Ultra-convenient and rapid synthesis of FeAg MOGs for sensitive test strips detection of dopamine in human serum

Metal-organic gels (MOGs) represent the unique category of metal-organic materials, notably distinguished by their expansive specific surface area, highly porous structural frameworks, and readily accessible metallic active sites. This investigation involved the synthesis of FeAg MOGs at ambient temperature using 1,3,5-phenyltricarboxylic acid (H₃BTC) as a ligand through a simple, one-step method. The resultant FeAg MOGs exhibit excellent oxidase activity, capable of oxidizing 3,3',5,5'-tetramethylbenzidine (TMB) into blue oxTMB. In experimental studies we have discovered that dopamine (DA) exhibits the specific inhibitory effect on the colorimetric response of the FeAg MOGs-TMB system. Based on this a simple, rapid, and sensitive colorimetric method for the selective detection of DA was developed. This methodology possesses a ultra-wide detection range (linear range: 2 μM to 5000 μM) with a detection limit (LOD, S/N = 3) of 1.324 μM. It has proven effective and has been utilized successfully for the quantitative testing of DA in samples of human serum. Furthermore, a test paper has been designed to visually determine DA concentration within a range 2 μM to 1000 μM. The study demonstrates the enormous potential of MOGs for application in the field of colorimetric analysis.