Controlled synthesis of -Fe2O3 nanocubes for gas-sensing applications: Feasibility of assessing crucian carp (Carassius auratus) freshness via trimethylamine levels

Trimethylamine (TMA) is an organic amine with strong pungent smell which is an indicator gas for evaluating fish freshness according to the international standard. In this work, as-synthesize alpha-Fe2O3 solid nanocubes (NCs), alpha-Fe2O3 nucleoshell NCs and alpha-Fe2O3 hollow NCs were used as sensing material to develop an outstanding TMA gas sensor. The response of the alpha-Fe2O3 hollow NCs sensors towards 20 ppm TMA at 230 celcius was 6.3. Meanwhile, these sensors showed exceptional response/recovery time, low limit of detection, great selectivity, and outstanding linear relationship. Furthermore, the analysis of gases released during the decomposition of Carassius auratus (0-10 days) was conducted, which demonstrated the assessment of TMA by alpha-Fe2O3 hollow NCs sensor can evaluate the freshness of Carassius auratus. Such a novel sensor signifies the outstanding application potential in efficient gas-sensing properties of TMA, which will make the tremendous contribution for Carassius auratus product evaluation in the future.