Development of Small-sized Lysine Enzyme Sensor for Clinical Use

Abstract

We have developed an electrochemical biosensor to measure the lysine concentration in blood. The lysine biosensor has a simple design and can complete measurements of a 5 μL sample in 2 min, enabling rapid measurement in clinical practice. The target molecules are catalyzed by enzymes encapsulated in carboxymethyl cellulose on the working electrodes to produce potassium ferrocyanide as an electron mediator that is detected on the electrodes amperometrically. In a clinical application, the sensor was used to measure blood lysine concentrations in 47 pediatric surgical patients. The results showed that the lysine level was correlated with the transthyretin level, a conventional nutritional indicator, confirming its usefulness for nutritional assessment. This sensor can be used for postoperative nutritional management and treatment of rare diseases such as lysinuric protein intolerance. The platform also has a versatile design for the detection of other amino acids in addition to lysine.

Immobilization of Liposomes into Porous Anodized Aluminum Oxide and Intact and On-demand Release by Ultrasonic Irradiation

“…3,4 In addition, these synthetic liposomes and extracellular vesicles have attracted much attention as useful careers of a diversity of cargos ranged from small molecules to large biomolecules for the construction of drug delivery systems. 5,6 Meanwhile, solid nano-and meso-porous materials hold great premise as platforms for integration of various molecules including proteins 7,8,9,10,11,12 , nucleic acids 13,14 and small molecules. 15,16 The immobilization and controlled release of these molecules were achieved on the solid porous materials, which paves the way for the development of separation techniques, 10,9 biosensors 11,12 containers, 13,8 and drug delivery systems.…”

Development of Microdrip Enzyme Device Using Carbon-Coated Porous Silica Spheres

“…This requires comprehensive development of electrode materials, mediators, and composition of electrodes. , The most successful enzymatic sensor in point-of-care (POC) devices is the glucose sensor. , Various types of sensors have been proposed for glucose sensors. , However, there are almost no reports of practical application of POC devices other than glucose sensors. We previously demonstrated a prototype POC device with detection limits, reproducibility, and stability for quantifying lysine concentration in samples . In that study, we used industry standard, rare metals such as gold or platinum as the working electrode.…”

“…We previously demonstrated a prototype POC device with detection limits, reproducibility, and stability for quantifying lysine concentration in samples. 7 In that study, we used industry standard, rare metals such as gold or platinum as the working electrode. In consideration of future commercial positioning of the device, where design flexibility, production cost, and material stability are high priorities, we propose exploring carbon-based electrodes as low-cost alternative materials to address the cost and production impact of the sensor system.…”

“…This requires comprehensive development of electrode materials, mediators, and composition of electrodes. 6,7 The most successful enzymatic sensor in point-of-care (POC) devices is the glucose sensor. 8,9 Various types of sensors have been proposed for glucose sensors.…”

“…However, these biosensors have the interference of electroactive substances with the enzyme due to the high potential required for detection. − With the sensitivity highly dependent on the integrity of the enzyme structure, improving the enzyme stability is critical. This requires comprehensive development of electrode materials, mediators, and composition of electrodes. , The most successful enzymatic sensor in point-of-care (POC) devices is the glucose sensor. , Various types of sensors have been proposed for glucose sensors. , However, there are almost no reports of practical application of POC devices other than glucose sensors. We previously demonstrated a prototype POC device with detection limits, reproducibility, and stability for quantifying lysine concentration in samples .…”