Tailoring kinetic energy barriers in hollow bimetallic sulfides via amorphous engineering for advanced non-invasive...

The advent of non-invasive saliva glucose sensing promises to revolutionize diabetic care paradigms, yet the critical challenge lies in engineering ultra-sensitive sensing materials. Herein, we synthesized amorphous double-shelled hollow bimetallic transition metal sulfides (ADH-BTMSs) via coordinated etching and precipitation (CEP) methods, where Ni/Co stoichiometric modulation enabled precise amorphous engineering. The resulting electrocatalyst, with a Ni/Co molar ratio of 1:1, featured high electrocatalytic activities, fast electron/ion transfer, and optimized reaction kinetics. The density functional theory (DFT) calculations and experiments corroborated that tuned amorphous nature for bimetallic sulfides lowered energy barriers for glucose evolution, particularly for the rate-limiting step and dissociation. Serving as non-invasive salivary sensing platforms, the targeted electrocatalyst demonstrated remarkable sensing characteristics, with excellent sensitivities up to 3728.6 μA mM^-1 cm², low detection limit (50 nM), wide linear range of 0.1-1074.1 μM, and ideal stability. Moreover, the developed portable non-invasive sensing sensors efficiently carried out the analysis of human saliva glucose concentration, the relevant results of which are consistent with those of commercial invasive blood glucose sensors. The research indicates that implementing amorphous engineering on bimetallic sulfides holds immense appeal for the advancement of non-invasive salivary sensing analytics.