Disclosed are a fluorescent dye, a preparation method and an application thereof. The fluorescent dye has a structure of formula (I), where X and Y are independently selected from O, S, C(CH.sub.3).sub.2 and NR.sub.6; R.sub.2 and R.sub.3 are independently hydrogen or a functional group; R.sub.1, R.sub.4, R.sub.5 and R.sub.6 are independently selected from functional groups; and Z.sup. is a negative ion. The fluorescent dye has an ability to permeate the living cell membrane, so that it can be used in the fluorescence imaging of living cell microstructures, and can also be used in the STED super-resolution fluorescence imaging and laser scanning confocal microscopy of live cells.

Provided are a resin composition including a compound represented by Formula (1) and a resin, a film and a filter including the resin composition, a liquid crystal display device and a solid-state imaging element including the filter, and a compound suitable as a light absorbing component of the resin composition and the filter.

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In Formula (1), Dye represents a colorant structural part obtained by removing n1 hydrogen atoms from a squarylium compound having a specific structure. Q.sup.1 is a structural part in which energy levels of a highest occupied molecular orbital and a lowest unoccupied molecular orbital satisfy a specific condition. L.sup.1 represents a divalent linking group and n1 represents an integer of 1 to 4.

The present invention relates to an optical filter containing: an absorption layer containing a near-infrared absorbing dye (A) having a maximum absorption wavelength in dichloromethane being in a wavelength range of 850 to 1,100 nm and a transparent resin; and a reflection layer formed of a dielectric multilayer film, in which the near-infrared absorbing dye (A) satisfies the following Formulae (1) to (4).

ABS.sub.400(A)DCM/ABS.sub.max(A)DCM<0.10(1),

ABS.sub.550(A)DCM/ABS.sub.max(A)DCM<0.04(2),

ABS.sub.400(A)TR/ABS.sub.max(A)TR<0.15(3), and

ABS.sub.550(A)TR/ABS.sub.max(A)TR<0.10(4).

The present invention relates to an optical filter containing: an absorption layer containing a near-infrared absorbing dye satisfying the following (i-1) to (i-5), and a transparent resin; and a reflection layer, and satisfying the following (ii-1); (i-1) .sub.max(A) TR is in a wavelength range of 760 to 900 nm; (i-2) T.sub.435-480ave (A) TR and T.sub.480-590ave (A) TR are both 90% or more. (i-3) .sub.max(A) DCM is in a wavelength range of 760 to 900 nm. (i-4) T.sub.435-480ave (A) DCM is 95% or more and T.sub.480-590ave (A) DCM is 97% or more. (i-5) a difference between T.sub.435-480ave (A) DCM and T.sub.435-480ave (A) TR, and a difference between T.sub.480-590ave (A) DCM and T.sub.480-590ave (A) TR are 10.5% or less. (ii-1) an average transmittance of light in the wavelength range of 800 to 900 nm is 5% or less at an incident angle of 60 degrees.

The present invention relates to a compound of a pharmaceutically acceptable salt thereof of formula (I) wherein (A) is at least one motif specifically binding to cell membranes of neoplastic cells; (B) at least one chelator moiety of radiometals; (C) a dye moiety; x.sub.1 is a spacer or a chemical single bond covalently connecting (A) to the rest of the molecule; x.sub.2 is a spacer or a chemical single bond covalently connecting (C) to the rest of the molecule. The invention further relates to compositions comprising said compounds as well as a method for detecting neoplastic cells in a sample in vitro with the aid of the compounds or composition.

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The present invention is directed, in certain embodiments, to polymerizable near-IR dyes and polymers comprising said dyes as monomeric residues. In other embodiments, the present invention also relates to methods for the preparation of polymerizable near-IR dyes, and to the use of polymerizable near-IR dyes in the preparation of fluorescent polymers.

A group of fluorescent polymeric coating films visible in near-infrared light for coating a medical device, and a method for preparing such NIR visible polymeric coating films.

The present disclosure relates to chemical dyes useful for staining and imaging of cells. In particular, the disclosure relates to compound of Formula I, method of preparation thereof, and it's use as a fluorescent probe for staining and/or imaging mitochondria in cells, tissues or animals, resulting in a range of applications including, but not limiting, to sensing local ordering or viscosity of mitochondria, tracking mitochondrial mobility, comparing & evaluating mitochondrial function, local ordering, microviscosity and dynamics. Said dyes have additional advantages including, but not limiting, to low toxicity, longer shelf-life, generate little or no reactive species upon long term light irradiation and do not perturb the functionality of the mitochondria in cells compared to prior art dyes. ##STR00001##

The design, synthesis, and functionalization of a conjugate including a tumor-targeting near-infrared (NIR) dye and a therapeutic agent and/or a diagnostic agent, whereby the NIR dye can function to target the therapeutic agent and/or diagnostic agent to tumor cells.

Problem to Be Solved: to provide a chromophore having a far superior nonlinear optical activity to conventional chromophores and to provide a nonlinear optical element comprising said chromophore. Solution: a chromophore comprising a donor structure D, a -conjugated bridge structure B, and an acceptor structure A, the donor structure D comprising an aryl group substituted with a substituted oxy group; and a nonlinear optical element comprising said chromophore.