DNA and RhoB-functionalized metal–organic frameworks for the sensitive fluorescent detection of liquid alcohols

The detection of alcohols is needed urgently in many fields such as biomedicine, food industry, agriculture, environmental analysis, and chemical fuels. It is of great importance to develop an uncomplicated, rapid and highly-sensitive biosensor for the detection of liquid alcohols. Herein, we proposed a fluorescent biosensor to detect the liquid alcohols by employing metal–organic frameworks (MOFs) functionalized with DNA and Rhodamine B (RhoB). Porous MOF nanoparticles (UiO-66) were covalently modified with DNA, which acted as a gatekeeper to cap MOFs. Fluorescent dyes (RhoB) were loaded into DNA-modified porous MOF nanoparticles, in which DNA can help to keep RhoB inside the pores. It's found that alcohols can trigger the specific release of RhoB from MOFs with DNA and RhoB, which was utilized to detect liquid alcohols sensitively by measuring the fluorescent intensity of released RhoB. The results demonstrated that the fluorescent intensity of released RhoB was proportional to the concentration of target alcohols. Three kinds of liquid alcohols (methanol, ethanol, and isopropanol) were detected with detection limits down to 0.05%, 0.005%, and 0.005%, respectively. In addition, the selectivity and stability of this fluorescent biosensor have also been evaluated. This sensing strategy here successfully performed the liquid alcohols detection with excellent performance, which has great potential to promote the development of portable liquid alcohols detection equipments.