Liposome-encapsulated aggregation-induced emission fluorogen assisted with portable smartphone for dynamically on-site imaging of residual tetracycline

Abstract

Reliable on-site monitoring of antibiotic residue is critical to establish the efficient pollution early-warning mechanism for ensuring food safety and environmental health. Herein, we reported the engineering of liposome-encapsulated aggregation-induced emission fluorogen into the portable smartphone for achieving the visual on-site detection of residual tetracycline (TC). Through nanoprecipitation, the aggregation-induced emission fluorogen (AIEgen) tetraphenylethene (TPE) was encapsulated into an amphiphilic phospholipid polymer, affording a scaffold to assemble Eu3+ for forming Eu3+-functionalized liposome-based AIEgen (Eu3+@AIEgen) with bright blue fluorescence at ~456 nm. Upon assistance of citrate, TC was capable of triggering the remarkable fluorescence color change from bright blue (~456 nm) to pink owing to the new red fluorescence emission appeared at ~611 nm, thereby emerging a significant dual-emission for ratiometric response. As expected, an ingenious citrate-assisted Eu3+@AIEgen liposome-based smartphone was proposed to precisely on-site report the residual levels of TC in real sample among the linear range of 0.0961–10.0 μM. Furthermore, this portable sensor exhibited a high sensitivity attributable to the low detection limit of 28.83 nM together with a fast response kinetics of 2.0 min for TC, agreeing well with the demands of on-site assay. This study showed the promising potential for utilizing AIEgen liposome to develop a new category of portable sensors for the point-of-care detection of antibiotic residue in complicated food and environment-related matrixes, which might open a novel way to establish efficient pollution early-warning mechanism for safeguarding public health.