Highly Sensitive Detection of UV Radiation Using a Uranium Coordination Polymer

The accurate detection
of UV radiation is required in a wide range of chemical industries
and environmental or biological related applications. Conventional
methods taking advantage of semiconductor photodetectors suffer from
several drawbacks such as sophisticated synthesis and manufacturing
procedure, not being able to measure the accumulated UV dosage as
well as high defect density in the material. Searching for new strategies
or materials serving as precise UV dosage sensor with extremely low
detection limit is still highly desirable. In this work, a radiation
resistant uranium coordination polymer [UO2(L)­(DMF)] (L
= 5-nitroisophthalic acid, DMF = N,N-dimethylformamide, denoted as compound 1) was successfully
synthesized through mild solvothermal method and investigated as a
unique UV probe with the detection limit of 2.4 × 10–7 J. On the basis of the UV dosage dependent luminescence spectra,
EPR analysis, single crystal structure investigation, and the DFT
calculation, the UV-induced radical quenching mechanism was confirmed.
Importantly, the generated radicals are of significant stability which
offers the opportunity for measuring the accumulated UV radiation
dosage. Furthermore, the powder material of compound 1 was further upgraded into membrane material without loss in luminescence
intensity to investigate the real application potentials. To the best
of our knowledge, compound 1 represents the most sensitive
coordination polymer based UV dosage probe reported to date.