Bimetallic-based food sensors for meat spoilage: Effects of the accepting metallic unit in Fe(II)CNM (M = Pt(II) or Au(I)) on device selectivity and sensitivity.

Technologies for monitoring meat spoilage are important to ensuring consumer safety. As dimethyl sulfide (DMS) is a reliable marker for meat freshness, sensitive and selective DMS sensors are of great interest. Herein, two trinuclear cyano-bridged bimetallic donor-acceptor ensembles, Fe(bpy)(CN)-[Pt(DMSO)Cl] (1) and Fe(bpy)(CN)-[AuCl], were synthesized, and corresponding solid-supported sensors were fabricated to determine the effect of the acceptor metal (M) on DMS detection. Changing M from Au to Pt improved the sensitivity and selectivity owing to changes in the relative thermodynamic stabilities of the complex and M-DMS adduct. When applied to real meat samples, 1 exhibited a linear spectroscopic response to DMS, even in the presence of interfering compounds, with a method detection limit of 1.0 ppm. The total bacteria count and gas chromatography-mass spectrometry results revealed that the spectroscopic signal generated by 1 correlated with the microbial growth level and DMS concentration during meat spoilage.