Designing a smart fluorescence chemosensor within the tailored channel of mesoporous material for sensitively monitoring toxic heavy metal ions Pb(II)

A highly selective and sensitive fluorescence chemosensor for Pb2+ ion has been developed by covalent coupling of Bis-schiff base PMBA chromophore within the tailored channel of mesoporous material SBA-15. The chloropropyl-group functionalized mesoporous SBA-15 that was prepared in one-pot synthesis can serve as a suitable sensor scaffold because it can supply the especially flexible and electron-rich inner surface to avoid the self-quenching of fluorescent chromophore, and TEM. Low-angle XRD confirm that the ordered pore structure of mesoporous material is well maintained in the functional composite. This PMBA-SBA chemosensor works well over a wide concentration range of Pb2+, 2–50 μM, with immediate response, and its rapid response is resulted from the straight channel of SBA-15 that facilitates the access of analyte. The excellent sensitivity of PMBA-SBA with the detection limit of 0.5 nM (0.1 ppb) is owing to the optimum steric configuration of fluorescent molecules within the flexible nanochannel of mesoporous chemosensor. High sensitivity and immediate signal response of PMBA-SBA chemosensor enable it to a promising candidate for practical analysis of Pb2+ ion.