Selective and sensitive fluorescence “turn-on” detection of 4-thiouridine in nucleic acids<i>via</i>oxidative amination

Abstract

A fluorescence "turn-on" method for digestion-free analysis of 4-thiouridine (s4U) in nucleic acids was developed in this work based on the oxidative amination of s4U by fluoresceinamine (FAM-NH2) and periodate (IO4-). It was 125-fold more sensitive for s4U detection than the traditional UV330 absorption method, and showed excellent selectivity to s4U over 2-thiouridine (s2U) analogues and biological thiols.