MXene@Pt nanocomposite and nanoporous carbon reinforced 3D graphene-based electrochemical multi-sensing patch for wearable sweat analysis

While skin-based electrochemical sensors patch for sweat analytes monitoring offers encouraging non-invasive biomarker monitoring, enzymatic biosensors pose several challenges, including low sensitivity and restricted detection range. An electrochemical epidermal patch based on the MXene@Pt nanocomposite anchoring electro-deposited platinum nanoparticles (PtNPs) functionalized laser-induced graphene (LIG) electrode (LIG/MXene@Pt/PtNPs) was newly developed for glucose, pH, and Na⁺ monitoring, while hybrid nanoporous carbon (HNPC) and Prussian blue (PB)-based lactate sensor was co-integrated for ultra-high lactate detection. Using simple, cost-effective, laser-engraved, and drop-casting techniques, were employed for four sensors fabrication in a patch. The developed glucose sensor demonstrated remarkable sensitivity (86.45 μAmM^-1cm⁻²) within the physiological sweat glucose concentration range (0–2 mM), while the HNPC-based lactate sensor showed a wide range (0–100 mM) detection capability. Moreover, the polyaniline-based pH sensor and Na⁺ ISE showed a near Nernstian sensitivity of −50.99 mV/pH over a pH range of 4–9 and 56.26 mV/decade respectively. Metal-like conductivity of Ti₃C₂T_x-MXene, high electrocatalytic properties of PtNPs and PB to H₂O₂, and enhanced electrochemical surface area of the HNPC-modified electrodes play a crucial role in realizing the high-sensitive glucose sensor and ultra-high detection of lactate sensors patch. Finally, the electrochemical multi-sensing patch was successfully employed to monitor the perspiration of a human volunteer during indoor stationary cycling.