Exploitation of 2D Mn-MOF nanosheets for developing rapid, sensitive, and selective sensor for determination of Mn(II) ions in food and biological samples

Herein, for the first time, a sensitive potentiometric sensor exploiting ultrathin two-dimensional nanosheets of Mn metal-organic framework (2D Mn-MOF-NSs) was prepared to determine Mn(II) ion content with accuracy and precision. Furthermore, a comparative study between the 2D Mn-MOF-NSs-based sensor and the 3D Mn-MOF-based one has been established which proves the superiority of 2D Mn-MOF-NSs as a sensing material achieving a slope of 29.50 mV decade^-1 within a wide linear range of 3.2 × 10^-6 - 1.0 × 10^-1 mol L^-1. The 2D Mn-MOF-NSs-based sensor can be applied for measuring the Mn(II) ion content rapidly (3 s) without being affected by the sample pH within a range from 2.0 to 8.5. Additionally, the sensor demonstrates high selectivity towards Mn(II) ion compared to numerous other cations. To prove the broad and effective application of the proposed sensor in diverse sectors, it was applied successfully for the determination of Mn(II) ions content in different food samples in addition to biological sample. Notably, the results attained by the sensor align well with those of the inductively coupled plasma (ICP) technique. Therefore, this article presented the first Mn(II) ion selective sensor based on ultrathin nanosheets of 2D Mn-MOF as a unique sensing material which can be regarded as one of the few sensors currently available for monitoring Mn(II) levels in various food samples in addition to biological samples with a high reliability and sensitivity.