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1IntroductionDirect electron transfer (DET) of heme protein has been aresearch focus becauseitnot only establishes adesirable model for fundamental study of proteins in biological systems,but also plays asignificant role in fabricating mediator-free bioelectrochemicald evices,s uch as the third generation biosensors [1],b iofuel cells [2],e nzymatic bioreactors [3] and biomedical devices [4].H emoglobin (Hb) is ak ind of utmost important heme protein in red cells.I t has aq uaternary structurec ontaining four polypeptide chains (globin chains)a nd one heme group bound to each globin chain [5,6].D ue to its known structurea nd commercial availability,H bi sc onsidered as an ideal model molecule for heme protein study.U nfortunately, DET between Hb and electrodes urface is generally difficult becauset he redox-active center is embedded in its protein shelld eeply [7] and enzyme usually losesi ts bioactivity on the bare electrode [8].T of acilitate DET and retain the bioactivity of immobilizede nzyme,b iocompatible materials have been used to immobilize Hb,s uch as surfactants [9],b iopolymers [10],h ydrogels [11],p olyelectrolytes [12] and nano-materials [13].Considerable attentions have been paid to nano-materials due to their remarkable advantages includingh igh conductivity,h igh catalytic efficiency and excellentb iocompatibility.T hey will present favorable microenvironment to keep the activity of immobilizedp roteins and consequently to fabricate eligible biosensors.F or exam-ple,A un anoparticles (Au-NPs) can offer an attractive platformf or enzyme immobilization not only because of its excellent conductivitya nd biocompatibility but also because of its facile and robust interaction with various biomolecules containing thiol and disulfideg roups [14,15].B esides,m agnetic nanoparticles are also strong candidates in al argev ariety of applications. They are ideal bimolecular immobilizingc arriers and they enable quick and efficient isolation or extraction of at arget molecule or substance by an externalm agnetic field [16].T he most widely studied superparamagneticn anoparticles are magnetite (Fe 3 O 4 ). However, naked Fe 3 O 4 nanoparticles are very sensitive to oxidation and pronet oa ggregate [17].O ne of the maina pproaches to overcome these limitations is to protect naked magnetic NPs with metals [18].Abstract:S table magneticn anocomposite of gold nanoparticles (Au-NPs) decoratingF e 3 O 4 core was successfully synthesized by the linker of Boc-L-cysteine.T ransmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX)a nd cyclic voltammograms (CV) were performedt oc haracterize the as-prepared Fe 3 O 4 @Au-Nps.T he results indicated that Au-Nps dispersed homogeneously around Fe 3 O 4 with the ratio of Au to Fe 3 O 4 nanoparticles as 5-10/1 andt he apparente lectrochemical area as 0.121 cm 2 .A fters elf-assembly of hemoglobin (Hb)o nF e 3 O 4 @Au-Npsb ye lectrostatic interaction,ahydrogen peroxide biosensor was developed. TheF e 3 O 4 @Au-Nps/Hbm odified GCE exhibited fast direct ele...

Autism is a disorder caused by nerve developmental disorders in childhood. Autism is a serious and widespread developmental disorder, with social disorders, speech development disorders, and poor language communication skills as typical symptoms, accompanied by stereotyped behaviors. With the improvement of our country's material living standards, the frequency of childhood autism is increasing year by year. Therefore, IoT smart toys specially designed for children with autism can meet their needs and help them to carry out rehabilitation education, so that they can obtain more benefits in the process of treatment and nurturing. Smart IoT toys are not only a design that pays attention to details, but also integrates care for children with autism into the design. This article aims to research based on the Internet of Things, starting with the design of toys for children with autism. This article applies the design ideas of smart IoT toys to APP product design, introduces emotional factors into APP products, and stimulates the profound emotional experience of ASD children. Designing products from the emotional perspective and details of smart Internet of things toys and the perspective of ASD children, analyze the emotional design factors of APP, and propose application programs for ASD children according to the design standards and methods of smart Internet of things toys. After studying the status quo of children with autism, it can be concluded that children with autism need special toys suitable for them. IoT smart toys can expand the design ideas of existing children’s educational toys, enrich the toy market, and provide children with more toys that meet their needs. According to the latest statistics from the US Centers for Disease Control and Prevention, from 2010 to 2014, the prevalence of children with autism in the United States rose from 0.0147 to 0.0169, and the prevalence of children with autism aged 0–14 exceeded 200,000. With the improvement of our country's material living standards, the frequency of childhood autism is increasing year by year.