Ultra-pH-responsive split i-motif based aptamer anchoring strategy for specific activatable imaging of acidic tumor microenvironment.

A non-blocking split i-motif based aptamer anchoring strategy was developed as a general platform for sensing weakly acidic tumor microenvironment. By rationally tuning the response range to pH 7.0-6.4 and adjusting aptamer types, the strategy achieved specific, pHe-activated imaging of different cancers in vitro and in vivo.