I-motif sensor for the fluorometric detection of Monkeypox

In this study, we developed an isothermal fluorometric diagnostic method for DNA virus-generating disorders such as Mpox. Our results showed that the release of a large number of protons during multiplex-LAMP markedly lowered the pH level, which transformed the retinoblastoma (Rb) linear ssDNA into i-motifs. Consequently, thiazole orange (TO; a fluorometric probe sensitive to the i-motif) boosted the signal-on fluorescence because of its ability to bind selectively to i-motifs. This multiplex-LAMP/i-motif-TO system enabled simultaneous detection aimed at numerous potential targets with remarkable sensitivity (1.47 pg per mL) and efficiency (30 minutes). Our method is expected to enable DNA-virus-related diseases to be efficiently and accurately assessed.