荧光分子探针助力疾病标志物检测

荧光分子探针已成为当代化学生物学和生物医药领域不可或缺的研究工具,被成功应用于活细胞内重要生物物种的动态可视化和人类重大疾病的早期诊治研究.本文总结了包括阴、阳离子,活性氧、氮、碳、硫物种和酶在内的重要生物标志物在疾病发生发展中的生物学功能,以及细胞和活体层次靶向可视化这些标志物的荧光分子探针前沿进展,归纳了现有探针体系所面临的问题和挑战,并展望了该领域的发展方向.

2D-ultrathin MXene/DOXjade platform for iron chelation chemo-photothermal therapy

An increased demand for iron is a hallmark of cancer cells and is thought necessary to promote high cell proliferation,tumor progression and metastasis.This makes iron metabolism an attractive therapeutic target.Unfortunately,current iron-based therapeutic strategies often lack effectiveness and can elicit off-target toxicities.We report here a dual-therapeutic prodrug,DOXjade,that allows for iron chelation chemo-photothermal cancer therapy.This prodrug takes advantage of the clinically approved iron chelator deferasirox(ExJade®)and the topoisomerase 2 inhibitor,doxorubicin(DOX).Loading DOXjade onto ultrathin 2D Ti_(3)C_(2) MXene nanosheets produces a construct,Ti_(3)C_(2)-PVP@DOXjade,that allows the iron chelation and chemotherapeutic functions of DOXjade to be photo-activated at the tumor sites,while potentiating a robust photothermal effect with photothermal conversion efficiencies of up to 40%.Antitumor mechanistic investigations reveal that upon activation,Ti_(3)C_(2)-PVP@DOXjade serves to promote apoptotic cell death and downregulate the iron depletion-induced iron transferrin receptor(TfR).A tumor pH-responsive iron chelation/photothermal/chemotherapy antitumor effect was achieved both in vitro and in vivo.The results of this study highlight what may constitute a promising iron chelation-based phototherapeutic approach to cancer therapy.

Dual enzyme activated fluorescein based fluorescent probe

A simple dual analyte fluorescein-based probe(PF3-Glc)was synthesised containingβ-glucosidase(β-glc)and hydrogen peroxide(H2O2)trigger units.The presence ofβ-glc,resulted in fragmentation of the parent molecule releasing glucose and the slightly fluorescent mono-boronate fluorescein(PF3).Subsequently,in the presence of glucose oxidase(GOx),the released glucose was catalytically converted to D-glucono-δ-lactone,which produced H2O2 as a by-product.The GOx-produced H2O2,resulted in classic H2O2-mediated boronate oxidation and the release of the highly emissive fluorophore,fluorescein.This unique cascade reaction lead to an 80-fold increase in fluorescence intensity.

A boronic acid-based fluorescent hydrogel for monosaccharide detection

A boronic acid-based anthracene fluorescent probe was functionalised with an acrylamide unit to incorporate into a hydrogel system for monosaccharide detection.In solution,the fluorescent probe displayed a strong fluorescence turn-on response upon exposure to fructose,and an expected trend in apparent binding constants,as judged by a fluorescence response where D-fructose>D-galactose>D-mannose>D-glucose.The hydrogel incorporating the boronic acid monomer demonstrated the ability to detect monosaccharides by fluorescence with the same overall trend as the monomer in solution with the addition of D-fructose resulting in a 10-fold enhancement(≤0.25 mol/L).

A simple,azulene-based colorimetric probe for the detection of nitrite in water

We describe the synthesis and evaluation of an azulene-based chemodosimeter for nitrite.The probe was found to undergo two distinct color changes upon introduction of aqueous nitrite ion.A near-instant formation of a grey color provides a qualitative indication of the presence of nitrite,followed by the formation of a deep-yellow/orange color,the endpoint from which quantitative data can be derived.The azulene probe exhibits 1:1 stoichiometry of reaction with nitrite in water,and is selective for nitrite over other anions.The azulene probe was applied to determine nitrite content in cured meat,and compared with the British Standard testing procedure(Griess test).The value obtained from the azulene-based probe agreed closely with the standard test.Our procedure only requires the preparation of one standard solution,instead of the three required for the standard Griess test.

Special issue on “Fluorescent probes”

Fluorescent probes are intelligently designed molecules that transform the act of binding/reacting with a target analyte into an optical signal[1,2].Their high sensitivity and specificity coupled with high spatial and temporal resolution offers a non-invasive approach to observe a specific analyte within complex biological environments in real time with high precision[3].These"molecular tools"have the capability to interrogate the role of specific biomarkers that are associated with a particular disease state or can be used to improve our understanding of the role or certain species in a biological pathway[4,5].