No abstract

By combining the distinctive noninvasive feature with the peculiar complete functional implementation trait, fully integrated raw noninvasive biofluid glucose biosensors offer active and remote glucose monitoring while posing minimal harm or infection risks compared to the traditional invasive manner. However, each previously reported fully integrated raw noninvasive biofluid glucose biosensor is solely focused on single-type raw noninvasive biofluid analysis. Given the diversity and complexity of subjects' physical conditions, single-type raw noninvasive biofluids are inappropriate to all crowds (e.g., sweat collection/analysis could be inapplicable for dermatopathic subjects). Here, we demonstrate the first example of a universal fully integrated nanoelectronic system with the unique capability to point-of-care and universally monitor diverse raw noninvasive biofluid (i.e., sweat, tears, and saliva) glucose by combining a flexible and disposable microfluidic enzymatic biosensor (named iezSlice) for raw biofluid pump-free sampling and measurement with a customized, handheld, and reusable wireless electronic device (named iezBar) for electrical signal transduction, conditioning, processing, and wireless transmission. We employed the specially designed highconcentration-buffer powder-loaded Kimwipes (HBP-KWs) as the microfluidic channel (microchannel) of iezSlice, guaranteeing a high-accuracy glucose analysis in various raw noninvasive biofluids. We also evaluated the potential utility of the universal fully integrated nanoelectronic system for noninvasive glucose management in healthy and diabetic subjects with the assistance of the proposed volatility-derived blood glucose concentration-free protocol. Although we focus on raw noninvasive biofluid glucose analysis in this work, the universal fully integrated nanoelectronic system may readily realize accurate monitoring of various biomolecules in raw noninvasive biofluids by introducing corresponding bioreceptors.

Fully integrated nanodevices that allow the complete functional implementation without an external accessory or equipment are deemed to be one of the most ideal and ultimate goals for modern nanodevice design and construction. In this work, we demonstrate the first example of a bendable biofuel cell (BFC)-based fully integrated biomedical nanodevice with simple, palm-sized, easy-to-carry, pump-free, cost-saving, and easy-to-use features for the point-of-care (POC) diagnosis of scurvy from a single drop of untreated human serum (down to 0.2 μL) by integrating a bendable and disposable vitamin C/air microfluidic BFC (micro-BFC) (named iezCard) for self-powered vitamin C biosensing with a custom mini digital LED voltmeter (named iezBox) for signal processing and transmission, along with a ″built-in″ biocomputing BUFFER gate for intelligent diagnosis. Under the simplicity- and practicability-oriented idea, a cost-effective strategy (e.g., biomass-derived hierarchical micro–mesoporous carbon aerogels, screen-printed technique, a single piece of Kimwipes paper, LED display, and universal components) was implemented for nanodevice design rather than any top-end or pricey method (e.g., photolithography/electron-beam evaporation, peristaltic pump, wireless system, and 3D printing technique), which enormously reduces the cost of feedstock down to ∼USD 2.55 per integrated kit including a disposal iezCard (∼USD 0.08 per test) and a reusable iezBox (∼USD 2.47 for large-scale tests). These distinctive and attractive features allow such a fully integrated biomedical nanodevice to fully satisfy the basic requirements for POC diagnosis of scurvy from a single drop of raw human serum and make it particularly appropriate for resource-poor settings, where there is a lack of medical facilities, funds, and qualified personnel.

Fully integrated wearable electronics that combine the extraordinary feature of incessant and on‐body operation with the distinctive external equipment‐free trait are the ultimate goal of modern wearables. Epidermal sweat and wound exudate, as two noninvasively accessible biofluids on/surrounding the skin, reflect underlying health conditions. However, the design of universal wearable sensors with the bifunctional capability to monitor both epidermal secretions is still a challenge. Here, a single bifunctional fully integrated wearable tracker for wirelessly, simultaneously, and dynamically in situ measuring multiple epidermal sweat or wound exudate biomarkers is propos. Considering the electrolytes (e.g., Na+, K+, and H+) and metabolites (e.g., uric acid (UA)) levels in sweat or wound exudate may correlate with health or wound conditions, the dynamic and skin‐on tracking of the biomarkers of Na+, K+, pH, and UA levels in sweat under subjects’ exercise and in wound exudate during subjects’ wound healing are performed through the seamless integration of microfluidic, sensing, and electronic modules. Its applicability is evaluated for noninvasive hyperuricemia management in hyperuricemia/healthy subjects through a purine‐rich intake test and for wound management in subjects’ infected wounds through a control medical treatment.

Wearable biofuel cells (BFCs) technologies have the potential to address the challenge of on‐body energy supply of wearable electronics. However, previous wearable BFCs primarily focus on “worn‐on‐skin” sweat ones, which can hardly directly generate steady and nonintermittent electricity under certain but almost ineluctable wearable circumstances (e.g., intermittent sweating, perspiration biofuel concentration fluctuation, and dynamic contact between wearable BFCs and epidermal sweat). Here, in an alternative “worn‐close to‐skin” manner, the first example of a flexible BFC‐in‐a‐tube (named iezTube) as an entirely self‐contained wearable BFC (ESW‐BFC) for wearable energy generation by integrating a single‐layer fluff pulp (FP)‐based microfluidic module for the efficient sampling/utilization of biofuel fluids and the steady contact between biofuel fluids and wearable BFC with a flexible nano‐engineered BFC‐based BFC module for real‐time bio‐energy generation, along with an air‐breathing module that is based on a breathable and waterproof non‐woven tapes covered centrifuge tube‐based for continuous oxidizer supply, is reported. Through the seamless system integration, effective series‐connection pattern, and diverse readily accessible biofuel fluids pre‐collection, the iezTube demonstrates an exceptional capability to steadily and nonintermittently power wearable electronics under some certain but nearly ineluctable wearable circumstances and holds considerable and inimitable prospects as an ESW‐BFC for wearable electronics.