Continuous monitoring of multiple biomarkers with an ultrasensitive 3D-structured wearable biosensor.

Chronic diseases call for routine management of frequent monitoring of specific biomarkers. Traditional in vitro diagnostics technologies suffer from complex sampling processes and long detection intervals, which cannot meet the need of continuous monitoring. Wearable devices taking advantage of compact size, rapid detection process, and small sample consumption are promising to take the place of endpoint detection, providing more comprehensive information about human health. Here, we proposed a fully integrated wearable system with an ultrasensitive 3D-structured biosensor for real-time monitoring of multiple metabolites. The 3D-structured biosensor shows wide linear ranges of 400-1,400 µM and 0.1-8 mM and high sensitivities of 460.5 and 283.09 µA/(mM·cm2) for lactate and glucose detection, respectively. We have conducted in vivo animal experiments, and the proposed wearable biosensor demonstrated high consistency with established methods. We envision that this system could provide a real-time wearable detection platform for multiple biomarker detection.

A Flexible Dual-Analyte Electrochemical Biosensor for Salivary Glucose and Lactate Detection.

Electrochemical biosensors have been widely applied in the development of metabolite detection systems for disease management. However, conventional intravenous and fingertip blood tests are invasive and cannot track dynamic trends of multiple metabolites. Among various body fluids, saliva can be easily accessed and is regarded as a promising candidate for non-invasive metabolite detection. Recent works on the development of electrochemical biosensors for monitoring salivary metabolites have demonstrated high sensitivity and wide linear range. However, most of this research has been focused on salivary detection of a single metabolite. Here, we present a dual-channel electrochemical biosensor for simultaneous detection of lactate and glucose in saliva based on a flexible screen-printed electrode with two working electrodes. The sensitivities of glucose and lactate channels were 18.7 µA/(mM·cm2) and 21.8 µA/(mM·cm2), respectively. The dual-channel biosensor exhibited wide linear ranges of 0-1500 µM for the glucose channel and 0-2000 µM for the lactate channel and the cross-talk between the two detection channels was negligible, which made it adequately suitable for sensing low-level salivary metabolites. Such attractive characteristics demonstrate the potential of this dual-analyte biosensor in the development of wearable devices for monitoring disease progression and fitness.

PYTAF: A Python Tool for Spatially Resampling Earth Observation Data.

Earth observation data have revolutionized Earth science and significantly enhanced the ability to forecast weather, climate and natural hazards. The storage format of the majority of Earth observation data can be classified into swath, grid or point structures. Earth science studies frequently involve resampling between swath, grid and point data when combining measurements from multiple instruments, which can provide more insights into geophysical processes than using any single instrument alone. As the amount of Earth observation data increases each day, the demand for a high computational efficient tool to resample and fuse Earth observation data has never been greater. We present a software tool, called pytaf, that resamples Earth observation data stored in swath, grid or point structures using a novel block indexing algorithm. This tool is specially designed to process large scale datasets. The core functions of pytaf were implemented in C with OpenMP to enable parallel computations in a shared memory environment. A user-friendly python interface was also built. The tool has been extensively tested on supercomputers and successfully used to resample the data from five instruments on the EOS-Terra platform at a mission-wide scale.

A 3D electrochemical biosensor based on Super-Aligned Carbon NanoTube array for point-of-care uric acid monitoring.

Uric acid analysis is extremely important for gout prognosis, diagnosis and treatment. Previous technologies either lack specificity or exhibit poor performance, and thus could not meet the need of Point-of-Care (POC) uric acid monitoring. Here we present for the first time, a novel electrochemical biosensor based on 3D Super-Aligned Carbon NanoTube (SACNT) array to facilitate POC uric acid monitoring. The working electrode of the biosensor is composed of an orderly 3D SACNT array immobilized with uricase through a precipitation and crosslinking procedure. Such biosensor possesses a higher enzyme density, significantly larger contact area with reactants and could maintain the intact SACNT structure and its excellent conductivity after modification. The developed 3D SACNT array electrochemical biosensor benefits from high specific surface area, high electro-catalytic activity and large contact area with analytes, and demonstrates high sensitivity of 518.8 µA/(mM⋅cm2), wide linear range of 100-1000 µM and low limit of detection of 1 µM for uric acid. Dynamic uric acid monitoring has been achieved using the presented biosensor. And the obtained results in serum samples had no significant difference compared with those obtained using the FDA-approved electrochemical analyzer (Paired T-test, p > 0.05). These demonstrated that the technology can potentially be applied in POC monitoring of other biomolecules to improve prognosis, diagnosis and treatment outcomes of metabolic diseases.

A movable type bioelectronics printing technology for modular fabrication of biosensors.

Biosensors have been widely used in various fields such as food industry, environmental testing and medical testing for their high sensitivity. However, current fabrication methods of biosensors, such as screen printing, micro fabrication and 3D printing suffer from complex procedures, requirement of cleanroom facility and limited fabrication materials, which significantly restrict the development and utilization of biosensors. Here, we propose a movable type bioelectronics printing method for the fabrication of biosensors by directly transferring bioelectronic materials onto various substrates using pre-fabricated molds. This simple, low-cost, yet robust method facilitates on-demand printing of master molds of partial or complete circuits on both rigid or flexible substrates. With this method, bioactive materials such as enzymes can be directly transferred onto substrates together with other electronic components, without complex modification after electrode fabrication using conventional methods. For demonstration, a dual-channel flexible electrochemical biosensor was fabricated by the movable type bioelectronics printing method for continuous monitoring of glucose and lactate. The movable type bioelectronics printing technology holds advantages of repeatability, flexibility and low cost for fabrication of biosensors on rigid and flexible substrates, as well as direct transfer printing of bioactive materials, which greatly promotes small-scale production of biosensors.

Removal of both cationic and anionic contaminants by amphoteric starch.

A novel amphoteric starch incorporating quaternary ammonium and phosphate groups was applied to investigate the efficiency and mechanism of cationic and anionic contaminant treatment. Its flocculation abilities for kaolin suspension and copper-containing wastewater were evaluated by turbidity reduction and copper removal efficiency, respectively. And the kinetics of formation, breakage and subsequent re-formation of aggregates were monitored using a Photometric Dispersion Analyzer (PDA) and characterized by flocculation index (FI). The results showed that amphoteric starch possessed the advantages of being lower-dosages-consuming and being stronger in shear resistance than cationic starch, and exhibited a good flocculation efficiency over a wide pH range from 3.0 to 11.0.