Cationic poly(fluorene-co-phenylene) derivative (PFPNMe3
+
) forms a supramolecular complex with cucurbit[7]uril (CB[7]),
which could be reversibly disassembled by amantadine (AD) to release
PFP-NMe3
+ due to the formation of more stable CB[7]/AD complex.
The cationic PFP-NMe3
+ is an amphiphilic structure and could bind to
negatively charged membrane of pathogen by multivalent interactions.
Upon the formation of PFP-NMe3
+
/CB[7] complex, the CB[7] could
bury the side-chain alkyl groups and decreases the hydrophobic
interactions of PFP-NMe3
+ on the surface of pathogens; thus, PFPNMe3
+ exhibits different interaction modes with pathogens before and
after assembly with CB[7]. The PFP-NMe3
+
/CB[7] supramolecular
complex could be explored as optical sensor for simple, rapid, and in situ
detection and discrimination of multiple pathogens by taking advantage
of optical signal changes of PFP-NMe3
+
/CB[7] complex before and after
disassembly by AD on the pathogen surfaces. The new sensor can realize in situ detection and identification of Gram-negative
bacteria (E. coli, P. aeruginosa), Gram-positive bacteria (B. subtilis, S. aureus, E. faecalis), and the fungi (C. albicans, S. cerecisiae)
and can also discriminate different strains of the same species. Blend samples of these pathogens could be identified successfully
as well. In comparison with conventional blood culture-based pathogen assay methods that require at least for 24 h, the PFPNMe3
+
/CB[7] complex only needs 2 h (including pathogen culture, pathogen harvest by centrifuging, and optical assay
procedures) to stratify diverse pathogen types and also does not require specific biomarkers or cell labeling