A near-infrared fluorescent probe to superoxide anion with second-level response time for in situ evaluating interstitial cystitis

Reliably determining the physiological level of superoxide anion (O2·-) in bladder is vital for clinical diagnosis and evaluation of interstitial cystitis (IC), but it yet remains as a daunting challenge. In this work, we constructed a new type of fluorescent probe (XM-TBS) capable of detecting O2·- with high sensitivity and superb recognition specificity against potential interfering species. XM-TBS presents fluorescence response to O2·- species within 6 s, an unprecedented response agility to O2·- species as compared to the counterpart probes developed to date. The unique electronic configuration of XM-TBS molecule makes its active site more vulnerable to O2·--mediated nucleophilic attack, which is expected to enable high recognition rate to O2·-. In light of the advantages of XM-TBS regarding second-level response time, superb recognition selectivity and the ability of fluorescence imaging for revealing the upregulated O2·- in bladder of model mice with IC, we envision it possesses great potential in diagnosis of O2·--associated IC in practical applications.