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Cotton thread is promising in fabricating biosensors for diagnostic application due to its excellent characteristics. However, the enrichment of the capture molecules on a narrow zone of the cotton thread based biosensor is a big challenge because of its superhydrophilicity. Here, we report a simple, low-cost and accurate cotton thread based nucleic acid biosensor with temperature-dependent pattern. Liquid wax is used to fabricate temperature-dependent pattern to restrict the test zone in a narrow area. This biosensor enables visual and quantitative detection of target DNA by accumulation of gold nanoparticles (GNPs) on the test zone with a detection limits of 0.75 nM. In addition, the cotton thread based biosensor needs less sample than previous reported lateral flow strip and the sample solution wicks faster at the cotton thread which can lead to a shorter detection time. This simple, low-cost and fast detection method holds great potential to improve healthcare services in the developing regions. [ABSTRACT FROM AUTHOR]

Simultaneous detection of multiple biomarkers is benefit for reducing the detection cycles, avoiding the false-positive signals, and providing the cross validation, which provide the opportunity to understand the pathogenic mechanisms and achieve precise early diagnosis. Here, we demonstrate the mini-pillar-based individual electrochemical array for simultaneous detection of multiple biomarkers. On such platform, the mini-pillar could confine the microdroplet as individual and open-channel microreactor, which is extremely helpful for reducing reagent consumption and extracting internal information, and the electrodes array embedded in mini-pillar are integrated on one side to achieve multiple and simultaneous electrochemical sensing. The introduction of gold nanodendrites by electrodeposition has greatly enhanced sensitivity via improving probe-binding capacity and response signals. Sensitive and selective detection of multiple Alzheimer's biomarkers including Tau, ApoE4, Amyloid-β and miRNA-101 on such mini-pillar-based biosensor is also achieved. Such biosensor platform with the advantages of high-yield, high sensitivity, low-waste and multiple signals output shows great promise in sensing multiple biomolecules for disease diagnosis and health monitoring. • An integrated mini-pillar-based electrochemical sensor is designed. • The optimal gold nanodendrites electrode has the high sensitivity and stability toward electrochemical sensing. • Multiple Alzheimer's biomarkers have been simultaneously detected on such mini-pillar-based electrochemical sensor. [ABSTRACT FROM AUTHOR]

Ultrasound as a biocompatible and powerful approach has been advanced in biotechnology. Here we present an acoustic microchip integrating modification and detection for in-situ analysis. Such microchip employs two pairs of piezoelectric transducers (PZTs) for acoustic field generation and a polydimethylsiloxane (PDMS) microcavity on a polyethylene terephthalate (PET) substrate for producing microparticle array. The applying of acoustic field results in rapidly forming microparticle array by adjusting the inputting frequency and voltage. In-situ modification and detection are accelerated due to the dynamic ultrasonic streaming around the ultrasound induced microparticle array. Such array also benefits from reducing the detection errors by coupling of multiple points. With this strategy, biomarkers (e.g. miRNA) can be enriched, and achieve in-situ modification and detection via simple two steps with excellent specificity. After the detection, samples are regained from the output channel by releasing the acoustic field, which is benefit for further analysis. Such integrated modification and detection acoustic microchip shows great potential in visual in-situ analysis and enriching ultratrace biomarkers for clinical diagnosis. • An acoustic microchip integrating modification and detection for in-situ analysis was designed. • Such ultrasound-based array also benefits from reducing the detection errors by coupling of multiple points. • The acoustic microchip enables rapidly, real-time and visual biomarkers analysis. [ABSTRACT FROM AUTHOR]

High throughput and high sensitivity are two important aspects in multiple biomarker recognition, drug discovery and relevant biochemical sensing. Here, we integrate mini-pillar microarray with the circuit components toward high-throughput individual electrochemical sensing in microdroplets. On such droplet-microarray-based electrochemical platform, the high adhesion of the mini-pillar can hold a microdroplet (hundreds nanoliter to a few microliter) regardless of rotation and deformation. Each pillar as a unit has a three-electrode to achieve individual electrochemical sensing, and electrodes are integrated on one side to achieve the sequential electrochemical read-out. Qualitative and quantitative electrochemical assessments of multiple glucose concentrations in individual microdroplets are also achieved. Such mini-pillar-based individual electrochemical platform shows great potential in high-throughput and high-sensitive biomolecular recognitions, provides an opportunity to develop miniaturized sensing platform for emerging biological and pathological applications. • A mini-pillar-array electrochemical sensor is designed. • The mini-pillar-based electrochemical sensor can anchor the microliter droplets for high throughput biosensing. • The mini-pillar-based platform can achieve sensing of multiple glucose concentrations in array microdroplets. [ABSTRACT FROM AUTHOR]

Continuous physiological monitoring is a promising alternative to current chronic disease management for obtaining big data sets to help individualized therapy. Here, we present a continuous glucose monitoring platform consisting of a screen-printed electrochemical biosensor and a fully integrated wireless electrochemical analysis system. A biocompatible conjugated polymer (poly (N-phenylglycine)) was employed as the support material for enzyme immobilization. Specifically, a polyurethane outer layer was decorated onto the working electrode of the biosensor to construct a diffusion limiting membrane and improve the linear range of the glucose sensor. We optimized the fabricated glucose sensor so that it achieves a linear range of 1–30 mM and a sensitivity of 12.69 μA mM−1·cm−2 in vitro. The long-term stability is up to 30 days by storing in PBS solution at 4°C. The overall system design was very small (0.8 × 1.8 cm) and consisted of a signal conditioning part, a programmable electrochemical chip, and a wireless connection using Bluetooth Low Energy with a smartphone. Finally, we carried out biocompatibility tests and animal experiments to demonstrate the device can successfully monitor blood glucose in vivo. • A flexible, miniaturized and fully integrated wearable CGM system was fabricated. • Chemically synthesized PPG was first employed for GOx immobilization. • Exhibits an excellent linear range of 1–30 mM and long-term stability for 30 days. • The overall system design was very small (0.8 × 1.8 cm). • The biocompatibility tests and animal experiments were carried out. [ABSTRACT FROM AUTHOR]

Catalytic hairpin assembly (CHA) is a promising enzyme-free, isothermal signal amplification strategy, but the relatively time-consuming strand replacement limits its application scenarios. Here, we developed an ultrasound-enhanced catalytic hairpin assembly (UECHA) biosensing platform for early screening of Alzheimer's disease by introducing a portable acoustic-drive platform with functionalized microspheres for effective biomarkers enrichment and fluorescence enhancement. By constructing a gradient ultrasonic field in a microcavity, the platform concentrates the functionalized microspheres in a central position, accompanied by an enhanced fluorescence signal with a specific release. In addition, the programmable frequency modulation can also modify the acoustic potential well and effectively promote non-equilibrium chemical reactions such as CHA (25 min). Compared with the conventional catalytic hairpin assembly (CHA), UECHA allows for direct and quantitative measurement of AD miRNAs down to 3.55 × 10−15 M in 1 μL samples. This visual analysis of ultra-trace biomarkers based on acoustic enrichment and promotion provides a new perspective for the rapid and highly sensitive clinical detection of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) and wearable sensors are two essential fields to realize the goal of tailoring the best precision medicine treatment for individual patients. Integration of these two fields enables better acquisition of patient data and improved design of wearable sensors for monitoring the wearers' health, fitness and their surroundings. Currently, as the Internet of Things (IoT), big data and big health move from concept to implementation, AI-biosensors with appropriate technical characteristics are facing new opportunities and challenges. In this paper, the most advanced progress made in the key phases for future wearable and implantable technology from biosensing, wearable biosensing to AI-biosensing is summarized. Without a doubt, material innovation, biorecognition element, signal acquisition and transportation, data processing and intelligence decision system are the most important parts, which are the main focus of the discussion. The challenges and opportunities of AI-biosensors moving forward toward future medicine devices are also discussed. • Progress for wearable and implantable technology from biosensing, wearable biosensing to AI-biosensing is summarized. • We emphasized the materials, biorecognition, signal processing, and intelligence decision for AI-biosensor. • The challenges and opportunities of AI-biosensors moving forward toward future medicine devices are also discussed. [ABSTRACT FROM AUTHOR]

Simple, effective, and rapid detection of chemically relevant hazards is a highly desirable research goal, which can provide early-warning information to improve the patient-care outcomes for public health. Here, we introduce a microdroplet-captured tape toward rapid SERS screening of food contaminants. The dominant sensing unit lies on functionalized microwell in conductive carbon tapes, which is simply prepared by physical punching, magnetron sputtering and electrochemical deposition of Au nanodendrites. The tape-based sensors not only possess highly branched Au nanodendrites in microwell for promoting SERS activity, but also enable anchoring the microdroplets via direct dip-pulling from pristine analytes solutions upon sticky incorporated on a glove. Early-warning SERS detection of food contaminants including Sudan-1, thiram, and thiabendazole from the real samples can be achieved by such simple sampling method. These tape-based sensors with a facile operation module and accessible signal read-out represent an innovative point-of-care testing (POCT) device for forensic, military, consumer protection, environmental monitoring, and food safety applications. • The tape-based sensors within Au nanodendrites-modified microwell was designed. • High capillary force among microwell enables rapidly sampling analytes solution. • On-site SERS analysis of real food contaminants in daily life was achieved. [ABSTRACT FROM AUTHOR]

Long-term wearing comfort is essential for future advanced electronic textiles (e-textiles). Herein, we fabricate a skin-comfortable e-textile for long-term wearing experience on human epidermis. Such e-textile was simply fabricated through two different dip coating methods and single-side air plasma treatment, which couples radiative thermal and moisture management for biofluid monitoring. The silk-based substrate with improved optical properties and anisotropic wettability can provide a temperature drop of 1.4 °C under strong sunlight. Moreover, the anisotropic wettability of the e-textile can provide a dryer skin microenvironment by comparing with traditional fabric. The fiber electrodes weaving into the inner side of the substrate can noninvasively monitor multiple sweat biomarkers (i.e., pH, uric acid, and Na+). Such a synergistic strategy may pave a new path to design next-generation e-textiles with significantly improved comfort. [ABSTRACT FROM AUTHOR]

The outbreak of COVID-19 has created a huge challenge to global health systems. Experience in fighting the epidemic shows that the development of a rapid and sensitive POCT diagnostic platform for SARS-CoV-2 that can be deployed in situ is crucial to contain the outbreak. Here, we have developed a portable microdroplet detection platform that integrated temperature controller and micro-stirring for high-throughput and ultrafast COVID-19 diagnosis. Such a device uses a p-n junction (PN junction) as the temperature controller to adjust the temperature in a single microdroplet independently and precisely, ensuring the amplification of reverse transcription loop-mediated isothermal amplification (RT-LAMP). Meanwhile, the platform incorporates an ultrasonic micro-stirring unit, greatly increasing the interaction between RT-LAMP molecules and accelerating the amplification. The results show good linearity over a wide linear range (1 to 105 copies/μL) and low LOD (0.48 copy/μL). Our method reports in only 6.1 min for high-viral load samples, and combines with sample preparation, the total detection process could be done within 30 min. Such a portable and fully integrated microdroplet molecular diagnostic platform is a promising tool for point-of-care diagnosis of COVID-19 and other infectious diseases in resource-limited settings. [Display omitted] • A portable microdroplet array integrated platform for SARS-CoV-2 detection. • The temperature of each microdroplet can be independently and precisely controlled. • Ultrasound-induced microstreaming can enhance the RT-LAMP reaction. • The method presents a low LOD with 0.48 copy/μL and detection time in only 6.1 min. • Such fully integrated device holds promise for rapid and sensitive detection in clinical diagnosis. [ABSTRACT FROM AUTHOR]

Rapid detection and accurate analysis of trace samples is an important prerequisite for precision medicine. Here we integrated capillary with ultrasound to induce biomarkers enrichment in nanoliter samples, and developed a nanoliter sample enrichment analysis method for ultra-trace miRNA biosensing. The interaction between ultrasonic field and capillary provides a gradient ultrasound field, which is essential for the aggregation of functionalized microspheres along with the enrichment of specific biomarkers. The results indicated that the enrichment of the biomarkers effectively enhanced the fluorescence intensity, and the limit of detection reaches 7.8✕10−12 M in 100 nL. Such integrated device can realize ultrasonic enrichment and visual analysis of target samples, and provides a new idea for rapid and highly sensitive detection of ultra-trace biomarkers in clinical diagnosis. • A nanoliter sample enrichment detection method for ultra-trace miRNA biosensing. • Integrated capillary with ultrasound enables capture and enrichment of specific trace biomarkers. • Such integrated device provides a new idea for rapid and highly sensitive detection in clinical diagnosis. [ABSTRACT FROM AUTHOR]