Spinel Chromite MCr₂O₄ (M = Cu, Mg, Zn) Nanoparticle-Based Sensors for Trace Acetone Detection and Noninvasive Diabetes Diagnosis from Exhaled Breath

A noninvasive point-of-care diagnostic approach for detecting diabetes through exhaled breath analysis has been developed utilizing a highly sensitive spinel chromite-based sensor to detect acetone, a key biomarker in diabetic patients. Various spinel chromites, namely, MgCr₂O₄, CuCr₂O₄, and ZnCr₂O₄, were synthesized through the chemical route, and required characterizations were performed using relevant sophisticated tools. Our study reveals that MgCr₂O₄ exhibits outstanding sensing capabilities for trace acetone, surpassing other contenders in terms of response, selectivity, response and recovery times, repeatability, reproducibility, and long-term stability. The exceptional sensing performance of MgCr₂O₄ can be attributed to a synergistic combination of chromium’s bivalency, increased oxygen defects, and enhanced active surface area. The selectivity of the MgCr₂O₄ sensor toward acetone is largely governed by the maximum adsorption energy of acetone molecules compared to other interfering gases. The sensor’s efficacy in detecting diabetes was validated using both healthy subjects and simulated breath samples. Furthermore, its practical feasibility was successfully demonstrated through integration into a hand-held, Arduino-based breath analyzer prototype. This breakthrough may have far-reaching implications and poised to make a profound societal impact in the years to come.