A facile fluorescence imprinted strategy based on boronic acid functionalized MOF and Mg/N-CDs for discrimination of transferrin: Expansion for boronic acid functionalized MOF application

In this research, we proposed a novel fluorescence imprinted sensor (FIS@MIP) for rapid and sensitive detection of transferrin (TrF) based on the boronic acid functionalized Zr-MOF (Zr-UiO-66-B(OH)2) and high fluorescence quantum yield of Mg/N co-doped carbon dots (Mg/N-CDs). The boronic acid moieties of Zr-UiO-66-B(OH)2 could significantly covalently bind TrF and load more Mg/N-CDs to avoid fluorescence quenching caused by self-aggregation of Mg/N-CDs. Additionally, Zr-UiO-66-B(OH)2 was prepared though linker fragmentation approach, which eliminated the complex post modification process and could provide sufficient boric acid groups. High luminescent and fluorescence quantum yield endowed Mg/N-CDs remarkable fluorescence response to TrF. Under the optimal conditions, the fluorescence intensity of FIS@MIP at 438 nm was quenched by Trf within 1 min. Based on specific recognition sites, a good linear relationship was obtained in the linear range of 0.1 µM–20 µM, and the low detection limit was determined as 0.067 µM. In order to explore portable detection application, a home-made device based on smartphone was designed for on-site detection of TrF with a detection limit of 0.38 µM. Significantly, this smartphone platform was successfully applied for detection of TrF in simulated actual samples (i.e., human urine and human serum) with satisfactory results, which provided a new promising strategy for on-site and sensitive discrimination of TrF in actual samples. This research will promote the development of the application of boronic-acid functionalized Zr-MOF in molecularly imprinted sensing of glycoproteins..