Integrated molybdenum single atom array sensors with multichannels for nitrite detection in foods

Nitrite (NO₂^-) is present in a variety of foods, but the excessive intake of NO₂^- can indirectly lead to carcinogenic, teratogenic, mutagenicity and other risks to the human body. Therefore, the detection of NO₂^- is crucial for maintaining human health. In this study, an integrated array sensor for NO₂^- detection is developed based on molybdenum single atom material (IMS_Mo-SAC) using high-resolution electrohydrodynamic (EHD) printing technology. The sensor comprises three components: a printed electrode array, multichannels designed on polydimethylsiloxane (PDMS) and an electronic signal process device with bluetooth. By utilizing Mo-SAC to facilitate electron transfer during the redox reaction, rapid and efficient detection of NO₂^- can be achieved. The sensor has a wide linear range of 0.1 μM-107.8 mM, a low detection limit of 33 nM and a high sensitivity of 0.637 mA^-1mM^-1 cm^-2. Furthermore, employing this portable array sensor allows simultaneously measurements of NO₂^- concentrations in six different foods samples with acceptable recovery rates. This array sensor holds great potential for detecting of small molecules in various fields.