A Zn‐based metal–organic framework for the irreversible determination of trace biomarkers of styrene and ethylbenzene in urine.

Phenylglyoxylic acid (PGA), as a urine metabolite of ethylbenzene and styrene (EB/S), can effectively represent the level of EB/S ingested by the human body through oral inhalation and skin absorption. Compared with measuring EB/S levels directly in the environment, detecting the level of PGA in urine has the advantages of high specificity and noninvasive sampling. In this paper, a metal–organic framework (MOF)‐based sensor Zn‐PBA = ({[Zn(PBA)·H2O]·2H2O}n, H2PBA = 4‐(5‐pyridinyl)‐1,3 benzoic acid) for trace detection of PGA was designed and synthesized by a solvothermal method. Zn‐PBA could detect the level of PGA in normal human physiological urine environment (pH range from 5.5 to 7.5) and has the characteristics of high selectivity and sensitivity, rapid response (<210 s), low limit of detection (LOD = 1.96 × 10−6 M), and so forth. The irreversible sensing of PGA proves that PGA caused the structural collapse of Zn‐PBA. This paper provides a specific sensor for detecting trace PGA level for evaluating the EB/S content intake by the human body. [ABSTRACT FROM AUTHOR]