Ruinian Hua

Molecular stacking plays a critical role in ultralong organic phosphorescence (UOP) generation under ambient conditions. To better understand how the crystal packing affects UOP and achieve efficient UOP, herein, a combined experimental and theoretical study of the synthesized S,S-dioxide phenothiazine derivatives was performed, in which methyl groups with different numbers and substitution sites were used to modulate the solid-state packing. All compounds showed similar photophysical characteristics in solution, but distinct UOP behaviors in the crystalline state. m-DMOPP crystals possessing two methyl moieties and densely ordered stacking can achieve a longer lifetime of 375 ms and higher phosphorescent efficiency. The potential applications in anticounterfeiting and 3D patterning based on m-DMOPP were realized in virtue of its excellent UOP character. Importantly, the changes in displacement between adjacent molecules along the Y-axis had a more significant impact on the intersystem crossing process than that along the Z-axis in such H-aggregation phenothiazine-based materials. Our investigation would provide a profound understanding of the relationship between molecular stacking and UOP properties and a feasible molecule strategy to design ideal UOP materials.

Diabetic nephropathy (DN) is the most common microvascular complication associated with incurable diabetes. The gold standard diagnostic method for DN is based on the detection of proteinuria but it overlooks cases of non-proteinuria (NP-DN). To address this limitation, urinary sialic acid (SA) has been confirmed as an effective biomarker for various DNs. Herein, we constructed an ultrasensitive non-proteinuria assay platform to accurately diagnose DN within 20 min. This platform utilized the ninhydrin reaction between acidic ninhydrin and urinary sialic acid (SA) as an effective biomarker for various DNs. A compound with a maximum absorption peak at 470 nm was produced in this reaction and contributed to the fluorescence decrease of the blue-emission core–shell upconverting nanoparticles through the inner filter effect (IFE). By integrating the inner filter effect (IFE) with a mimetic immunoassay, the imperceptible color was converted into highly sensitive fluorescence signals. This protocol shows a stable and high sensitivity with a detection limit of 20 nmol L⁻¹ and provides 100% positive prediction for urine samples, demonstrating its potential for clinical diagnosis and long-term monitoring of DN.

Quadruply doped (Nd³⁺, Tm³⁺, Er³⁺ and Yb³⁺) core–shell structure NaYF₄ UCNPs achieve multi-color luminescence based on a single material under 980 nm excitation. Their applicability to anticounterfeiting and information storage has been verified.

In this Reply, we truthfully respond to the comments on our recent paper entitled “A universal approach for calculating the Judd–Ofelt parameters of RE³⁺ in powdered phosphors and its application for the β-NaYF₄:Er³⁺/Yb³⁺ phosphor derived from auto-combustion-assisted fluoridation” published in Phys. Chem. Chem. Phys. [Y. Zhang, B. Chen, S. Xu, X. Li, J. Zhang, J. Sun, X. Zhang, H. Xia, R. Hua, A universal approach for calculating the Judd–Ofelt parameters of RE3+ in powdered phosphors and its application for the beta-NaYF4:Er3+/Yb3+ phosphor derived from auto-combustion-assisted fluoridation, Phys. Chem. Chem. Phys., 20, 2018, 15876–15883]. In the Comment, the authors oppugned partial calculation results we reported in our original paper, thus we redid the calculations and compared the presently obtained results with the original ones and the author provided ones. The recalculations and comparisons confirmed that our calculations are reproducible and the results are correct. In the Comment, the authors also made some comments on the Judd–Ofelt calculation approaches for powdered samples reported by other researchers. Following the authors’ train of thought we added some supplements to the comments to understand the application strategy of Judd–Ofelt theory. Furthermore, we extended some points of view regarding the fluorescence lifetime measurements the authors presented in the Comment.