A NEW SOLVENT POLYMERIC MEMBRANE pH SENSOR WITH WIDE LINEAR pH RANGE

A new solvent polymeric membrane (SPM)pH2sensor based on 4,4'-bis (N, N-didecylamino)methyl)azobenzene as neutral carricr has been reported. It has excellent pH response characteristics with the linear response range (1.7—13.2)much wider than that of similar SPM pH sensors reported so far. The sensor has a theoretical Nernstian response of 57.4+0.2V/pH(at 20℃)without super—Nernstian response phenomenon.

Research advancement of DNA-based intelligent hydrogels:Manufacture, characteristics, application of disease diagnosis and treatment

DNA-based hydrogels are exceptional materials for biological applications because of their numerous advantages such as biodegradability,biocompatibility,hydrophilicity,super absorbency,porosity,and swelling.Among these advantages,the ability of DNA-based hydrogels to respond to specific physical and chemical triggers and undergo reversible phase transitions has garnered significant attention in the fields of disease diagnosis(biosensors)and treatment(drug delivery).This article focuses on the recent advancements in the research of DNA-based hydrogels and discusses the different types of these hydrogels,the synthetic methods,their unique properties,and their applications in biosensors and drug delivery.The types of DNA hydrogels are categorized based on their building blocks,and the process of synthesis as well as the unique characteristics of DNA-based hydrogels are described.Then,DNA-based responsive hydrogels utilized as intelligent materials for the development of biosensors are reviewed.Furthermore,this article also presents the current status of DNA-based responsive hydrogels in drug delivery for cancer treatment,wound healing,and other therapeutic applications.Ultimately,this paper discusses the current challenges in expanding the practical application of DNA-based hydrogels.

Advanced Pt hollow nanospheres/rubrene nanoleaves coupled with M-shaped DNA walker for ultrasensitive electrochemiluminescence bioassay

Herein,an intense electrochemiluminescence(ECL)was achieved based on Pt hollow nanospheres/rubrene nanoleaves(Pt HNSs/Rub NLs)without the addition of any coreactant,which was employed for ultrasensitive detection of carcinoembryonic antigen(CEA)coupled with an M-shaped DNA walker(M-DNA walker)as signal switch.Specifically,in comparison with platinum nanoparticles(Pt NPs),Pt HNSs revealed excellent catalytic performance and pore confinement-enhanced ECL,which could significantly amplify ECL intensity of Rub NLs/dissolved O_(2)(DO)binary system.Then,the tracks and M-DNA walker were confined on the Pt HNSs simultaneously to promote the reaction efficiency,whose M-structure boosted the interaction sites between walking strands and tracks and reduced the rigidity of their recognition.Once the CEA approached the sensing interface,the M-DNA walker was activated based on highly specific aptamer recognition to recover ECL intensity with the assistance of exonucleaseⅢ(ExoⅢ).As proof of concept,the“on-off-on”switch aptasensor was constructed for CEA detection with a low detection limit of 0.20 fg/m L.The principle of the constructed ECL aptasensor also enables a universal platform for sensitive detection of other tumor markers.

ECL金属-有机框架(MOF)生物传感平台用于肿瘤细胞分泌H_(2)O_(2)的测定

本工作借助金属-有机框架(MOF)结构,通过配位作用实现对电化学发光(ECL)分子的空间有序组装,获得了高性能ECL新材料,发展了孔道限域效应和微纳空间ECL分子有序组装的协同增强ECL新策略.具体而言,以非共平面ECL分子1,1,2,2-四(4-羧基苯)乙烯(H4TCPE)为配体采用一步水热法合成了具有优异ECL性能的新型MOF材料(Zr-TCPE).Zr-TCPE通过将发光配体H4TCPE固定在MOF多孔材料上,一方面其多孔结构可以促进限域空间内物质和电子的传递,加快电化学反应的效率;同时,MOF结构的配位键合作用限制了发光基团的自由转动与振动以及分子间的紧密堆积,从而有效减少了非辐射弛豫和内滤效应.和H4TCPE的微纳晶体相比,Zr-TCPE的ECL强度提高了3.46倍,ECL效率提高了17.44倍.采用Zr-TCPE构建了ECL生物传感平台,成功实现了在药物刺激下肿瘤细胞释放过氧化氢(H_(2)O_(2))的原位监测,对临床检测肿瘤细胞具有指导意义.

CDs assembled metal-organic framework:Exogenous coreactant-free biosensing platform with pore confinement-enhanced electrochemiluminescence

Despite the various synthesis approachs to obtain luminous carbon dots(CDs),it is still quite challenging to construct the efficient electrochemiluminescence(ECL)owing to their low ECL reactivity and easy agglomeration.Herein,an efficient and concise ECL system was skillfully constructed by taking advantage of the nitrogen and sulfur co-doped CDs(N,S-CDs)with surfaces rich in hydrazide groups as luminophors to emit intense ECL,and metal-organic framework(MOF)as the matrix to confine CDs in its nanospace.Surprisingly,the proposed CDs assembled MOF(CDs/ZIF-8)enhanced anodic ECL signal up to 250%of pure CDs under the exogenous coreactant-free condition.As a proof of concept,the highly sensitive detection of uric acid(UA)was realized by the constructed ECL platform with a low detection limit of 3.52 nmol/L ranging from 10 nmol/L to 50μmol/L.This work expanded ideas for the application of pore confinement effect,and provided references for the detection of disease biomarkers of gout and hyperuricemia.

Target Recycling Transcription of Lighting-Up RNA Aptamers for Highly Sensitive and Label-Free Detection of ATP

We describe here a target recycling transcription of lighting-up aptamer strategy for detecting ATP in human serums in a label-free means with high sensitivity.ATP molecules specifically recognize the binding aptamer and result in the structure switching of the DNA assembly probes to imitate the target ATP molecule recycling cycles through the toehold-mediated strand displacement reaction,which causes the formation of many dsDNAs containing the RNA promoter sequences for subsequent transcription generation of large amounts of lighting-up aptamers.The organic dye,malachite green,then associates with these lighting-up aptamers to produce significantly enhanced fluorescence signals,which can sensitively detect ATP within a dynamic range from 10 to 500 nM in a label-free way.The sensing approach shows a detection limit of 7.3 nM and also has an excellent selectivity for ATP analogue molecules.In addition,this method can detect ATP molecules in diluted human serum samples sensitively,which proves the promising potential to diagnose ATP-related diseases.

Unmodified and positively charged gold nanoparticles for sensitive colorimetric detection of folate receptor via terminal protection of small molecule-linked ss DNA

The detection of protein/small molecule interactions plays important roles in drug discovery and protein/metabolite interactions in biology. In this work, by coupling the terminal protection of small molecule-linked ss DNA strategy with the unmodified and positively charged gold nanoparticle((+)Au NP) nanoprobes, we have developed a sensitive and simple colorimetric sensor for the detection of folate receptor, a highly expressed protein in many kinds of malignant tumors. The target folate receptor binds the folate moieties of the folate-linked ss DNA through high affinity interactions and protects the protein-bound ss DNA from digestion by exonuclease I. The protected ss DNA thus adsorbs the((+)Au NP) through electrostatic interactions, leading to a red-to-blue color change of the sensing solution for sensitive colorimetric detection of folate receptor at the sub-nanomolar level. Besides, this colorimetric sensor shows high selectivity toward folate receptor against other control proteins. The developed sensor avoids the modification/conjugation of the Au NP nanoprobes and the involvement of any expensive instruments for signal transduction in protein detection. Featured with these obvious advantages, the colorimetric sensor strategy demonstrated herein can be easily expanded for sensitive and convenient detection of various protein/small molecule interactions.