Two birds with one stone:Amine-functionalized MSNs@Eu(OH)CO_(3) nanoprobe for efficient dissolution-enhanced afterglow bioassay

ABSTRACT The efficient detection of tumor markers is crucial to early cancer diagnosis and monitoring.Here,we propose a unique“two birds with one stone”dissolution-enhanced afterglow bioassay based on amino-functionalized mesoporous SiO2 nanoparticles(MSNs-NH2)encapsulated Eu(OH)CO_(3)nanoprobes.These nanoprobes(i)stably conjugate to the antibody and(ii)are highly soluble in the acidic enhancer solution,and provide a high Eu3+concentration.The released Eu3+ions further activate the photochemical afterglow system to determine the alpha-fetoprotein(AFP)levels in clinical serum samples.Without the use of a real-time excitation source,the interference of autofluorescence and scattering from blood can be avoided.The demonstrated limit of detection(LOD)for AFP was as low as 0.12 ng·mL^(−1).This covalently connected dissolution-enhanced luminescent bioassay(DELBA)and novel afterglow system shows tremendous potential for ultrasensitive and rapid clinical diagnosis.

Lanthanide-containing persistent luminescence materials with superbright red afterglow and excellent solution processability

Lanthanide-containing persistent luminescence materials are promising candidates for a wide range of applications by virtue of splendid superiorities in afterglow performance.However,it is a crucial challenge to achieve high-quality afterglow materials at the attractive nanoscale,with uniform size,controllable morphology,and satisfying brightness.Herein,a bottom-up approach was developed to construct the high-quality afterglow nanoparticles,incorporating luminescent lanthanide complex and organic molecular ingredients under mild conditions.These nanoparticles exhibited intrinsic lanthanide luminescence with superbright red afterglow(>10 cd m^(−2))in a homogeneous solution.The afterglow solution with excellent processability can serve as ideal building blocks for the on-demand fabrication of functional nanomaterials.Water-dispersible afterglow nanoparticles with state-of-the-art high brightness were uniformly constructed to perform whole-blood lateral flow assay of procalcitonin with a naked-eye detection limit of 0.5 ng mL^(−1),promoting the point-of-care testing development.

Luminescence interference-free lifetime nanothermometry pinpoints in vivo temperature

Luminescence nanothermometry makes non-invasive and real-time temperature readings possible in living animals.However,the spectral fluctuation in tissues and fluids,as well as the interaction between fluorophores and environment hinders accuracy of the thermometry.Here,we report a luminescence lifetime-based nanothermometry which specifically addresses this problem.A temporal based calibration(lifetime sensing)in the NIR range,an endogenous thermal response as well as a polymer encapsulation evading environmental factors,altogether help to pinpoint temperature in vivo.Thanks to the highly condensed NdYb ions in a well-protected tiny core-shell nanocrystal(overall 11 nm),a temperature sensitivity about 2.07%K^(-1)(with 5%Yb^(3+)doped nanoparticles)and an accuracy of 0.27 K(with 25%Yb^(3+)doped nanoparticles)in biological fluids are achieved.Hopefully,combining thermally activated energy transfer nanothermometer with anti-interference lifetime thermometry would provide a more accurate temperature measurement for biological and preclinical studies.

Engineering single-molecule fluorescence withasymmetric nano-antennas

As a powerful tool for studying molecular dynamics in bioscience,single-molecule fluorescence detection providesdynamical information buried in ensemble experiments.Fluorescence in the near-infrared(NIR)is particularly usefulbecause it offers higher signal-to-noise ratio and increased penetration depth in tissue compared with visiblefluorescence.The low quantum yield of most NIR fluorophores,however,makes the detection of single-moleculefluorescence difcult.Here,we use asymmetric plasmonic nano-antenna to enhance the fluorescence intensity ofAlEE1000,a typical NIR dye,by a factor up to 405.The asymmetric nano-antenna achieve such an enhancement mainlyby increasing the quantum yield(to~80%)rather than the local field,which degrades the molecules'photostability.Our coupled-mode-theory analysis reveals that the enhancements stem from resonance-matching between antennaand molecule and,more importantly,from optimizing the coupling between the near-and far-ield modes withdesigner asymmetric structures.Our work provides a universal scheme for engineering single-molecule fluorescence inthe near-infrared regime.

^(1)O_(2)-activatable Eu^(3+)-afterglow nanoprobe for highly sensitive detection of porphyria in whole blood

High-sensitivity detection of porphyrin in blood is very important for the early diagnosis and treatment of porphyria.Based on the advantages of longer luminescence lifetime and lower background interference,organic afterglow molecular porphyrin detection probes were developed,but these probes show poor water solubility and insufficient luminescence intensity.Herein,we present an afterglow nanoprobe(Eu-NP)for porphyria detection in whole blood.The luminescent substance(europium complex)and the organic vinyl co mpound reacted with singlet oxygen(^(1)O_(2))were selected for encapsulation in polystyrene spheres.Eu-NP can respond to^(1)O_(2)produced by porphyrins,and the detection signals can be obtained by the emission of the afterglow Eu^(3+)-emissive nanosensor.Eu-NP can achieve high-sensitivity detection of porphyrin,and the lowest detection limit reaches 0.29μmol/L.The porphyrin detection in whole blood samples is consistent with clinical diagnosis results.Compared with the organic afterglow molecule,the Eu-NPs constructed in this work show a higher signal-to-noise ratio and sensitivity of porphyria detection.

Synthesis of NaYF_4:Nd@NaLuF_4@SiO_2@PS colloids for fluorescence imaging in the second biological window

Nd doped nanoparticles is commonly used as bioimaging agents but presents poor stability. Here, a polymer coating is applied to NaYF4：Nd nanoparticles using a versatile step-by-step coating strategy. The as-synthesized NaYF_4：Nd@NaLuF_4@SiO_2@PS colloids show good stability in various polar solvent and are very stable in water at least for 6 months. These NaYF_4：Nd@NaLuF_4@SiO_2@PS colloids can exhibit strong down converting photoluminescence when excited by 808 nm lasers. Moreover, these NaYF_4：Nd@NaLuF_4@SiO_2@PS colloids accumulate in liver of mice when used as bio-imaging agents. which exhibit strong fluorescence luminescence in NIR Ⅱ window.