Twisted Intramolecular Charge Transfer—Aggregation-Induced Emission Fluorogen with Polymer Encapsulation-Enhanced NearInfrared Emission for Bioimaging

Fluorescence probes with strong near-infrared(NIR)emission and water solubility are considered useful visualization tools for localization marking as well as investigating cell migration and transplantation.Here,we designed and synthesized a new donor–π–acceptor(D–π–A)fluorogen,2-(4-[(E)-4-(diphenylamino)styryl]phenyl)-3-(4′-[1,2,2-triphenylvinyl]-[1,1′-biphenyl]-4-yl)fumaronitrile(TB-TPE).TB-TPE exhibits twisted intramolecular charge transfer(TICT)and aggregation-induced emission(AIE)in the NIR region,with an emission peak at 714 nm and a fluorescence quantum yield(Qy)of 6.6%in the solid state.By encapsulating TB-TPE with polystyrene–polyethylene glycol(PS-PEG),watersoluble TB-TPE-PS-PEG nanoparticles(TP NPs)are fabricated,which display polymer encapsulationenhanced emission with a Qy of 46.5%due to the strong restriction effect on the TICT process and the destruction of H aggregation for TB-TPE by the polymer matrix.Au-coated Fe_(3)O_(4)(Fe_(3)O_(4)@Au)nanocrystals were then embedded in the TP NPs to form highly fluorescent TB-TPE-Fe_(3)O_(4)-Au-PS-PEG nanoparticles(TFAP NPs)with a Qy of 39.7%.Our demonstration of successful cellular imaging of TP NPs for Hep-G2 cells and multimodality imaging of TFAP NPs in mouse liver tumors indicates that polymer-encapsulated TB-TPE offers great prospects as a multifunctional fluorescence probe for bioimaging.

Wearable and flexible electrochemical sensors for sweat analysis:a review

Flexible wearable sweat sensors allow continuous,real-time,noninvasive detection of sweat analytes,provide insight into human physiology at the molecular level,and have received significant attention for their promising applications in personalized health monitoring.Electrochemical sensors are the best choice for wearable sweat sensors due to their high performance,low cost,miniaturization,and wide applicability.Recent developments in soft microfluidics,multiplexed biosensing,energy harvesting devices,and materials have advanced the compatibility of wearable electrochemical sweat-sensing platforms.In this review,we summarize the potential of sweat for medical detection and methods for sweat stimulation and collection.This paper provides an overview of the components of wearable sweat sensors and recent developments in materials and power supply technologies and highlights some typical sensing platforms for different types of analytes.Finally,the paper ends with a discussion of the challenges and a view of the prospective development of this exciting field.