A nanoscale Nd-based metal-organic framework electrochemical sensor for rapid detection of Rhodamine B

A novel neodymium-based metal-organic framework (Nd-MOF) {[Nd2(Hpdc)3(H2O)6]·3H2O}n (H3pdc ​= ​1H-pyrazole-3,5-dicarboxylic acid) was synthesized by a simple hydrothermal method and structurally characterized. By dropped onto glassy carbon electrodes (GCE), the prepared Nd-MOF was applied to construct an efficient electrochemical sensor for the rapid and reliable electrochemical detection of Rhodamine B (RhB). This proposed Nd-MOF/GCE sensor exhibited strong accumulation ability and high electrocatalytic activity for RhB. Electrochemical oxidation signal of RhB at the Nd-MOF/GCE was greatly enhanced as compared to that at the bare GCE. The effective factors such as pH of buffer solution, amount of Nd-MOF suspension and accumulation time were optimized for the quantitative detection of RhB. Under optimum conditions, the fabricated sensor showed two wide linear ranges of 0.08–2.0 and 2.0–40 ​μM with a low detection limit of 3.6 ​nM, which was ascribed to the advantages of Nd-MOF such as large specific surface area, multiple active sites, strong accumulation ability. Moreover, the developed Nd-MOF/GCE sensor displayed good selectivity and accuracy towards RhB detection in the actual samples. Thus, this simple and efficient approach for RhB detection has good prospective for application in environmental monitoring.