Tailoring Food Biopolymers into Biogels for Regenerative Wound Healing and Versatile Skin Bioelectronics

An increasing utilization of wound-related therapeutic materials and skin bioelectronics urges the development of multifunctional biogels for personal therapy and health management.Nevertheless,conventional dressings and skin bioelectronics with single function,mechanical mismatches,and impracticality severely limit their widespread applications in clinical.Herein,we explore a gelling mechanism,fabrication method,and functionalization for broadly applicable food biopolymers-based biogels that unite the challenging needs of elastic yet injectable wound dressing and skin bioelectronics in a single system.We combine our biogels with functional nanomaterials,such as cuttlefish ink nanoparticles and silver nanowires,to endow the biogels with reactive oxygen species scavenging capacity and electrical conductivity,and finally realized the improvement in diabetic wound microenvironment and the monitoring of electrophysiological signals on skin.This line of research work sheds light on preparing food biopolymers-based biogels with multifunctional integration of wound treatment and smart medical treatment.

Gas Sensors Based on Chemi?Resistive Hybrid Functional Nanomaterials

Chemi-resistive sensors based on hybrid functional materials are promising candidates for gas sensing with high responsivity,good selectivity,fast response/recovery,great stability/repeatability,room-working temperature,low cost,and easy-to-fabricate,for versatile applications.This progress report reviews the advantages and advances of these sensing structures compared with the single constituent,according to five main sensing forms:manipulating/constructing heterojunctions,catalytic reaction,charge transfer,charge carrier transport,molecular binding/sieving,and their combinations.Promises and challenges of the advances of each form are presented and discussed.Critical thinking and ideas regarding the orientation of the development of hybrid material-based gas sensor in the future are discussed.

An Organic Solvent-Assisted Intercalation and Collection (OAIC) for Ti_(3)C_(2)T_(x) MXene with Controllable Sizes and Improved Yield

A good method of synthesizing Ti_(3)C_(2)T_(x)(MXene)is critical for ensuring its success in practical applications,e.g.,electromagnetic interference shielding,electrochemical energy storage,catalysis,sensors,and biomedicine.The main concerns focus on the moderation of the approach,yield,and product quality.Herein,a modified approach,organic solvent-assisted intercalation and collection,was developed to prepare Ti_(3)C_(2)T_(x) flakes.The new approach simultaneously solves all the concerns,featuring a low requirement for facility(centrifugation speed<4000 rpm in whole process),gram-level preparation with remarkable yield(46.3%),a good electrical conductivity(8672 S cm^(−1)),an outstanding capacitive performance(352 F g^(−1)),and easy control over the dimension of Ti_(3)C_(2)T_(x) flakes(0.47–4.60μm^(2)).This approach not only gives a superb example for the synthesis of other MXene materials in laboratory,but sheds new light for the future mass production of Ti_(3)C_(2)T_(x) MXene.

Enhanced efficiency and stability in Sn-based perovskite solar cells with secondary crystallization growth

The conversion efficiencies reported for Tin(Sn)halide-based perovskite solar cells(PSCs)fall a large gap behind those of lead halide-based PSCs,mainly because of poor film quality of the former.Here we report an efficient strategy based on a simple secondary crystallization growth(SCG)technique to improve film quality for tin halide-based PSCs by applying a series of functional amine chlorides on the perovskite surface.They were discovered to enhance the film crystallinity and suppress the oxidation of Sn^(2+)remarkably,hence reduce trap state density and non-irradiative recombination in the absorber films.Furthermore,the SCG film holds the band levels matching better with carrier transport layers and herein favoring charge extraction at the device interfaces.Consequently,a champion device efficiency of 8.07% was achieved alo ng with significant enhancements in VOC and JSC,in contrast to 5.35% of the control device value.Moreover,the SCG film-based devices also exhibit superior stability comparing with the control one.This work explicitly paves a novel and general strategy for developing high performance lead-free PSCs.

Near index matching enables solid diffractive optical element fabrication via additive manufacturing

Diffractive optical elements(DOEs)have a wide range of applications in optics and photonics,thanks to their capability to perform complex wavefront shaping in a compact form.However,widespread applicability of DOEs is still limited,because existing fabrication methods are cumbersome and expensive.Here,we present a simple and cost-effective fabrication approach for solid,high-performance DOEs.The method is based on conjugating two nearly refractive index-matched solidifiable transparent materials.The index matching allows for extreme scaling up of the elements in the axial dimension,which enables simple fabrication of a template using commercially available 3D printing at tens-of-micrometer resolution.We demonstrated the approach by fabricating and using DOEs serving as microlens arrays,vortex plates,including for highly sensitive applications such as vector beam generation and super-resolution microscopy using MINSTED,and phase-masks for three-dimensional single-molecule localization microscopy.Beyond the advantage of making DOEs widely accessible by drastically simplifying their production,the method also overcomes difficulties faced by existing methods in fabricating highly complex elements,such as high-order vortex plates,and spectrum-encoding phase masks for microscopy.

Multifunctional interleaved geometric-phase dielectric metasurfaces

Shared-aperture technology for multifunctional planar systems,performing several simultaneous tasks,was first introduced in the field of radar antennas.In photonics,effective control of the electromagnetic response can be achieved by a geometric-phase mechanism implemented within a metasurface,enabling spin-controlled phase modulation.The synthesis of the shared-aperture and geometric-phase concepts facilitates the generation of multifunctional metasurfaces.Here shared-aperture geometric-phase metasurfaces were realized via the interleaving of sparse antenna sub-arrays,forming Si-based devices consisting of multiplexed geometric-phase profiles.We study the performance limitations of interleaved nanoantenna arrays by means of a Wigner phasespace distribution to establish the ultimate information capacity of a metasurface-based photonic system.Within these limitations,we present multifunctional spin-dependent dielectric metasurfaces,and demonstrate multiple-beam technology for optical rotation sensing.We also demonstrate the possibility of achieving complete real-time control and measurement of the fundamental,intrinsic properties of light,including frequency,polarization and orbital angular momentum.

Volatolomics in healthcare and its advanced detection technology

Various diseases increasingly challenge the health status and life quality of human beings.Volatolome emitted from patients has been considered as a potential family of markers,volatolomics,for diagnosis/screening.There are two fundamental issues of volatolomics in healthcare.On one hand,the solid relationship between the volatolome and specific diseases needs to be clarified and verified.On the other hand,effective methods should be explored for the precise detection of volatolome.Several comprehensive review articles had been published in this field.However,a timely and systematical summary and elaboration is still desired.In this review article,the research methodology of volatolomics in healthcare is critically considered and given out,at first.Then,the sets of volatolome according to specific diseases through different body sources and the analytical instruments for their identifications are systematically summarized.Thirdly,the advanced electronic nose and photonic nose technologies for volatile organic compounds(VOCs)detection are well introduced.The existed obstacles and future perspectives are deeply thought and discussed.This article could give a good guidance to researchers in this interdisciplinary field,not only understanding the cutting-edge detection technologies for doctors(medicinal background),but also making reference to clarify the choice of aimed VOCs during the sensor research for chemists,materials scientists,electronics engineers,etc.

Exhaled breath diagnostics of lung and gastric cancers in China using nanosensors

Dear Editor,Breath analysis is a promising diagnostic approach for various conditions[1,2].It is based on the identification of volatile organic compounds(VOCs)emitted in the breath,which creates a unique volatolomic signature[3].Owing to their characteristics,VOCs can be measured non-intrusively from the breath or other body sources[3,4].Several studies have shown the diagnostic potential for a variety of conditions based on VOC analysis[5-9].Malignant diseases,where early detection is crucial,are the main focus of VOC analysis,with lung cancer(LC)and gastric cancer(GC)being the most studied.LC and GC together were responsible for approximately 2.5 million deaths globally in 2018[10].The aim of VOC analysis of the breath using sensors is to identify a“VOC-print”comprising the total abundances and ratios of the compounds in the breath,giving an overall unique chemical pattern[11].

The marriage of sealant agent between structure transformable silk fibroin and traditional Chinese medicine for faster skin repair

Fast skin repair is critical for less infection, less pain and high quality of life, which is still limited with undesirable rehabilitation speed and side effects. Currently, laser-activated silk sealant agent without suture and gauze has been demonstrated promising for fast skin repair taking advantage of its structural transformation after heating. Nevertheless, more efficient healing effects and less side effects of laseractivated silk sealant agent remains challenging due to absence of suitable photo-thermal materials and robust/biomimetic protein materials. In this work, the marriage between silk protein and Rehmanniae radix preparata(a kind of the traditional Chinese herb) has been demonstrated as a novel and effective way to achieve an excellent healing effect for skin repair. The non-toxicity, high photothermal conversion efficiency and healing mechanism are systematically studied and proved. This new methodology might shed a new light for combining dark traditional Chinese medicine and silk fibroin for advanced wound healing technology.

Creating heralded hyper-entangled photons using Rydberg atoms

Entangled photon pairs are a fundamental component for testing the foundations of quantum mechanics,and for modern quantum technologies such as teleportation and secured communication.Current state-of-the-art sources are based on nonlinear processes that are limited in their efficiency and wavelength tunability.This motivates the exploration of physical mechanisms for entangled photon generation,with a special interest in mechanisms that can be heralded,preferably at telecommunications wavelengths.Here we present a mechanism for the generation of heralded entangled photons from Rydberg atom cavity quantum electrodynamics(cavity QED).We propose a scheme to demonstrate the mechanism and quantify its expected performance.The heralding of the process enables non-destructive detection of the photon pairs.The entangled photons are produced by exciting a rubidium atom to a Rydberg state,from where the atom decays via two-photon emission(TPE).A Rydberg blockade helps to excite a single Rydberg excitation while the input light field is more efficiently collectively absorbed by all the atoms.The TPE rate is significantly enhanced by a designed photonic cavity,whose many resonances also translate into high-dimensional entanglement.The resulting high-dimensionally entangled photons are entangled in more than one degree of freedom:in all of their spectral components,in addition to the polarization—forming a hyperentangled state,which is particularly interesting in high information capacity quantum communication.We characterize the photon comb states by analyzing the Hong-Ou-Mandel interference and propose proof-of-concept experiments.