The spin–orbit charge-transfer-induced intersystem crossing (SOCT-ISC) in Bodipy-phenoxazine (BDP-PXZ) compact electron-donor/-acceptor dyads was studied. PXZ is the electron donor, and BDP is the electron acceptor. The molecular geometry is varied by applying different steric hindrance on the rotation about the linker between the two subunits. Charge-transfer (CT) absorption bands were observed for the dyads with more coplanar geometry (electronic coupling matrix elements is up to 2580 cm–1). Ultrafast charge separation (0.4 ps) and slow charge recombination (3.8 ns, i.e., SOCT-ISC process) were observed. Efficient ISC (ΦT = 54%) and long triplet-state lifetime (τT = 539 μs) were observed for the dyads. Notably, the triplet-state lifetime is 2-fold of that accessed with heavy-atom effect, indicating the advantage of using a heavy-atom-free photosensitizer. The low-lying CT state in the dyads in polar solvents was confirmed with intermolecular triplet photosensitizing method. Time-resolved electron paramagnetic resonance spectroscopy show that the electron spin polarization of the triplet state formed by the SOCT-ISC is the same as that of spin–orbit-ISC (SO-ISC). 3CT and localized excited triplet states (3LE) were simultaneously observed for one of the dyads, which is rare. Normally, the CT state was observed as spin-correlated radical pair. The dyads were used as triplet photosensitizers for triplet–triplet annihilation upconversion, the quantum yield is up to 12.3%. A large anti-Stokes shift (5905 cm–1) was achieved by excitation into the CT absorption band, not the conventional LE absorption band.

Glioblastoma (GBM) is one of the most fatal tumors in the brain, and its early diagnosis remains technically challenging due to the complex repertoires of oncogenic alterations and blood-brain barrier (BBB). GBM-derived specific exosomes can cross the BBB and circulate in body fluids, so they can be noninvasive biomarkers for the early diagnosis of GBM. Herein, we propose a sensitive and label-free electrochemical biosensor designed by using Zr-based metal–organic frameworks (Zr-MOFs) for the detection of GBM-derived exosomes with practical application. In the design, a peptide ligand can specifically bind with human epidermal growth factor receptor (EGFR) and EGFR variant (v) III mutation (EGFRvIII), which are overexpressed on the GBM-derived exosomes. Meanwhile, Zr-MOFs encapsulated with methylene blue can absorb on the surface of the exosomes due to the interaction between Zr4+ and the intrinsic phosphate groups outside of exosomes. Consequently, the concentration of exosomes can be directly quantified by monitoring the electroactive molecules inside MOFs, ranging from 9.5 × 103 to 1.9 × 107 particles/μL with the detection of limit of 7.83 × 103 particles/μL. Furthermore, this proposed biosensor can distinguish GBM patients from healthy groups, demonstrating the great prospect for early clinical diagnosis.

A Bodipy derivative with twisted π-conjugation system is demonstrated that shows efficient intersystem crossing (ISC) (singlet oxygen quantum yield ΦΔ = 55%) and a long-lived triplet state (τT = 197.5 μs) with high energy (E T1 = 1.44–1.53 eV). This is superior to the conventional heavy-atom-enhanced ISC in a reference Bodipy compound, which results in much shorter triplet state lifetime (3.3 μs) and lower triplet-state energy (1.2 eV).

Recently varieties of Bodipy derivatives showing intersystem crossing (ISC) have been reported as triplet photosensitizers, and the application of these compounds in photocatalysis, photodynamic therapy (PDT), and photon upconversion are promising. In this review we summarized the recent development in the area of Bodipy-derived triplet photosensitizers and discussed the molecular structural factors that enhance the ISC ability. The compounds are introduced based on their ISC mechanisms, which include the heavy atom effect, exciton coupling, charge recombination (CR)-induced ISC, using a spin converter and radical enhanced ISC. Some transition metal complexes containing Bodipy chromophores are also discussed. The applications of these new triplet photosensitizers in photodynamic therapy, photocatalysis, and photon upconversion are briefly commented on. We believe the study of new triplet photosensitizers and the application of these novel materials in the abovementioned areas will be blooming.

The photophysical properties of a heavy atom-free Bodipy derivative with twisted π-conjugation framework were studied. Efficient intersystem crossing (ISC. Quantum yield: 56%) and exceptionally long-lived triplet state wereobserved (4.5 ms....

An integrated microfluidic system was developed for extracellular vesicle (EV) enrichment and quantification by using anti-CD63-coated magnetic beads and an on-chip enzyme-linked immunosorbent assay in human whole blood.

Orthogonal phenoxazine‐styryl BODIPY compact electron donor/acceptor dyads were prepared as heavy atom‐free triplet photosensitizers (PSs) with strong red light absorption ( ϵ =1.33×10 5 M −1 cm −1 at 630 nm), whereas the previously reported triplet photosensitizers based on the spin‐orbit charge transfer intersystem crossing (SOCT‐ISC) mechanism show absorption in a shorter wavelength range (<500 nm). More importantly, a long‐lived triplet state (τ T =333 μs) was observed for the new dyads. In comparison, the triplet state lifetime of the same chromophore accessed with the conventional heavy atom effect (HAE) is much shorter (τ T =1.8 μs). Long triplet state lifetime is beneficial to enhance electron or energy transfer, the primary photophysical processes in the application of triplet PSs. Our approach is based on SOCT‐ISC, without invoking of the HAE, which may shorten the triplet state lifetime. We used bisstyrylBodipy both as the electron acceptor and the visible light‐harvesting chromophore, which shows red‐light absorption. Femtosecond transient absorption spectra indicated the charge separation (109 ps) and SOCT‐ISC (charge recombination, CR; 2.3 ns) for BDP‐1 . ISC efficiency of BDP‐1 was determined as Φ T =25 % (in toluene). The dyad BDP‐3 was used as triplet PS for triplet‐triplet annihilation upconversion (upconversion quantum yield Φ UC =1.5 %; anti‐Stokes shift is 5900 cm −1 ).

The three-dimensional conformations adopted by a free ligand in solution impact bioactivity and physicochemical properties. Solution 1D NMR spectra inherently contain information on ligand conformational flexibility and three-dimensional shape, as well as the propensity of the free ligand to fully preorganize into the bioactive conformation. Herein we discuss some key learnings, distilled from our experience developing potent and selective synthetic macrocyclic inhibitors, including Mcl-1 clinical candidate AZD5991. Case studies have been selected from recent oncology research projects, demonstrating how 1D NMR conformational signatures can complement X-ray protein−ligand structural information to guide medicinal chemistry optimization. Learning to extract free ligand conformational information from routinely available 1D NMR signatures has proven to be fast enough to guide medicinal chemistry decisions within design cycles for compound optimization.