The present invention provides a composition for acetone detection and a process of preparation thereof. The composition comprises γ-ferric oxide (γ-Fe2O3), antimony (Sb) salt, and platinum (Pt). The sensor fabricated using the said composition is selective to low concentration of breath acetone, the biomarker of diabetes, in presence of high amount of moisture normally present in breath. Such semiconductor sensors for diabetes monitoring are inexpensive, rugged, patient-friendly and on the top, non-invasive.