxidase (GOx), while the cathode is composed of Ag2O and carbon nanotubes modified nanotubes modified carbon fibers. It was observed that SPBS exhibited excellent physical and chemical stability in vitro. Regardless of different bending degrees or pH values, the maximum power density of SPBS remained above 92%, which is conducive to long-term dynamic evaluation. Furthermore, the voltage generated by SPBS reflects blood glucose concentration, and measurements at wound sites are consistent with those obtained using a commercially available blood glucose meter. SPBS achieves the healing effect of traditional medical sutures after complete healing within 14 days. It offers valuable insights for intelligent devices dedicated to real-time wound monitoring.

The Denoising Method for Transformer Partial Discharge Based on the Whale VMD Algorithm Combined with Adaptive Filtering and Wavelet Thresholding.

Partial discharge (PD) is the primary factor causing insulation degradation in transformers. However, the collected signals of partial discharge are often contaminated with significant noise. This makes it difficult to extract the PD signal and hinders subsequent signal analysis and processing. This paper proposes a denoising method for transformer partial discharge based on the Whale VMD algorithm combined with adaptive filtering and wavelet thresholding (WVNW). First, the WOA is used to optimize the important parameters of the VMD. The selected mode components from the VMD decomposition are then subjected to preliminary denoising based on the kurtosis criterion. The reconstructed signal is further denoised using the Adaptive Filter (NLMS) algorithm to remove narrowband interference noise. Finally, the residual white noise is eliminated using the Wavelet Thresholding algorithm. In simulation experiments and practical measurements, the proposed method is compared quantitatively with previous methods, VMD-WT, and EMD-WT, based on metrics such as SNR, RMSE, NCC, and NRR. The results indicate that the WVNW method effectively suppresses noise interference and restores the original PD signal waveform with high waveform similarity while preserving a significant amount of local discharge signal features.

Chemical antifouling strategies in sensors for food analysis: A review.

Surface biofouling induced by the undesired nonspecific adsorption of foulants (e.g., coexisting proteins and cells) in food matrices is a major issue of sensors for food analysis, hindering their reliability and accuracy of sensing. This issue can be addressed by developing antifouling strategies to prevent or alleviate nonspecific binding. Chemical antifouling strategies involve the use of chemical modifiers (i.e., antifouling materials) to strongly hydrate the surface and reduce surface biofouling. Through appropriate immobilization approaches, antifouling materials can be tethered onto sensors to form antifouling surfaces with well-ordered structures, balanced surface charges, and appropriate surface density and thickness. A rational antifouling surface can reduce the matrix effect, simplify sample pretreatment, and improve analytical performance. This review summarizes recent developments in chemical antifouling strategies in sensing. Surface antifouling mechanisms and common antifouling materials are described, and factors that may influence the antifouling effects of antifouling surfaces and approaches incorporating antifouling materials onto sensing surfaces are highlighted. Moreover, the specific applications of antifouling sensors in food analysis are introduced. Finally, we provide an outlook on future developments in antifouling sensors for food analysis.

Defect-Enriched Graphene Nanoribbons Tune the Adsorption Behavior of the Mediator to Boost the Lactate/Oxygen Biofuel Cell.

Owing to the high efficiency and specificity in moderate conditions, enzymatic biofuel cells (EBFCs) have gained significant interest as a promising energy source for wearable devices. However, the instability of the bioelectrode and the lack of efficient electrical communication between the enzymes and electrodes are the main obstacles. Herein, defect-enriched 3D graphene nanoribbons (GNRs) frameworks are fabricated by unzipping multiwall carbon nanotubes, followed by thermal annealing. It is found that defective carbon shows stronger adsorption energy towards the polar mediators than the pristine carbon, which is beneficial to improving the stability of the bioelectrodes. Consequently, the EBFCs equipped with the GNRs exhibit a significantly enhanced bioelectrocatalytic performance and operational stability, delivering an open-circuit voltage and power density of 0.62 V, 70.7 µW/cm2, and 0.58 V, 18.6 µW/cm2 in phosphate buffer solution and artificial tear, respectively, which represent the high levels among the reported literature. This work provides a design principle according to which defective carbon materials could be more suitable for the immobilization of biocatalytic components in the application of EBFCs.

Biomimetic functional material-based sensors for food safety analysis: A review.

Food may be contaminated by various hazardous substances in all stages of the food supply chain, which may pose a wide variety of human health risks. The ability to construct sensors capable of highly selective analysis in complex food matrix could offer strong support for guaranteeing food safety. The design, preparation, and introduction of biomimetic functional materials as antifouling materials or recognition receptors provide new ideas for further improvement of the anti-interference and specificity of sensory system. Herein, biomimetic functional materials commonly used in sensor preparation, including biomimetic antifouling materials [poly(ethylene glycol), zwitterionic polymers, and synthetic antifouling peptides] and biomimetic recognition receptors (molecularly imprinted polymers, aptamers, and mimetic recognition peptides) are reviewed. The mechanisms, advantages, limitations of these biomimetic functional materials and the applications of biomimetic functional material-based sensors in food safety analysis are summarized. Finally, the challenges and prospects of sensors based on biomimetic functional materials are analyzed.

Nucleic Acid-Based Cell Surface Engineering Strategies and Their Applications.

The cell membrane is a biological interface regulating the communications between cells and their environment. The ability to functionalize the cell membrane with molecules or nanomaterials allows us to manipulate cellular behaviors and to expand cellular functions. Due to their unique merits of synthetic accessibility, flexible design, and precise programmability, nucleic acids provide an emerging and promising molecular toolkit for cell surface engineering. In this review, the recent progress in nucleic acid-based cell surface engineering are summarized. We first introduce approaches to nucleic acid-based cell surface engineering, including monovalent and polyvalent surface engineering strategies. Then, the biological applications of nucleic acid-based cell surface engineering in biosensing of extracellular microenvironment, programming cell-cell interactions, and mimicking cellular behaviors are reviewed. Finally, we analyze the current challenges existing in this area and discuss the prospects for the future development.

DNA derived N-doped 3D conductive network with enhanced electrocatalytic activity and stability for membrane-less biofuel cells.

Enzymes are promising electrocatalysts in many biological processes. We proposed two strategies, co-immobilization and three-dimensional (3D) space design, to strengthen electron transfer (ET). In this research, DNA base and CNT were mixed in an aqueous solution; then the mixture was dried and ground. Finally, the powder was annealed in N2 to obtain DNA derived N-doped 3D conductive network (N-G@CNT). N-G@CNT immobilized mediators on itself through adsorption. Such 3D space structure shows high activity toward a set of critical electrochemical reactions and high-performance in enzymatic biofuel cells (EBFCs). It is found that N-G@CNT conductive network possesses an interconnected porous structure and well-developed porosity. As a result, the membrane-less EBFCs equipped with enzyme/mediator co-immobilization N-G@CNT bioelectrodes were measured in a model 5 mM glucose-containing aqueous solution, human serum, and rabbit whole blood, respectively, which can generate 0.34, 0.078, and 0.15 mW cm-2 power density, respectively. The constant-current discharge method carried out in a model 5 mM glucose-containing aqueous solution shows that the discharge time reached 19 h at a discharge current density of 0.01 mA cm-2. The membrane EBFCs can deliver a high open circuit voltage of 0.68 V, a short-circuit current density of 2 mA cm-2, and a maximum power density of 0.5 mW cm-2.

Cobalt sulfides/carbon nanohybrids: a novel biocatalyst for nonenzymatic glucose biofuel cells and biosensors.

Exploring high-performance electrocatalysts is of great importance in developing nonenzymatic biofuel cells. Hybrid nanostructures with transition metal compounds and carbon nanomaterials exhibit excellent electrocatalytic activity and have emerged as promising low-cost alternatives for various electrochemical reactions. Herein, we report cobalt sulfide/carbon nanohybrids via a facile synthesis, which have excellent electrocatalytic activity for glucose oxidation and oxygen reduction reaction. The nonenzymatic glucose biofuel cells equipped with cobalt sulfide/carbon nanohybrids deliver a high open circuit voltage of 0.72 V with a maximum open power density of 88 µW cm-2, indicating that cobalt sulfide/carbon nanohybrids are high performance biocatalysts for bioenergy conversion.