Fluorophore and fluorescent sensor compound containing same

Abstract

The invention provides fluorophores of formulae (I) and (II) and also fluorescent sensor compounds comprising fluorophore moieties based on such fluorophores in combination with a receptor moiety: There is further provided a method of sensing the presence of a target analyte using the fluorescent sensor compound, as well as the use of the fluorescent sensor compounds to sense a target analyte.

1 . A fluorescent sensor compound comprising a fluorophore moiety and a receptor moiety, wherein the receptor moiety is capable of selectively interacting with an analyte and wherein the fluorescence of the fluorophore moiety is perturbed upon interaction of the receptor moiety with said analyte, characterised in that the fluorophore moiety is of formula (IIa): 
       
         
           
           
               
               
           
         
         wherein:
 two of a, b and c are zero and the other one of a, b and c is one; 
 R is selected from C 6-14  aryl, 5- to 10-membered heteroaryl, C 3-7  carbocyclyl, 5- to 10-membered heterocyclyl, C 1-10  alkyl, C 1-10  alkoxy, —C 1-10  alkyl-SR 7  (where R 7  represents hydrogen or C 1-10  alkyl), C 2-10  alkenyl, C 2-10  alkenyloxy, C 1-10  haloalkyl, C 2-10  haloalkenyl, C 1-10  haloalkoxy, C 2-10  haloalkenyloxy, hydroxyl, C 1-10  hydroxyalkyl and —NR 8 R 9  where R 8  and R 9 , are the same or different and represent hydrogen or C 1-4  alkyl, wherein the alkyl, carbocylyl, heterocyclyl, aryl and heteroaryl groups or moieties of R may optionally bear one or more polymerisable groups and/or one or more ionic water-solubilising groups or the aryl and heteroaryl groups and moieties of R may themselves represent a cyclic ionic water-solubilising substituent; and 
 R 1′  represents the point of attachment of the fluorophore moiety to the rest of the fluorescent sensor compound; 
 
         wherein the phenyl groups in the anthracenyl moiety of formula (IIa) are optionally further substituted by one or more optional substituents, and wherein the phenyl groups in the anthracenyl moiety of formula (IIa) may optionally bear one or more ionic water-solubilising groups and/or one or more polymerisable groups. 
       
     
     
         2 - 5 . (canceled) 
     
     
         6 . A fluorescent sensor compound as claimed in  claim 1  wherein R is selected from C 6-10  aryl, 5- to 6-membered heteroaryl, C 3-7  carbocyclyl, 5- to 6-membered heterocyclyl, C 1-6  alkyl, C 1-6  alkoxy, —C 1-10  alkyl-SR 7  (where R 7  represents hydrogen or C 1-6  alkyl), C 1-6  haloalkyl, C 1-6  haloalkoxy, C 1-10  hydroxyalkyl and —NR 8 R 9  where R 8  and R 9  are the same or different and represent hydrogen or C 1-2  alkyl. 
     
     
         7 . A fluorescent sensor compound as claimed in  claim 6  wherein R represents a C 1-6  alkyl group which is unsubstituted or substituted with 1, 2 or 3 unsubstituted substituents which are the same or different and are selected from halogen atoms and C 1-4  alkyl, C 2-4  alkenyl, C 1-4  alkoxy, C 2-4  alkenyloxy, C 1-4  haloalkyl, C 2-4  haloalkenyl, C 1-4  haloalkoxy, C 2-4  haloalkenyloxy, hydroxyl, cyano, nitro, C 1-4  hydroxyalkyl, —OSiR′R″R′″, —SR 7  and —NR′R″ groups where R′, R ″  and R ′″  are the same or different and represent hydrogen or unsubstituted C 1-4  alkyl. 
     
     
         8 . A fluorescent sensor compound as claimed in  claim 6  wherein b is one and a and c are zero. 
     
     
         9 - 10 . (canceled) 
     
     
         11 . A fluorescent sensor compound as claimed in  claim 1  wherein the receptor moiety of the fluorescent sensor compound comprises one or more binding groups which are capable of binding to the target analyte, said binding group or groups being boronic acid groups. 
     
     
         12 . A fluorescent sensor compound as claimed in  claim 11  wherein the binding groups of the receptor moiety are separated by an aliphatic spacer moiety, and wherein said spacer moiety is selected from a C 1-10  alkyl or C 3-10  carbocyclyl group. 
     
     
         13 . A fluorescent sensor compound as claimed in  claim 11  wherein the receptor moiety comprises a group of formula (A): 
       
         
           
           
               
               
           
         
         wherein X 1  and X 2  are the same or different and represent a group -(Alk 1 ) n -Y1 or -(Alk 1 ) n -Y2 respectively where Alk 1  is a C 1-2  alkyl group, n is zero or 1, and Y 1  and Y2 are the same or different and represent a boronic acid binding group. 
       
     
     
         14 . A fluorescent sensor compound as claimed in  claim 13  wherein a spacer group is present between the fluorophore moiety and the receptor moiety of formula (A), and wherein this spacer group is a C 1-6  alkyl group, more preferably a C 1-3  alkyl group, more preferably a C 2-3  alkyl group, most preferably an ethylene group. 
     
     
         15 . A fluorescent sensor compound as claimed in  claim 1  comprising a polymerisable group selected from (meth)acrylate, (meth)acrylamide vinylbenzyl and N-vinylamide groups. 
     
     
         16 . (canceled) 
     
     
         17 . A fluorescent sensor compound as claimed in  claim 1  wherein the fluorophore moiety is 10-({6-[4-(2-Acryloyloxyethyl)benzyl-(2-{boronic acid}benzyl)-amino]hexyl-(2-{boronic acid}benzyl)amino}methyl)-N-[2-(methoxy)ethyl]-anthracene-1,9-dicarboxylic imide 
     
     
         18 . (canceled) 
     
     
         19 . A method of detecting the presence of an analyte in a test substance, which method comprises:
 (i) exposing a fluorescent sensor compound as claimed in  claim 1  to a test substance and measuring the fluorescence of the compound;   (ii) comparing the fluorescence measurement obtained in step (i) against a previously-determined fluorescence measurement of the fluorescent sensor compound in the absence of the target analyte; and   (iii) determining that the target analyte is present if the fluorescence measurement obtained in step (ii) is different from the previously-determined fluorescence measurement.   
     
     
         20 - 24 . (canceled) 
     
     
         25 . A fluorophore of formula (II) or a salt thereof: 
       
         
           
           
               
               
           
         
         wherein:
 two of a, b and c are zero and the other one of a, b and c is one; 
 R is selected from C 6-14  aryl, 5- to 10-membered heteroaryl, C 3-7  carbocyclyl, 5- to 10-membered heterocyclyl, C 1-10  alkyl, C 1-10  alkoxy, —C 1-10  alkyl-SR 7  (where R 7  represents hydrogen or C 1-10  alkyl), C 2-10  alkenyl, C 2-10  alkenyloxy, C 1-10  haloalkyl, C 2-10  haloalkenyl, C 1-10  haloalkoxy, C 2-10  haloalkenyloxy, hydroxyl, C 1-10  hydroxyalkyl and —NR 8 R 9  where R 8  and R 9  are the same or different and represent hydrogen or C 1-4  alkyl, wherein the alkyl, carbocylyl, heterocyclyl, aryl and heteroaryl groups or moieties of R may optionally bear one or more polymerisable groups and/or one or more ionic water-solubilising groups or the aryl and heteroaryl groups and moieties of R may themselves represent a cyclic ionic water-solubilising substituent; and 
 R 1′  represents the point of attachment of the fluorophore moiety to the rest of the fluorescent sensor compound; 
 
         and wherein the phenyl groups in the anthracenyl moiety of formula (II) are optionally further substituted by one or more optional substituents, and wherein the phenyl groups in the anthracenyl moiety of formula (II) may optionally bear one or more ionic water-solubilising groups and/or one or more polymerisable groups. 
       
     
     
         26 . (canceled) 
     
     
         27 . A fluorophore of formula (II) as claimed in  claim 25  which is 10-formyl-N-[2-(methoxy)ethyl]-anthracene-1,9-dicarboxylic imide. 
     
     
         28 . A fluorescent sensor compound as claimed in  claim 7  wherein b is one and a and c are zero. 
     
     
         29 . A fluorescent sensor compound as claimed in  claim 1 , wherein the phenyl groups in the anthracenyl moiety of formula (IIa) are optionally further substituted by one or more substituents selected from halogen, C 6-10  aryl, C 1-6  alkyl, C 1-6  alkoxy, C 1-6  haloalkyl, C 1-6  haloalkoxy, hydroxyl, C 1-6  hydroxyalkyl, —SR 4 , —SiR 4 R 5 R 6 , —NR 4 R 5  and —N + R 4 R 5 R 6  groups wherein each R 4 , R 5  and R 6  is the same or different and represents hydrogen or unsubstituted C 1-2  alkyl, and from substituents of formula —COOH, —COOR A , —COH, —COR A , —SOR A , —SO 2 R A , —S03 - , —CONH 2 , —SO 2 NH 2 , —CONHR A , —SO 2 NHR A , —CONR A RB and —SO 2 NR A R B , wherein R A  and RB are the same or different and represent unsubstituted C 1-6  alkyl, C 3-7  carbocyclyl, phenyl or a 5- to 6-membered heteroaryl, or R A  and RB when attached to the same nitrogen atom form a 5- or 6-membered heterocyclyl group, and from phosphine, phosphine oxide, phosphinate, phosphinamide, phosphonate and phosphonamide groups. 
     
     
         30 . A fluorescent sensor compound as claimed in  claim 1 , wherein the fluorophore moiety is represented by formula (IIa′): 
       
         
           
           
               
               
           
         
         wherein:
 R, R 1 ′, a, b and c are as defined in  claim 1  and 
 x is zero or an integer of from 1 to 4; 
 y is zero or 1, with the proviso that when b is 1, y is zero; 
 z is zero or an integer of from 1 to 3; 
 R′, R″ and R′″, when present, are the same or different and are selected from:
 halogen atoms, and cyano, nitro, thiocyanate, C 6-10  aryl, C 1-6  alkyl, C 1-6  alkoxy, C 2-6  alkenyl, C 2-6  alkenyloxy, C 1-6  haloalkyl, C 2-6  haloalkenyl, C 1-6  haloalkoxy, C 2-6  haloalkenyloxy, hydroxyl, C 1-6  hydroxyalkyl, phosphonium salts, phosphines, phosphine oxide, phosphinate, phosphinamide, phosphonite, phosphonate and phosphonamide, —COH, —COCl, —CH 2 OR, —CH 2 NHR, —OR, —NHR, —SR 4 , —SiR 4 R 5 R 6 , —NR 4 R 5  and —N + R 4 R 5 R 6  groups wherein R is (meth)acryl, —CO—C(CH 2 )—CH 3  or —CH 2 —Ph—CH 2 ═CH 2  and each R 4 , R 5  and R 6  is the same or different and represents hydrogen or unsubstituted C 1-2  alkyl; 
 a group —SO 2 R E  where R E  is selected from —NR F R G , —NA 3 A 4 , —NR F A 3 , —OR F  and —OA 3 , where R F  and R G  are the same or different and represent a hydrogen atom or a group selected from C 1-10  alkyl, C 2-10  alkenyl, C 1-10  haloalkyl, C 2-10  haloalkyl or C 1-10  hydroxyalkyl, and where A 3  and A 4  are the same or different and represent a phenyl or 5- to 6-membered heteroaryl group; 
 substituents of formula —COR A , —COR A , —S03 2- , —CONH 2 , —CONHR A , —CONR A R B , —OCONH 2 , —OCONHR A , —OCONR A R B , —NHCOR A , —NR B COR A , —NHCOOR A , —NR B COOR A , —NHSO 2 R A , —NR B SO 2 R A , —NHCONHR B , —NR A CONHR B , —NHCONR A RB or —NR A CONR A RB wherein R A  and R B  are the same or different and represent unsubstituted C 1-6  alkyl, C 3-7  carbocyclyl, phenyl or a 5- to 6-membered heteroaryl, or R A  and R B  when attached to the same nitrogen atom form a 5- or 6-membered heterocyclyl group; 
 a group —COO −  or —COOR where R represents hydrogen, C 1-6  alkyl, C 3-7  carbocyclyl, C 6-10  aryl, 5- to 10-membered heteroaryl or 5- to 10-membered heterocyclyl; 
 a group of formula (A): 
 
 
       
       
         
           
           
               
               
           
         
         where m is 0 or 1, X and Y are the same or different and represent —O—, —S— or —NR— where R is hydrogen or C 1-4  alkyl, n is an integer of from 1 to 20, R x  and R Y  are the same or different and represent hydrogen, C 1-6  alkyl, C 6-10  aryl, 5- to 10-membered heteroaryl or 5- to 10-membered heterocyclyl, and M represents hydrogen, (meth)acryl or 4-vinylbenzene, 
         and wherein the alkyl, carbocyclyl, heterocyclyl, phenyl and heteroaryl groups or moieties in the R′, R″ and R′″ groups discussed above optionally or alternatively bear one or more polymerisable groups and/or one or more ionic water-solubilising groups, or the phenyl and heteroaryl groups and moieties are themselves a cyclic ionic water-solubilising substituent. 
       
     
     
         31 . A fluorescent sensor compound as claimed in  claim 30 , wherein:
 R represents C 1-6  alkyl which is unsubstituted or substituted with one or two substituents selected from Ci-4 alkoxy, hydroxyl, —OSiR′R″R′″, —NR′R″, (meth)acrylate, (meth)acrylamide, vinylbenzyl, N-vinylamide and ionic water-solubilising groups, where R′, R″ and R′″ are the same or different and represent hydrogen or unsubstituted C 1-4  alkyl;   x is zero or 1;   y is zero;   z is zero or 1;   R′, R″ and R′″, when present, are the same or different and represent halogen atoms, or cyano, nitro, thiocyanate, C 6-10  aryl, C 1-6  alkyl, C 1-6  alkoxy, C 2-6  alkenyl, C 2-6  alkenyloxy, C 1-6  haloalkyl, C 2-6  haloalkenyl, C 1-6  haloalkoxy, C 2-6  haloalkenyloxy, hydroxyl, C 1-6  hydroxyalkyl, —COH, —COCl, —SR 4  and —NR 4 R 5  groups wherein each R 4  and R 5  is the same or different and represents hydrogen or unsubstituted C 1-2  alkyl;   
       and wherein the alkyl, carbocyclyl, heterocyclyl, phenyl and heteroaryl groups or moieties in the R′, R″ and R′″ groups discussed above optionally or alternatively bear one or more polymerisable groups and/or one or more ionic water-solubilising groups, or the phenyl and heteroaryl groups and moieties are themselves a cyclic ionic water-solubilising substituent.