Lei Zhang

The design and characterization of thermally activated delayed fluorescence (TADF) materials for optoelectronic applications represents an active area of recent research in organoelectronics. Noble metal-free TADF molecules offer unique optical and electronic properties arising from the efficient transition and interconversion between the lowest singlet (S1 ) and triplet (T1 ) excited states. Their ability to harvest triplet excitons for fluorescence through facilitated reverse intersystem crossing (T1 →S1 ) could directly impact their properties and performances, which is attractive for a wide variety of low-cost optoelectronic devices. TADF-based organic light-emitting diodes, oxygen, and temperature sensors show significantly upgraded device performances that are comparable to the ones of traditional rare-metal complexes. Here we present an overview of the quick development in TADF mechanisms, materials, and applications. Fundamental principles on design strategies of TADF materials and the common relationship between the molecular structures and optoelectronic properties for diverse research topics and a survey of recent progress in the development of TADF materials, with a particular emphasis on their different types of metal-organic complexes, D-A molecules, and fullerenes, are highlighted. The success in the breakthrough of the theoretical and technical challenges that arise in developing high-performance TADF materials may pave the way to shape the future of organoelectronics.

PURPOSE: Multiplexing assay of biomarkers at the point-of-care is an elusive goal for molecular diagnostics. EXPERIMENTAL DESIGN: Here, we report an electrochemical (EC) sensor for oral cancer detection based on the simultaneous detection of two salivary biomarkers: interleukin (IL)-8 mRNA and IL-8 protein. RESULTS: Under the multiplexing mode, the limit of detection of salivary IL-8 mRNA reaches to 3.9 fM and 7.4 pg/mL for IL-8 protein in saliva. Multiplex assay of these 2 biomarkers directly from 28 cancer and 28 matched control saliva samples shows significant difference between the two groups. From the receiver operating characteristic analysis, the EC sensor yields around 90% sensitivity and specificity for both IL-8 mRNA and IL-8 protein, which are very close to the data measured by traditional assays (ELISA and PCR) with the same group of saliva. Combined IL-8 mRNA and protein show better AUC compared with single biomarker. CONCLUSIONS: We show, for the first time, concurrently multiplexing detection of salivary mRNA and protein biomarkers using point-of-care EC sensor.

We demonstrate that phosphazene bases, such as 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) and N‘-tert-butyl-N,N,N‘,N‘,N‘ ‘,N‘ ‘-hexamethylphosphorimidic triamide (P1-t-Bu), are active organocatalysts for the living ring-opening polymerization (ROP) of cyclic esters. Polyesters prepared through this organocatalytic route possess predictable molecular weights, narrow polydispersities, and high end-group fidelity. Mechanistic studies suggest that the intermolecular hydrogen bonding of the alcohol initiator to phosphazene bases activates the alcohol for ROP of cyclic esters.

Compared with imaging in the visible (400–650 nm) and near‐infrared window I (NIR‐I, 650–900 nm) regions, imaging in near‐infrared window II (NIR‐II, 1000–1700 nm) is a highly promising in vivo imaging modality with improved resolution and deeper tissue penetration. Here, a small molecule NIR‐II dye,5,5′‐(1H,5H‐benzo[1,2‐c:4,5‐c′] bis[1,2,5]thiadiazole)‐4,8‐diyl)bis( N , N ‐bis(4‐(3‐((tert‐butyldimethylsilyl)oxy)propyl)phenyl) thiophen‐2‐amine), is successfully encapsulated into phospholipid vesicles to prepare a probe CQS1000. The novel NIR‐II probe is studied for in vivo multifunctional biological imaging. The results of this study indicate that the NIR‐II vesicle CQS1000 can noninvasively and dynamically visualize and monitor many physiological and pathological conditions of circulatory systems, including lymphatic drainage and routing, angiogenesis of tumor, and vascular deformity such as arterial thrombus formation and ischemia with high spatial and temporal resolution. More importantly, by virtue of the favorable half‐life of blood circulation of CQS1000, NIR‐II imaging is capable of aiding precise resection of tumor such as osteosarcoma and accelerating the process of lymph node dissection to complete sentinel lymph node biopsy for better decision making during the tumor surgery. Overall, CQS1000 is a highly promising NIR‐II probe for multifunctional biomedical imaging in physiological and pathological conditions, surpassing traditional NIR‐I imaging modality and pathologic assessments for clinical diagnosis and treatment.

In order to promote imaging-guided chemotherapy for preclinical and clinical applications, endogenous nanosystems with both contrast and drug-delivery properties are highly desired. Here, the simple use of melanin is first reported, and this biopolymer with good biocompatibility and biodegradability, binding ability to drugs and ions, and intrinsic photoacoustic properties, can serve as an efficient endogenous nanosystem for imaging-guided tumor chemotherapy in living mice. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.