Highly stable perovskite nanocrystal based fluorescent aptasensor for sensitive detection of MtbMS and Mtb H37Rv

The accurate and rapid detection of Mycobacterium tuberculosis ( M . tuberculosis ) is essential for the effective treatment of tuberculosis. In this work, perovskite/silica nanocomposites CsPbBr 3 @MSNs-PbBrOH (DP-CPB) were synthesized via a dual in situ-coating strategy, encapsulating CsPbBr 3 nanocrystals with mesoporous silica and PbBrOH. The resulting nanocomposites exhibited excellent stability in physiological media. The nanocomposites’ surface was conjugated with the MS10-Trunc aptamer specific for Mtb malate synthase ( MtbMS ). Leveraging the aptamer’s high affinity, we developed two fluorescent aptasensors: one based on a 96-well plate for MtbMS detection, and another employing magnetic nanoparticles for the detection of Mtb bacterial strains ( Mtb H37Rv). The sensors demonstrate dynamic ranges of 50-750 nM for MtbMS and 10 2 -10⁷ CFU/mL for Mtb H37Rv, with low limits of detection (LOD) of 1.17 nM and 3 CFU/mL, respectively. The aptasensors possess the comprehensive advantages of the highly efficient photoluminescence of DP-CPB, high specificity, and fast detection of MtbMS and H37Rv. The aptasensor was successfully applied for the determination of Mtb H37Rv, revealing the vast potential of perovskites in biosensing.