A Wearable Electrochemical Biosensor Utilizing Functionalized Ti₃C₂T_x MXene for the Real-Time Monitoring of Uric Acid Metabolite

Abstract

Wearable, noninvasive sensors enable the continuous monitoring of metabolites in sweat and provide clinical information related to an individual's health and disease states. Uric acid (UA) is a key indicator highly associated with gout, hyperuricaemia, hypertension, kidney disease, and Lesch−Nyhan syndrome. However, the detection of UA levels typically relies on invasive blood tests. Therefore, developing a wearable device for noninvasive monitoring of UA concentrations in sweat could facilitate realtime personalized disease prevention. Here, we introduce 1,3,6,8-pyrene tetrasulfonic acid sodium salt (PyTS) as a bifunctional molecule functionalized with Ti 3 C 2 T x via π−π conjugation to design nonenzymatic wearable sensors for sensitive and selective detection of UA concentration in human sweat. PyTS@ Ti 3 C 2 T x provides many oxidation−reduction active groups to enhance the electrocatalytic ability of the UA oxidation reaction. The PyTS@Ti 3 C 2 T x -based electrochemical sensor demonstrates highly sensitive detection of UA in the concentration range of 5 μM−100 μM, exhibiting a lower detection limit of 0.48 μM compared to the uricase-based sensor (0.84 μM). In volunteers, the PyTS@Ti 3 C 2 T x -based wearable sensor is integrated with flexible microfluidic sweat sampling and wireless electronics to enable real-time monitoring of UA levels during aerobic exercise. Simultaneously, it allows for comparison of blood UA levels via a commercial UA analyzer. Herein, this study provides a promising electrocatalyst strategy for nonenzymatic electrochemical UA sensor, enabling noninvasive real-time monitoring of UA levels in human sweat and personalized disease prevention.

Toward the Next Generation Human–Machine Interaction: Headworn Wearable Devices

“…Additionally, it holds potential in the treatment of certain human bodily ailments. − Common forms of equipment include headbands, necklaces, glasses, vests, clothes, belts, watches, bracelets, anklets, and so on. Among them, watches and bracelets are the most common and mostly used to monitor health conditions. − Furthermore, a limited number of wearable bracelets and glasses have achieved the capability to monitor blood pressure levels and body fluid composition through the utilization of optical sensors. − The data include physiological parameters collected by wearable devices such as blood pressure, ECG, heart rate, breathing, exercise steps, calories, blood, urine, tear, hemoglobin, white blood cell, and other biochemical data; photos of various parts of the body; and portable B-ultrasonography image data. Moreover, the physiological level should be monitored based on sensors. − The application prospects of wearable devices are very broad, but relatively there are few studies on wearable head devices which have focused on eyes, headwear, and earwear.…”

Self-powered sensing platform for monitoring uric acid in sweat using cobalt nanocrystal-graphene quantum dot-Ti3C2TX monolithic film electrode with excellent supercapacitor and sensing behavior

“…The nanomaterials used in electrochemical detection of uric acid mainly include metal nanocrystal such as Fe [10], metal oxide such as Ta 2 O 5 [11], 2D material such as graphene [12] and MXene [13]. Metal nanocrystal has a high conductivity, but it is prone to combine with electroactive analyte and produce a serious memory effect unless noble metal nanocrystal.…”

“…The resultant composite has a signi cantly improved conductivity, but a huge energy barrier between carbon material and metal oxide restricts a high-speed electron transfer in the interface. As a newly emerged 2D material, Ti 3 C 2 T X was investigated to electrochemical detection of uric acid coupled with TiO 2 [13]. Since the production of heterojunction at TiO 2 /Ti 3 C 2 T X interface improves the catalytic activity of TiO 2 towards oxidation of uric acid, the electrochemical sensor based on TiO 2 / Ti 3 C 2 T X shows a low detection limit of 0.78 nM.…”

Flexible Wearable Electrochemical Sensors Based on AuNR/PEDOT:PSS for Simultaneous Monitoring of Levodopa and Uric Acid in Sweat

“…Sweat contains various biomarkers, such as biological molecules uric acid (UA) and ascorbic acid (AA); electrolytes Na + , K + , and Cl – ; and metabolites glucose and lactic acid (LA). Unlike the invasive detection of biomarkers in blood, biomarker detection from sweat is a noninvasive and continuous process. , Rapid advancement in wearable flexible sensor technology in recent years has significantly facilitated research on sweat analysis for personalized healthcare. − ,− Glucose in sweat has been monitored for the treatment and management of diabetes. − Sweat–UA detection sensors have been used for gout management and to assess cardiovascular and kidney diseases. , Sensors for the noninvasive sweat-based tracking of levodopa (LD) have been developed to monitor the oral administration of LD tablets in Parkinson’s disease (PD) patients . Sweat contains hundreds of trackable biomarkers; therefore, the development of wearable electrochemical sensors for simultaneous multiparameter detection could facilitate the accurate treatment and management of several diseases. , However, most wearable electrochemical sensors developed to date are enzymatic sensors with substrate selectivity. − As an enzyme catalyzes only a specific biomarker, enzymatic sensors for multiparameter detection require a large area for immobilizing various enzymes; therefore, the fabrication of such sensors is complex.…”