Zirconium metal organic framework based opto-electrochemical sensor for nitrofurazone detection

The manuscript presents a zirconium metal–organic framework (Zr-MOF or UiO-66-NH2) based efficient sensing system to detect nitrofurazone (NFZ) antibiotic, by employing electrochemical-optical dual detection technique. The Zr-MOF was synthesized by solvothermal method and the success of synthesis was confirmed by using analytical techniques of characterization. For electrochemical determination of NFZ, electrodeposited gold nanoparticles supported zirconium metal–organic framework modified screen-printed electrode (AuNPs/UiO-66-NH2/SPCE) was used. As prepared electrochemical sensing platform showed a wide linear concentration range of 1x10−8 to 5x10−5 mol/L for NFZ. For fluorometric measurements, synthesized UiO-66-NH2 was employed under optimized conditions, and a turn-off behavior of NFZ towards UiO-66-NH2 was observed from a range of concentration 1x10−8 to 4.5x10−5 mol/L of NFZ. The proposed opto-electrochemical sensor attained low detection limit in nM range, showed selective behavior in presence of other antibiotics, and gave a reproducible signal with the RSD value less than 2.5% (n = 5). The prepared sensor was tested to detect NFZ in lake water samples and the results indicated good percentage recovery in the range 97.70–98.40 and 93.30–97.84%, for electrochemical and optical methods, respectively.