A compound comprises a donor and an acceptor, wherein at least one donor (D) and at least one acceptor (A) may be arranged in an order of D-A; D-A-D; A-D-A; D-D-A-D-D; A-A-D-A-A; D-A-D-A-D; and A-D-A-D-A. The compound may be selected from the group consisting of: MTPE-TP, MTPE-TT, TPE-TP A-TT, PTZ-BT-TP A, NPB-TQ, TPE-TQ-A, MTPE-BTSe, DCDPP-2TP A, DCDPP-2TPA4M, DCDP-2TPA, DCDP-2TPA4M, TTS, ROpen-DTE-TPECM, and RClosed-DTE-TPECM. The compound may be used as a probe and may be functionalized with special targeted groups to image biological species. As non-limiting examples, the compound may be used in cellular cytoplasms or tissue imaging, blood vessel imaging, in vivo fluorescence imaging, brain vascular imaging, sentinel lymph node mapping, and tumor imaging, and the compound may be used as a photoacoustic agent.

The invention is directed to a staining composition and to the use of the staining composition in staining ocular tissue. In a first aspect, the invention provides a staining composition comprising a vital dye and a density increasing compound chosen from the group consisting of water soluble polymers and small inert molecules.

Provided are biosensors, compositions comprising biosensors, and methods of using biosensors in living cells and organisms. The biosensors are able to be selectively targeted to certain regions or structures within a cell. The biosensors may provide a signal when the biosensor is targeted and/or in response to a property of the cell or organism such as membrane potential, ion concentration or enzyme activity.

Provided herein are medical devices capable of self-reporting microbial growth adjacent the site of the implanted device.

The invention is directed to a staining composition and to the use of the staining composition in staining ocular tissue. In a first aspect, the invention provides a staining composition comprising a vital dye and a density increasing compound chosen from the group consisting of water soluble polymers and small inert molecules.

A method for functionalizing plant viral nanoparticles (VNPs) includes selecting a plant VNP. Additionally, a metal ion and a phenolic compound that form a metal-phenolic network (MPN), and at least one functional component that adheres to the MPN are also selected. A nanohybrid structure is synthesized from a solution of the selected metal, the selected phenolic compound and the selected functional component such that the synthesized nanohybrid structure has an MPN coating encapsulating the plant VNP with the functional component being embedded in the MPN coating.