Sensitive humidity sensor based on moisture-driven energy generation

The emergence of novel self-powered humidity sensors has attracted considerable attention in the fields of smart electronic devices and personal healthcare.Herein,self-powered humidity sensors have been fabricated using a moisture-driven energy generation(MEG)device based on asymmetric tubular graphitic carbon nitride(g-CN)films prepared on anodized aluminum(AAO)template.At a relative humidity(RH)of 96%,the MEG device can provide an open-circuit voltage of 0.47 V and a short-circuit current of 3.51μA,with a maximum output power of 0.08μW.With inherent self-powered ability and humidity response via current variation,an extraordinary response of 1.78×106%(41%-96%RH)can be gained from the MEG device.The possible power generation mechanism is that g-CN/AAO heterostructure can form ion gradient and diffusion under the action of moisture to convert chemical potential into electrical potential,evoking a connaturally sensitive response to humidity.Self-powered respiration monitoring device based on the sensor is designed to monitor human movement(sitting,warming up,and running)and sleep status(normal,snoring,and apnea),maintaining excellent stability during cumulative 12-h respiration monitoring.This self-powered humidity sensing technology has promising potential for extensive integration into smart electronic and round-the-clock health monitoring devices.

Near-infrared chemiluminescent carbon nanogels for oncology imaging and therapy

Carbon nanogels(CNGs)with dual ability of reactive oxygen species(ROS)imaging and photodynamic therapy have been designed with selfassembled chemiluminescent carbonized polymer dots(CPDs).With efficient deep-red/near-infrared chemiluminescence(CL)emission and distinctive photodynamic capacity,the H2O2-driven chemiluminescent CNGs are further designed by assembling the polymeric conjugate and CL donors,enabling an in vitro and in vivo ROS bioimaging capability in animal inflammation models and a high-performance therapy for xenograft tumors.Mechanistically,ROS generated in inflammatory sites or tumor microenvironment can trigger the chemically initiated electron exchange luminescence in the chemical reaction of peroxalate and H2O2,enabling in vivo CL imaging.Meanwhile,part of the excited-state electrons will transfer to the ambient H2O or dissolved oxygen and in turn lead to the type I and type II photochemical ROS production of hydroxyl radicals or singlet oxygen,endowing the apoptosis of tumor cells and thus enabling cancer therapy.These results open up a new avenue for the design of multifunctional nanomaterials for bioimaging and antienoplastic agents.