Self-Powered Diaper Sensor with Wireless Transmitter Powered by Paper-Based Biofuel Cell with Urine Glucose as Fuel

Abstract

A self-driven sensor that can detect urine and urine sugar and can be mounted on diapers is desirable to reduce the burden of long-term care. In this study, we created a paper-based glucose biofuel cell that can be mounted on diapers to detect urine sugar. Electrodes for biofuel cells were produced by printing MgO-templated porous carbon on which poly(glycidyl methacrylate) was modified using graft polymerization. A new bioanode was prepared through covalently modifying flavin-adenine-dinucleotide-dependent glucose dehydrogenase and azure A with pendant glycidyl groups of poly(glycidyl methacrylate). We prepared a cathode with covalently bonded bilirubin oxidase. Covalent bonding of enzymes and mediators to both the bioanode and biocathode suppressed elution and improved stability. The biofuel cell could achieve a maximum output density of 0.12 mW cm –2 , and by combining it with a wireless transmission device, the concentration of glucose sensed from the transmission frequency was in the range of 0–10 mM. The sensitivity of the sensor was estimated at 0.0030 ± 0.0002 Hz mmol –1 dm 3 . This device is expected to be a new urine-sugar detection device, composed only of organic materials with a low environmental load and it can be useful for detecting postprandial hyperglycemia.

Paper‐Based Wearable Ammonia Gas Sensor Using Organic–Inorganic Composite PEDOT:PSS with Iron(III) Compounds

“…It would also be possible to integrate the sensing element with an energy harvesting unit and a wireless transmitter for autonomous ammonia sensing in diapers. [ 46 ]…”

“…It would also be possible to integrate the sensing element with an energy harvesting unit and a wireless transmitter for autonomous ammonia sensing in diapers. [46] Table S2 (Supporting Information) summarizes the existing ammonia sensors that use organic conducting materials by categorizing them into three types: wired, wireless, and our wireless paper-based sensor. Comparison of the existing options suggests that almost no existing electrical ammonia sensors fit the requirements of the wearable format because of their poor sensing and wireless performance.…”

High-performance paper-based biocathode fabricated by screen-printing an improved mesoporous carbon ink and by oriented immobilization of bilirubin oxidase

“…Self-powered sensors do not require an energy source for the sensing device. Some examples of wearable biosensors and BFCs are integrated into the nose-pad of eyeglasses 23 , microfluidics fabricated from a soft material 24 , 25 , fabricated on thin flexible film 25 , 26 , tattoo-type 27 , textile-based 28 , 29 , and paper-based 30 – 32 .…”

“…Using MgOC as electrode material and lactate oxidase (LOx) as an enzyme, we achieved a power density of 0.113 mW cm −2 31 . Using GDH as an enzyme and improving immobilization, we achieved a power density of 0.12 mW cm −2 32 . These studies focused mainly on the anode performance.…”

Heat-transfer-printed Glucose Biosensor for Use in Diapers

“…(5)(6)(7)(8) This is intended for people who need nursing care, and aims at enabling the easy monitoring of urine glucose by allowing the direct evaluation of urine by simply wearing the specific device. In this context, a self-powered glucose biosensor system that can be integrated into diapers (i.e., wearable) to detect the urine glucose of diabetes patients was previously developed (9) by applying screen-printing technology using paper as a substrate. However, such diaper-mounted urine glucose sensors require preprocessing to mount the sensor stably in the diaper to integrate it into the diaper.…”